Here’s $5, Kevin Hall, go buy yourself a clue

Kevin Hall, the senior NIH researcher recently published a paper in AJCN that has received alot of media attention. This study, he claims, completely refutes the insulin hypothesis so completely that it is now ‘dead’. That’s interesting, I thought, as I sat down to read the article.

Kevin Hall
Kevin Hall

It was a little surprising, therefore to read this paper and realize that Hall’s conclusions were entirely his own opinion. He suffers so badly from confirmation bias that he may as well have written “My mind is already made up regarding the insulin hypothesis. Please do not confuse me with facts”. Confirmation bias is a well-known psychological phenomenon whereby facts that agree with your pre-formed opinion are accepted as true and those that are not, ignored. All facts become filtered through this bias to confirm your previously held opinion. It’s also known as a closed mind.

This happens far more frequently than is often realized or admitted. A similar situation exists in the research behind the weight losing effect of breakfast. Researchers used this question of the proposed effect of breakfast on obesity (PEBO) to look at how researchers consistently interpret results depending upon their beliefs. If you believed breakfast made you lose weight, then studies were interpreted to support this view even if it did not.

Two specific tactics are used – Research lacking Probative Value (RLPV)(association data that can’t prove anything) and biased research reporting (BRR). As more and more people believe something to be true, the effect becomes worse since all research is now interpreted to fit the preconceived facts.BeliefBeyond Evidence2

Starting with the preconceived notion of ‘A’, all research is interpreted to support this belief (B), and all negative studies are ignored (C). This only reinforces the belief (D) which then leads to biased research reporting. This, of course, is a vicious cycle. The same effect is obvious in the Calories In, Calories Out (CICO) diehards.

So, let’s take a closer look at this paper and its claims. The paper is titled “Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men“. Let me give you some background. The award winning science journalist Gary Taubes believes that obesity is essentially a disease of too much insulin – hyperinsulinemia. Since refined carbohydrates stimulate insulin more than fat or protein, reducing said carbs will result in greater fat loss.

He set up the non profit organization NuSi to raise money to fund research and this paper is the first one published. 17 overweight men were admitted to a metabolic ward where all the food they ate were carefully measured. There was a 4 week run-in phase to establish a baseline where men would eat a high carbohydrate, high sugar diet and then switched to a carefully designed low carbohydrate, low sugar diet. Various measurements were then taken, including energy expenditure (EE – how many calories the body is burning), over the next 4 weeks. The basic question is this – does a ketogenic diet (KD) cause fat loss?Kevin Hall 1

Here’s the result. Over the 4 week KD, yes there was fat loss. There was an initial period of greater weight loss which all agree may be some diuresis. We can also agree that insulin levels were brought down by the KD. Secondly, using measures of EE there was an increase in calories burnt. Those are all facts, not opinions, derived straight from the study. Isn’t that a good result?

Well, if you’re Kevin Hall, no. You need to find a way to spin this in a negative way. Then you can tell all your friends in the media so you can declare ‘I was right’. Let’s see how this was done.

When patients embarked on their run in phase, they were switched to a 2700 calorie/day high sugar high carb diet, meant to replicate the Standard American Diet (SAD) that caused the obesity epidemic. Nobody actually believes that this is a healthy diet, and nobody believes it should cause fat loss. But it did. Why? Anybody who has done research knows why. It’s the effect of going into a study and knowing that people are testing you. It’s a universal effect. That’s the precise reason why we have run-in phases. To establish a proper study baseline when people know they are being watched.

So, people lost weight on this SAD diet. But instead of using this new baseline, Hall decides that the downward trend is the new baseline. The unspoken premise or assumption is that if these people had taken another 4 weeks of the SAD, they would continue to lose weight at the same rate indefinitely. WHAT? Are you out of your mind? That’s completely illogical.

Let’s take an analogous situation. Suppose we are teaching math. We teach a semester with no tests, no exams, no checking of homework and no projects. Students are just supposed to spend 1 hour in class and 1 hour of homework a day. They all say they do it. Then, unbeknownst to them, we test them on a standardized test. They do really bad and score 65%.

Next semester, we have daily tests, a final exam, and daily checking of homework. They still spend 1 hour in class and 1 hour of homework. Scores should be theoretically unchanged, because they were doing the same amount of work. Of course, in reality this is completely false. Because they know we are regularly checking them, they do a better job. Now they score 80%

This is the same effect we see when people enter a study. No matter what we are measuring, things improve simply by entering a study. It happens with blood pressure, blood sugars, cholesterol, diets, depression – everything. But the results do not get better indefinitely. It’s a one time benefit. Students score might improve from 65 to 80 in one semester. This does not mean that another semester of testing will raise their scores to 95. Instead they will likely stay at 80. But this is exactly what Hall does – he assumes that this one-time benefit will persist indefinitely.

By making this assumption that the SAD diet will continue to cause fat loss (which logic tells us is false) you can make a positive result negative. So, yes, KD does cause fat loss, but does not INCREASE fat loss and then you can make this your conclusion. Since most of Hall’s journalist friends never read the paper and only the abstract, it’s easy to convince them.

According the Halls assumption, you should therefore simply continue eating the SAD with 25% sugar and expect to lose weight indefinitely. Go ahead. See what happens. I already know. So do you. You’ll get fat, you’ll get type 2 diabetes, and then eventually, I’ll put you on dialysis and chop off your feet when they go gangrenous. But at least Hall can say that he was right.Kevin Hall 2

The second major issue is regarding EE. When you switch from the baseline diet to the KD, the number of calories stays the same. If it causes continued weight loss, then you might expect to see an increase in EE in order for the body to lose weight. This is called a metabolic advantage. Surprise, surprise – that’s exactly what happened. So how can you spin this one? With language.

Look at how Hall describes the absolutely critical increase in EE. Here’s what he writes “the KD coincided with increased EEchamber (57 ± 13 kcal/d, P = 0.0004) and SEE (89 ± 14 kcal/d, P < 0.0001)” (emphasis mine). Hall is telling you that this was merely a coincidence that patients are all burning an extra 57 calories per day. WTF??? There is nothing coincidental about it. You switched them to a KD. EE increased. The P value of 0.0004 means that there is a 99.96% chance that this is NOT COINCIDENCE. Hall knows this as well as I do. This is basic statistics 101. Hall, a mathematician is surely aware of this.Kevin Hall 4

Hall is saying “Oh, we switched their diet to test if EE would increase. It really was just a huge coincidence that all 17 men simultaneously increased their EE altogether at exactly the moment we thought it would. Ignore this, guys. Just write your newspaper article about how this proves it didn’t happen.”

So EE increased and yes, the effect waned over time. What did he expect? That things would continue indefinitely in a straight line? Life doesn’t work that way. Hall had assumed this would happen for fat loss during the SAD, but then correctly points out that EE does not. If doesn’t in either case, dude. Get a clue.

The reason why EE is so critically important is that this is the key to lasting weight loss. Hall had just been profiled in the New York Times cover page measuring the EE of Biggest Loser Contestants. The reason they all regained their weight was that their EE slowed to such a degree that caloric reduction could not keep up. So, an intervention like a ketogenic diet that increases EE is HUGE, GREAT NEWS. Except, of course if you’re Kevin Hall, because it means you were wrong. And you care more about your reputation than people’s health and well-being.Ludwig EE

Dr. David Ludwig, a researcher from a little place called Harvard had shown exactly this same thing in his study from 2012. This study also tested for difference in energy expenditure following different dietary strategies. Once again, as Hall had shown, the EE is best with a very low carbohydrate diet. So Halls study merely confirmed what had already been known.

Some people have also noted that this study controlled calories so it negates one of the KD’s biggest advantages, which is that it makes you feel full. Well, sorry, guys, that’s not the question it is designed to answer. Same goes for the fact that there are only 17 people in it. Again, that’s the study design, so it is what it is, and there’s no use complaining about it.

In the end, the main problem is not the study data. The data are excellent. The problem is the ‘spin’. Here’s the conclusion Hall writes in the abstract’s conclusion (which is the single most important few sentences of the paper, the one that everybody reads)

The isocaloric KD was not accompanied by increased body fat loss but was associated with relatively small increases in EE that were near the limits of detection with the use of state-of-the-art technology.

I’ve highlighted what is fact. I’ve crossed out what is pure spin. Did the KD cause body fat loss? Yes it did. And that’s really, really important. Hall spins it this positive into a negative by moving the goalposts – “Oh but it didn’t do better than before. People eating a 25% sugar diet will continue to lose fat indefinitely at the same rate”. Umm… What planet are you from, Kevin Hall?

Then he says the increase in EE is “relatively small’. So what? Did it increase or not? In fact, your own study from the Biggest Loser suggests that weight loss from constant calorie reduction will DECREASE EE, so even the stabilization (let alone the increase) of EE is critically important. That’s the gold medal, buddy! You just threw it in the garbage.

Hall then downplays this relationship by calling it an ‘association’. As if the change in EE just happened to occur at the same time as the change in diet. What a load of crap. You changed the diet and measured the change in EE. Nobody doubts that. It’s causation, pure and simple. So why try to spin this as an ‘association’ which is a mere ‘coincidence’? Pure spin.

Hall then further tries to downplay the importance of stable EE by saying it’s ‘near the limits of detection with the use of state-of-the-art technology’. So what? Who cares? Did it stabilize or not? Isn’t that great news? Did you not just show that weight loss efforts fail because of decreased EE?

Unfortunately, spin-doctor Hall is now entering a logic free zone, and many journalists like Julia Belluz and other bloggers are happy to take what is shared at face value. “In this first Biggest Loser study, I demonstrate why stable EE is the most critical factor for weight loss. In this second study I’ll show how stable EE is absolutely worthless. Ta Da!” Hall wants desperately to save his own reputation, even if he has to sacrifice your health to do so. Sad. So sad.

The facts alone, without any spin would be this. A ketogenic diet, independent of calories causes fat loss and causes an increase (or at least the stabilization) in EE. That’s the facts. And I love it. Because I can use these fact to help heal patients and save lives. Luckily, I can see Clueless Kevin Hall’s blatantly biased reporting for what it is – the final gasp of the dying paradigm that all calories are equal.

145 Responses

  1. I’m curious what Taubes and Attia have to say to hall about this. Pretty sad for them, that couldn’t have been a cheap study and they chose him to run it.

    • Attia is no longer involved with NUSI, for reasons that are not clear and have not been provided. I personally think that’s a travesty. Someone should say why he’s no longer there.

      • Seems obvious, when looking at Hall’s spin and the fact that he got away with it. I have seen his ridiculous conclusions debunked multiple times now. If I was Attia and at the Helm of NUSI and my researchers would be allowed to spew this kind of nonsense – and get away with it – I would also throw the towel. Pure speculation though.

        • leavemealonegoaway

          Theory: Attia probably saw that Hall was setting it up so that no matter what happened, Hall would have his ‘way’. Maybe Hall threatened to ‘expose’ that NuSi was trying to ‘interfere with science’ unless they backed off. Attia then walks. Who knows?

          Meanwhile, today everybody is upset that Hall is selling tickets to sail the Titanic (the actual trip), despite knowing the ending.

          However, nobody is PRAISING Hall for publishing the actual data!! Hall knows the data shows what it does, actually PUBLISHES IT, then spins it sideways for people with other agendas. The S Fungs of the world can now expose the truth about the data, and spread the word. If Hall were a real crook, he would have fudged or buried the raw data (maybe he tried, but NuSi wouldn’t let him).

          Anyway, I see Hall more as the number one speakeasy owner in prohibition-era Chicago. He has a huge stake in selling Capone’s crap beer, and knows what happens to people who refuse to sell it (see explosion scene..’Untouchables’).

          Instead, he stands at the door (with a gun to his head) telling people “Yes Capone’s beer is awesome” while winking and begging people like Jason to read the fine print….Capone beer actually sucks. It’s all there!!

          I applaud Hall for actually putting his name beside this’s awesome data. Forgive him for being forced to pretend to like Capone beer….he’s brave but not THAT brave.

  2. Did you send him cash or check?

    Dr. Jason Fung: LOL. He’ll have to call me to collect

  3. honeycomb

    The whole industry (of funded research) is a fraud.

    And to add insult to injury they will protect their golden thesis above all else.

    Good work Jason.

  4. Dr Fung, I have read all of your articles, your book, watched your videos, and listened to many of your podcasts. I’ve considered myself to be a big fan of yours. Although I do not have Diabetes, nor am I a LCHF person, I have chosen to respect you and work to follow your advice when it’s been applicable to my body. One of the things I’ve admired most about you is your open acceptance of the fact that there is not a one-size-fits-all solution for Obesity, and that people are different, and many different factors exist. Everyone – including you – values some scientific research over others. However, I am sad to say that I was very disappointed in the tone of this current post, and especially saddened to see your Vitriolic Attack of Kevin Hall, who Is a highly-respected Scientist, and his “bias” was well-known BEFORE Gary Taubes placed him in charge of that Research Project. While disagreements between “exerts” are common, they don’t need to be hateful. The post above might make you even more popular in the Low-Carb community, but not everyone who follows you is a member of it. Personally, I think less of you because of what I read here today.

    Dr. Jason Fung: I see. So Hall can bend the facts to his opinion and because of his position, influence the national media to support the status quo in nutrition, which perpetuates the obesity and type 2 diabetes epidemic. And I am the one who should be sorry for getting angry? What about the 2 people I saw today who got their feet chopped off? What about the 70 people I saw today who have lost their kidneys to their diabetes? Who speaks for them? Who speaks for the dead? You, Phyllis? We SHOULD be angry. And I won’t be afraid to say it, either, if it means that even a single person can reverse their diabetes.

    • What were the “hateful” comments in his article? To me, it’s just a difference of opinion. It also points out that people who are in “charge” will do anything to remain that way, including putting a spin on results. It happens all the time. (And that’s true of Dr. Fung, too: His view will be clouded by his own beliefs.)

      • Oh, let’s see Bob, how about:

        “It was a little surprising, … that Hall’s conclusions were entirely his own opinion. He suffers so badly from confirmation bias that he may as well have written “My mind is already made up regarding the insulin hypothesis. Please do not confuse me with facts”. … a well-known psychological phenomenon whereby facts that agree with your pre-formed opinion are accepted as true and those that are not, ignored. All facts become filtered through this bias to confirm your … closed mind”.

        I have to agree with Phyllis on this one. It’s tone was not professional, it was personal. The way one prevails in a professional pissing contest is to provide, and substantiate, better facts, not insinuation, innuendo, and name calling. Is the reverse true as well? I don’t know Dr Hall. From what I’ve gathered, since the NYTimes Biggest Loser article is Dr Hall is pretty well published. One thing that impressed me with Dr Fung’s book, web casts and 6 part series was his ample use of references, i.e. 34 pages (or there abouts) of Endnotes. This is way better than unsubstantiated claims, but were they cherry picked to match “your pre-formed opinion”? Dr Fung, you just lessened yourself.

        • Hall lied on the study’s result, Dr, Fung exposes him and Dr. Fung is bad because he didn’t just say naughty naughty, you can’t do that!”

          Never mind the real actual results of the test.

          Who do you think you are fooling?

          • Did he?
            Or is it just too hard for Dr. Fung to face the results of the study?
            why cling to a mere use of a single word, as a reason to condemn the whole study?
            and why pick one single point in time, instead of looking at the trend line?

          • Krista

            I love Dr Fung’s passion and attitude in this post! He’s CORRECT and FEARLESS! It’s obvious he is attacking Kevin Hall’s ridiculous (yes, meaning ‘worthy of ridicule’) conclusions, based on KH’s own scientific findings, and NOT KH’s personality or methods. The victimization that you perceive is on you, not him. Scientific truth doesn’t care about your feelings, or anyone’s.

          • seebrina

            Face results? Apparently you’ve never met anyone who was treated for diabetes by the past and current medical community. I watched them kill my mother with their ‘this is a progressive disease’ mantra. Adding insulin to a saturated with insulin problem, coupled with the ada sad american diet insured she couldnt get better and died at age 62 after a slow death struggle with diabetes for 30 years. And to know that all she had to do was get off those horrible medications and sad diet to a diet with fats veggies and fasting and I would still have her here. Studies be damned.. We already know what doesnt work and i dont need a study to tell me that.

    • I was going to write a similar post as Phyllis Collins, but I will just affirm many of her comments regarding this blog posting. Dr Fung your work and writing has been an immeasurable help to me in losing weight. However, I felt the tone of this article was unhelpful in establishing your argument. This blog post is being shared widely on the internet and I think a more professional rhetoric would have made a more positive impact.

    • Richard S Stone

      Phyllis, I disagree entirely. As Dr. Fung points out the analysis by Kevin Hall is essentially fraudulent, utterly deserving of our contempt and ridicule. The gross error needs to be exposed and the errors described in a way to make it noteworthy.

      And Hall’s error is not just some minor issue. The misuse of the data is so gross and blameworthy that it cannot be just accepted as a minor error, or a difference of opinion. The facts from the study are plain to see. Kevin Hall has essentially lied about the state of the research and he is endangering peoples’ lives by doing that. Hall’s spin on the findings are grossly wrong, as is his use of some sliding scale of efficacy which is worse than useless.

      • Well said Richard. My husband and I are living proof that diabetes can be completely reversed by doing exactly what Dr. Fung advises. I’m very sad at how Dr. Fung is being spoken to given he is VOLUNTEERING HIS TIME HERE! Look, we can all take or leave what he has to say, but to be so rude and condescending to Dr. Fung is beyond the pale. How ungrateful. Thanks again for your post Richard S Stone. And thank you Dr. Jason Fung, most of us are very, very grateful for all of your hard work and advise.

        Sue and Tony

      • MachineGhost

        Spinning mind-independent facts contrarywise in abstracts is unfortunately not uncommon in studies. Researchers know journalists and laymen are lazy and ignorant.

    • Danielle

      I get what you mean Phyllis but sometimes this kind of tone is useful in making people wake up and smell the coffee. We are talking people’s LIVES and LIMBS because conventional approaches let us down! How can a “scientist” realistically call himself so when he sees EE dropping as a BAD inevitable thing in the Biggest Loser Study and then downplays EE maintaining (or maybe increasing) in the Keto study. This is at best BAD SCIENCE or at worst SELF-SERVING SPIN. Boo hoo if someone is offended. In any other arena Kevin Hall would get the sack for this kind of error!

      Should Dr Fung perhaps exercise some self control and not get so angry? Maybe it would be better for his stress levels. 🙂 But I guess it was cathartic to write this exposé (feel better Dr Fung?) and I can certainly understand his frustration.

      Look at those poor people on Biggest Loser after they have gained all the weight back and more and even had multiple skin removal surgeries when they slimmed down. It makes me so upset that the conventional approach made them worse off. 🙁

      As always, Dr Fung expressed himself clearly and logically, despite the obvious anger this time. Don’t be disappointed Phyllis. Why not re-read Dr Fung’s points and try to understand the frustration.

    • Debra Smith

      Phyllis, I agree. The tone was angry and ridiculing. However, if you think about, it’s because Dr. Fung cares about his patients and wants to share his scientific theories with anyone willing to have an open mind. I’m a retired nurse and I have been exposed to the toll of suffering. Millions of people, more than the hallocaust, are being made sick, kept sick, and are suffering excruciating pain. Legs are whittled away, blindness, heart disease, kidney failure, terrible infections…..the list goes on and on. Until you smell your fellow man from the hallway, with a gangrenous foot, don’t be disappointed in Dr. Fung. He’s one of few doctors that try to find answers to the causes of this blight. He’s a scientist, following the scientific method. I wish my doctor wasn’t a sheep, never thinking about treating the cause of a disease, only symptoms, following protocols that have proven to be failures and never! questioning the care he provides.

      More healthcare workers should be outraged. We’re supposed to be scientists. Most of us don’t know how to interpret studies or even do them properly. If something is true, further studies should be able to be done to verify it, over and over again. I’m sick of these ridiculous
      studies. The misinterpretation or the lack of doing long term studies is killing us, just slow enough to make money from our suffering.
      I will put up with Dr. Fung’s sarcasm and anger. I hope he keeps screaming his ideas across the Internet. I sometimes feel “crazy”. Why do we believe the FDA, USDA, AMA, the AHA or the ADA’s suggestions? Clearly they have FAILED and betrayed their fellow man for financial gain. It’s the most awful conspiracy of all time. As long as the healthcare industry is supported by people made sick by their own government, we don’t have enough resources to provide care for other diseases or prevention.

      So, I’m screaming mad inside. Do no harm, that’s an oath that has been betrayed.

      • Thank you for such a good post in support of Dr. Fung. And this folks, coming from a retired nurse. I’m with you Debra. Job well done Dr. Fung!

      • Me too. Well said Debra! Thank you for your professional opinion in support of Dr. Fung. I am just a lay person with my own evidence but no funded research or study. I have been angry for a while now because of bad information given by doctors to my sister (type 1 diabetic), my dad (kidney failure), both of my grandfathers, and now my husband (type 2). I am sitting on the sidelines watching this train wreck. I have type 2 but have been reversing it since October 2015 with NO medications only LCHF, IF, and recently added regular exercise to the game plan. I check four places every day for new information or just encouragement to stick with it: Dr. Fung/IDM,, and the two facebook pages TypeOneGrit and BurnFatNotSugar. Without the help (and straight-shooting) from these places, I would still be following the American Diabetes Association’s bad advice of how to eat for diabetics that I began learning at age 10, when my sister was first diagnosed. Keep up the good work Dr. Fung!! And thanks for caring about us!! I am only sad/angry that I can not time travel with these truths to help people I love avoid the complications of bad info.?

    • I agree, Dr. Fung’s tone was one of attack and ridicule. However, I do not find this to be very remote from his usual tone. A mild-mannered, polite doc would not manage to get his against-dietary-recommendations message across. For those of us who owe Dr. Fung gratitude, he could not have done it without a belligerent attitude. Cheers.

      • With half-assed attitude like yours, millions of diabetic in the world will continue to suffer and die. Cowards like you are directly responsible for this disaster. You should be ashamed, you protect the $y$tem.

    • It is not anger but passion. One is from hatred, the other is from love.

    • Dr. Fung has always been witty and hip. This is nothing too new from his rhetoric. Is it effective for the laypersons? Yes I believe it is. Is it wholly professional? No, but this is not a comment in a scientific journal, there is no need to be. It’s a different medium, it calls for different rhetoric. For a blog post, this is fine.

  5. Dr. Fung I love your work. Nevertheless there is a more direct explanation concerning the spin by Kevin Hall. I present another analysis based on the fact that KOLs (Key Opinion Leaders) are made by industry based upon their loyalty. This is another example of spin favoring industry. I strong recommend if you want to know how bad it is to read, and reread the BMJ award winning book by, Prof Peter Goetzsche, Deadly Medicines and Organized Crime: How Big Pharma Has Corrupted Healthcare, and also Bad Pharma by Prof. Ben Goldacre,

    Kevin is a KOL (Key Opinion Leader), and this article could well have been ghost written by a company specializing in ghost writing. One study “found evidence of ghost authorship in 75 percent of cases?” (Prof. Ben Goldacre, Bad Pharma p. 289). One indicator of ghost writing is the number of studies and other articles the KOLs name appears on. Another red flag is when the media wide reports on the study, and what they report is in the interest of pharma or food manufacturers, then it is likely that the article carried by the news service and has been ghost written for the reporter to sign off on. The news service is pleasing a major advertiser/industry. See Ben Goldacre’s Bad Science for examples of this. A third red flag is when the conclusion of a journal article is spun to favor industry. And a fourth is flaws in the procedure designed to give the desired answer, like using the poorly absorbed crystalline form of COQ10 instead of the micronized form suspended in oil, and also to run the trial on Parkinson’s disease for only one year on a sample too small to show statistically significant results. You now got the drift. The article was either ghost written, or written with results favoring the company which funded NuSi, the organization Hall set up to do the study. That Kevin got funding is good reason to believe that industry in some way donated the money. And if government funded, I suspect the same bias as industry funded studies, such is the track record of the NIH. Kevin D (KD) Hall name appears on over 50 articles in the last 14 year, all with multiple published versions (Google Scholar search).

    One final comment, without submission of the raw data, a peer review has no way of knowing if various changes in the data or trial protocol had occurred. Thus peer review is depending on the honor of an industry ran on what I call “tobacco ethics” (profits before truth)/people).

    Hopefully this opinion of mine and others on bad pharma has found receptive ears.

  6. They labeled the low carb diet as KD (ketogenic diet) but they made no attempt to verify if the people were in ketosis, and the period of time they were on the low carb diet was very short, they probably were never in ketosis. It did seem that the total number of grams of carbs were too high.

    • I believe the full published paper does show blood ketone levels at about 0.8 mmol/l from memory.

      The study was supposed to be isocaloric and eucaloric so there should have been no ongoing weight loss by the end of the run-in phase.

      Personally I think any ketogenic study needs to start after at least 2 weeks on Atkins Induction or similar to at least get “in the zone” otherwise we’re doing science in an unstable transitional state which is seldom good when trying to understand long term effects.

  7. I normally agree with you Dr. Fung, but I find this study to be quite weak.

    Small sample size (17 men), small duration in time (4+4 weeks), and no control group.

    The phase-in was 4 weeks of 2,700 calories a day of SAD. But for all we know these men used to eat 3,500 calories a day. They were obese men, if that is the case the phase-in would need to be a lot more than 4 weeks. In other fields of science, periods of “phase-in” are used for computer simulations, and they continue until the distribution converges to an initial range. There’s no convergence here. You talk about placebo effect but there’s no reason to assume that it would last exactly four weeks.

    They then go on a ketogenic diet for … 4 weeks. Great.

    If I can critique Kevin Hall here, it’s that he’s making spectacular conclusions off extremely weak evidence. It really doesn’t matter what this microstudy of his demonstrates, as long as the result is small (which it is) it’s hard to be convinced.

    Why does he lack the modesty to say “further research is warranted”?

    Dr. Jason Fung: Yes, I agree. This study is exceptionally weak. My response was to the national media attention it is getting, from journalists like Julia Belluz and Marion Nestle that use this study to proclaim that the ‘insulin hypothesis is dead’.

    • David,

      You’ve missed the most important thing that Dr. Fung points out: Dr. Hall’s sign is wrong.

      I used to work with a very smart analyst who had gotten his doctorate at Rand. His favorite saying about analysis was: first, make sure that you get the sign right. Is this a positive effect, or a negative effect? Then and only then, try to measure how much of an effect there is.

      Doing what Dr. Hall advocates (Calorie Reduction) produces a lowered Energy Expenditure (EE). Due to the lowered EE, it becomes impossible to stay in the weight loss period, or even maintain the weight loss with a lowered calorie diet. This is a “negative sign,” and should worry anyone who wants to lose weight.

      Doing what this study is promoting (low carb high fat) produces an increased EE. Due to the increased EE, it becomes possible to remain in the weight loss period longer, and even when EE returns to baseline, maintaining that weight loss should be possible. This is a “positive sign,” and therefore indicates a substantial difference over the negative sign. To say anything else is to ignore the importance of the difference between positive and negative.

      • sten bjorsell

        I checked and you are spot on ! The abstract says that the diet was reduced by approx. 300 kcal per day, or 10%. The result states marginally increased energy expenditure, absolute minimum absence of reduction also by Kevin Hall’s report, which as you point out is the complete opposite to a standard calorie reduced diet. Thanks!
        It means the insulin hypothesis is a step closer to be fully proven.
        For full proof a longer study including control group.

    • sten bjorsell

      Surprised they did not have a low fat control group. Just splitting this group in half would have told more than now, guess at same cost. Since reduced calorie ketogenic diet does not reduce EE but reduced calorie SAD or low fat diet reduces EE, the missing comparison study is obvious and would end the debacle, since opposite EE trends hardly can be explained away.

  8. Yes, David, study is weak, but it is still important to acknowledge that Hall’s interpretation of it is off, to say the least.

    Jerome, Hall did not set up NuSi. Those who did made a big mistake dealing with him.

    Dr Fung, your reliance on the idea that people magically do better when tested worries me a bit. This was a metabolic ward study afterall. Can you help me out?

    • Bob:
      ever heard of the placebo effect? We’ve found people become stronger, faster, healthier, and overall better at everything once they are part of a study. We’ve even had disease symptoms disappear just by putting people in studies. It’s very powerful, which is why most studies have a control group. It’s a known scientific fact that once you observe something, what you are observing will change from baseline.

      • There have been studies where they tell people they’re getting a placebo, and the people still perceive an improvement. EG:

        I think anytime you are watched at anything, you’ll be better that that thing. This is particularly true in nutrition, especially for things like food diaries. If you have someone weigh all their food, you’ll get a much better sense of intake then if they write a food diary (where they’ll conveniently “forget” they ate that evil hamburger with its saturated fat).

  9. Wenchypoo

    “My mind is already made up regarding . Please do not confuse me with facts”

    This is American politics all over–especially the GOP right now. Is Kevin Hall by chance a Republican? 🙂

    • George Thomas

      “hurr durr republicans r stoopid hurr durrrrr”

      So brave.

    • I would say the same about the liberals. Not a fact in sight just everyone pooping sparkles as deemed by the liar hill

  10. Well said, Jason. This is exactly what we’ve been saying when asked about this study.

  11. Jason,
    It is not necessary to evaluate Hall’s study. The list of studies from your Youtube, I think called Etiology of Obesity, shows direct link between insulin and weight gain. I think it would be good to lay out the details of those studies. If you send me the direct links or better, the pdf’s of the papers, I will do it (I wish I hadn’t said that).

  12. Ann Patterson

    Dear Dr. Fung, Thank you for once again clearly cutting through the bullshit. In Taube’s desire to bring new, credible and unbiased research to this arena, it seems he let the fox into the hen house. Wonder how he’s feeling about the value of NUSi after this release. Fondly, Ann

  13. Robert Lockridge

    Dr. Fung, what matters is that you are saving lives in your clinic. Your methods are based on a preponderance of the evidence, which in such a complicated field as nutrition’s relationship to disease is all we’re going to get. At almost seventy years of age, I have lost fat, gained strength and muscle mass, greatly alleviated my idiopathic peripheral neuropathy, and gained mobility and energy using intermuttent fasting and a low carb diet. My trygs are 43, HDL 63. Pretty strong ratio. I credit you and others like you, including Dr. Feinman, Gary Taubes, Nina Teicholz, Denise Minger and Dr. Mark Hyman with giving me the guidance I needed to reverse a lifetime of chronic morbid obesity punctuated by remission and relapse following the Duetary Standards. Keep up the good work.

    • If you did look at the study, change from the SAD to ketogenic diet also resulted in the greatest decrease in triglycerides.

  14. A second look at Halls work reveals the straw man criticism. The RC (restricted carbs) was not a ketogenic diet.

    As pointed out in the Obesity Code (190-193, the stomach and the duodenum cause the production of insulin through the release of incretin hormones. The insulin index of fish is 59, meat 51, and cheese of 45,yet they have near zero carbohydrates. Apples is 59, white pasta 40, and croissants 79. Thus a lower carbohydrate diet does not equate to a low protein diet. Moreover the carbohydrate percentage was reduced; it wasn’t a ketogenic diet. Lower carbs is not the same as a ketogenic diet. The RF phase with 71% of calories from carbs including 35% from sugar. It was too short to produce the long-term effect of high fructose from the disaccharide sucrose through glycation (reactive oxygen species). Fructose is toxic to the liver (a point repeated made by Prof. Robert Lustig), see his Fat Chance). It is 7.5 times more reactive than glucose. The RC diet was 21% protein, 50% fat, and 29% carbohydrate with ~8% sugar. (from interview at Note this deviates from the protocol that called for a ketogenic diet of 5% carbs (from at The trial is too short to produce significant differences; moreover it is not testing the carbohydrate theory because it is not a ketogenic diet. Finally, the difference between two diets the restrict calories one ketogenic the other not is not very large, as Dr. Fung had pointed out in his blog on the A to Z trial at 1 year. Fasting is required for a low insulin diet, which accounts for Dr. Fung’s treatment success.

    • Table 2, page 5 of 10 of Hall’s study: Carb intake g/day 35.8 +/- 4.7, <2% from sugars; Fat intake, g/day 242 +/- 8.2; protein g/d 104 +/- 4.1; energy intake 2738 +/- 108. Carb: Fat: Protein ratio 5.2%: 79.5%: 15.3%. Low carb diet was most definitely ketogenic. More to comment on regarding this blog and others but will leave that for my upcoming response at

  15. Hi Jason do you know that, bros write blogs .Why don’t you go ahead and comment in the paper? It takes courage, isn’t it?Good luck and looking forward to some actual discussion and coming up with a solution rather than blogging . Hope you don’t censor this comment.

  16. As a former low carer and one who was in ketosis for 12 weeks, I did in fact lean out. The problem for me was that I could not perform at a high level in my chosen sport (ice hockey). I just did not have any explosive anaerobic power and everyone was asking what was wrong with me. Now at 52, I still play ice hockey with the young folks, I do carry more bodyfat than I want, but it is what it ideal carb intake of about 200gr per day provides what I need. No diabetes, no unstable blood sugar. Fruits and veggies are my choice for carbs with occassional lentils. So both ways of lifestyle earing seem to help people in different ways.

    • Robert Lockridge

      Some pretty convincing work done at UCSF seems to show that LCHF is most effective for folks with some degree of insulin resistance, while insulin sensitive subjects do ok on higher carbs. When you think about it, this is not surprising. Since T2D is a disease of insulin resistance, I think LCHF should at least be tried. We all have to do our own n=1 trial and adopt what is most beneficial for us. The dangerous aspect of Hall’s analysis is that it implies that this study categorically refutes the working assumption that LCHF can reduce insulin levels and thereby benefit diabetics and obese persons. This is clearly not the case, as amply demonstrated in the scientific literature and in a wealth of case studies and anecdotal testimonials.

      • I agree with the above two points anecdotally.

        I’m 40, have about 18% bodyfat and did try 12 weeks of ketogenic diet to make sure I gave it a fair shot and I was keto adapted. I also used ketostix to ensure I was in ketosis. Yes, I did lean out (from prior 25% bodyfat) but was completely lacking power in the gym and the depression hit like a Mack Truck. Like sitting in my car crying depression.

        I function better at around 200-250 grams carbs.

        Having said that I fully agree with the science and even for high-carbers, a cycle of fasting / low carb during the day or during the week can likely be beneficial for maintaining insulin sensitivity.

        My $ 0.02

    • You can also consider a cyclical ketogenic diet. (Eat Carbs before hockey -> glycogen depletion -> keto)

  17. Science and evidence about breakfast, body weight and obesity:

  18. Deb Griffith

    They don’t have to do expensive studies and trials to prove that low carb works(proving the low insulin theory is very much alive and well). All they have to do is cou t us hundreds of thousands of older people who spent decades on the CRAP or cico or SAD methods of eating and stayed fat, who are now called SKINNY at family functions after a year of LC and IF.

    • Well said Deb. My sister works with a nurse. She is 64 years young. 10 years ago she had suffered 3 heart attacks, , 7 stents, had high blood pressure and was T2D. As a NURSE she went completely against all advise and tried LCHF. Today, she is in perfect health. Her weight is good, takes no medication and is free of her T2D. She has been on the diet for 10 years. That speaks volumes. LCHF + fasting works for her, it has worked for us and if people followed the advise like they should, it will work for them too.

  19. Sue and Tony

    Dear Dr Jason Fung,

    As for my husband and myself we will be eternally grateful for all of your hard work and effort on the behalf of good medicine and excellent communication. We have followed your advice verbatim and without a doubt, my husband most certainly wouldn’t be where he is today (in perfect health) had it not been for you. And we LOVE your “tone”. There is nothing wrong with calling it like it is without the sugar coating. (Another reason to hate sugar 😉 Lively conversation is one thing, but to criticize how you volunteer all of your good time and knowledge for those of us struggling, in my opinion, is inexcusable.

    As for all of you who have some kind of beef with the good doctor, please keep something in mind. He is trying to help people with diabetes and obesity because he is an exceptional human being and a class act REAL doctor. One that does house calls via these blogs. He doesn’t have to do this for us. He could go back to “just” being a Kidney Specialist. His book, The Obesity Code, cost $11.00. He’s hardly getting rich on it. We anxiously are awaiting your book devoted entirely to diabetes. (Can you write faster, LOL) But in the meantime we so look forward to every Thursday so we can glean whatever good advice you are willing to give.

    With much respect, admiration and gratitude,

    Sue and Tony

  20. I think the last paragraph of the paper is the most interesting… “However it is possible that dietary carbohydrate restriction might result in decreased ad libitum energy intake – a prediction of the carbohydrate insulin model that we as not tested in the current study but deserves further investigation.”

    Hall’s closed system model does not account for insulin resistance or appetite which are critical.

    Sunk Cost Fallacy = “Your decisions are tainted by the emotional investments you accumulate, and the more you invest in something the harder it becomes to abandon it.

    It would be a bad Hall indeed if he found that insulin resistance is the missing variable form his model that drives real people outside a metabolic ward to eat more because they can’t access their own fat stores when they are feasting on carbs.

    • “because they can’t access their own fat stores when they are feasting on carbs.” When you hear people saying they go to the gym and simply can’t do their usual workout, that’s them saying they aren’t tapping their fat reserves either.

      Marty, I’ve been doing low carb/IF for 2 months now and gained weight… I have gotten very skeptical about all the happy ears on this whole Fung bandwagon. I’ve asked for clarification on points only to hear just the crickets. If I am not mistaken comparing ketogenic to low carb is misleading as keto, to my understanding is VLC (10g/day or less). I tell MFP to make carbs 30% and I generally come in under that. BTW, my core temp has dropped over 2 degrees w/ lc and IF.

      • I agree it’s not just as simple as IF plus LCHF for lots of people. Calories still do count. Lots of people can get caught with “fat to satiety” and satiety doesn’t always kick in in time. It some people more than diet and IF to change their metabolism to the point that they can tap into their fat stores. Personally I’ve found the approach detailed in this article useful to make sure I’m moving forward.

        • Thanks Marty for your comments. I agree that the “eat fat to satiety” can be bad advice. I know that one of the things that has kept me overweight has been that I don’t understand true satiety. If I’m honest I know that often my hunger knows no bounds. This is not just biological, something that can be solved by “eating a pat of butter”, but is also psychological, and a need to use food for stress relief and comfort. I have lost 37 pounds (25 more to goal weight) since April 26 following LCHF and IF, but I have set specific macronutrient/calorie goals and tracked religiously. The discipline of setting reasonable goals and tracking is helping to retrain my brain to understand satiety. IF has been great for losing fat, but even greater for helping to free me from food addiction

          • @Krista, one thing to keep in mind… The brain has a very hard time distinguishing thirst from hunger. So, perhaps, much of the time you feel hunger, it is entirely possible you are actually dehydrated.

            Some say have 8 glasses of water/day. Some say have 2 liters of water per day, some say have so many oz of water per pound of body weight per day. I believe the safest advice is you want your urine to be just faintly colored. If there is any appreciable color to it, you are dehydrated. But, I am not a doctor. I think going on urine color is way more accurate than ‘what size is “glass” of water’, or, ‘are you telling a 200lb woman I should have the same water/day as a 100lb woman or a 300lb man’?

      • sten bjorsell

        Hello Walt!
        Carbs alone doesn’t count the insulinogenic foods…
        Check post above by Jerome Benthamite !
        If still not sure, check that your fasting insulin is well below 5 !

      • @Walt, I’ve read your comments on the previous blog entry too and see you are getting frustrated. What you have described, eating one meal of 800 cal/day, I don’t believe is intermittent fasting. It’s modified long term fasting. I think Dr Fung recommends you eat till satisfied to complete the cycle.

        Earlier you asked what is the functional or metabolic difference between a continuous intermittent 24 hour fast, a daily single low calorie meal and water and vitamins only? I don’t have an answer, but I understand that low or zero calorie fasts longer that 5 days will slowly lower TEE (there was a chart somewhere on this site – I remember 3 days being the peak TEE boost). I can’t explain the mechanism, but it makes sense the body needs to be reassured food is going to be available or it’ll preserve itself and slow the metabolism.

        Perhaps, if you don’t want to increase the calories of your daily meal, consider fasting one day and eating a 1600 calorie meal every other day(or till satisfied). This feast might be enough. From what I’ve read in these blog entries is it’s not about the calories, it is about working with the bodies hormone system.

        Remember stress is part of the equation too. And that medium chain fats like coconut oil help boost metabolism.

        Good luck!

        • Hi Rob, how perceptive! That was a nice way of putting it. The 800 came from fusing the Taylor/Mosley protocol with the Fung protocol. How’s that saying go, “when you find you’ve been digging yourself into a hole, STOP DIGGING”. I had found no conclusive, ‘now that you’ve screwed your metabolism…” so, yeah, I was very concerned. I was not looking for free medical advice, rather, was I misinterpreting the book and, if so, how. Plus, frankly, there are contradictions in the book that one was either left to noodle through themselves guessing at a missing differentiator, or chalk it up to internet marketing, next new fad. What I thought made perfect sense, but it was my own solution to one of the contradictions, is that if, according to Mifflin and St Jeor, I should be requiring 2000 cals/day and I only supplied 800-1000 the other 1,000 would obligingly come from fat. That it wasn’t happening that way, was an insulin resistance side effect and, not until I solved that issue would I see a seamless transition, ala thermostat vs binary switch, you either burn recently ingested food OR you burn fat. This would be supported, by inference, in the section where Fung talks about the 60’s and 70’s 3 meals/day with 2 mini fasts and 1 much larger fast working just fine to control weight and it wasn’t until the grazing fad started that the wheels flew off the buggy. Not to be repetitious but having lost about 120lbs in the last 15 or so months, I’ve worked too long and too hard to turn down the wrong side street only to find I blow up like a helium balloon which, I fear, has started. Again, thanks Rob.

      • What points would you like clarification on?

  21. remberto

    I have normal weight (23 BMI) and wonder if I ever became insulin resistant and adopted the fasting and LCHF protocols, wouldn’t I become too skinny?

  22. Low carbs followers usually starts out misinformed ,pigs out and develops IR and then preaches low carb.Lift weight ,would you?I have never gained so much fat to loose.Guess what I am more informed than most of IR guys on low carb.

  23. sten bjorsell

    Since food intake was down 10% on the ketogenic diet and metabolism did not drop – which it does on calorie restricted SAD diet for most, the study results show that ketogenic calorie restriction does not reduce metabolism and therefore works fine for weight loss while SAD reduces metabolism as seen earlier with poor weight loss as discussed above by/with Jason.

    A few things missing to get full proof in a single study:
    1/ A control group on same calories as the ketogenic group eating SAD is required.
    2/ Fasting insulin (lowest cost measure of insulin resistance) required at start and end of trial.
    3/ Groups to be monitored after study, until 50% of lost weight regained in the group with poor outcome.
    4/ Participants to be obese with some minimum body fat limit at study start.

    I expect following results:
    a/ A minimally retained metabolism in the ketogenic group resulting in larger and sustained weight loss, while the SAD group will reduce metabolism and lose less weight which is later often regained.
    b/ Clearly lowered insulin resistance (IR) in the ketogenic group and close to unchanged IR in the SAD group.

    If the results as per above the current “Insulin Hypothesis” should be renamed to “The Insulin Effect”, as this is the effect preventing sustainable weight loss when eating a calorie reduced high carb SAD, apart from being the hormonal cause of obesity in the first place.
    The direct reason for slowed down weight loss followed by regained weight is already established, reduced metabolism.

    The explanation of the role of insulin in the two groups is short (and sweet):
    The SAD dieters (Biggest losers in more than one sense) reduce insulin before each new meal, but their insulin levels are then brought back up again during and after every meal. Between meals when same food energy is used up their insulin remains too high to allow liver stores and body fat to be burnt “on demand”. By the time the insulin has dropped to a level to release stored energy, SAD eaters are however re-fed with food that raises their insulin again! The effect is that around half way between meals total energy supplies (already reduced from normal in study!) are not sufficient to maintain normal metabolism as body fat (and maybe also liver glycogen) is locked up by high insulin, resulting in a temporary emergency(!) reduction in metabolism to keep essential for life metabolism going as “nothing else is readily available”. The typical immediate result is lowered body temperature, which then has nothing to do with the Thyroid!

    The story is however completely different in the ketogenic group consuming mainly fat, the same “food” as “body fat” is when we don’t eat. Fat has near zero insulin raising effect and circulating insulin is therefore lowered for every day that pass on this diet. After a few days if starting off on a SAD, the lower insulin enables the body to freely burn fats from food or body fat to satisfy all metabolic needs at all times. The effect is a seamless change over between body fat and food fat. Metabolic reduction never required, except the first (few) days, time in proportion to insulin resistance starting off. (Hence more or less impossible for an obese subject to come near with 3 SAD meals per day.)

    As far as I can see that is the Q.E.D. of “The Insulin Effect”, still awaiting the practical proof in a single study !

    (More good keto-news: since moderate exercise has overall good health effects, it is interesting to note that exercise added in above SAD eating group will reduce metabolism(mean body temperature) further as there is already a calorie shortage without exercise and fat stores are nearly unreachable. If exercise immediately prior to meals lowers insulin enough, fat could be burnt in a short window before next meal raises insulin again. In the ketogenic test group exercise would however only give one effect: accelerated fat loss!

    • Hi Sten,
      This is ever so frustrating for me. In a word, it’s not working and, trust me, I so want it to. My journey, for lack of a better word, started with trying to replicate the results of the New Castle study that, after a mere 8 weeks, reversed T2D in a number of diabetics of various length of the disease. Eight week on a CRaP diet. This was Dr Roy Taylor. His results have been reproduced by others and replicated in follow on studies with people with longer periods of T2D. Initially, I did not have their diet so I simply used MFP and told it to lose 2lbs/week. At 10 months I had lost about 100lbs, not the 2-3 Dr Fung suggests. But, as Dr Fung suggested, at about 6 months I stalled, double downed, and at 9 months stalled again. Dr Mosley’s 8 week blood sugar diet is effectively Dr Taylor’s but to a Mediterranean beat. I merged the two shooting for, initially, 800cal during a 3 hr window with 21 hrs of fasting. I’ve done a lot of research on adaptive thermogenics / metabolism (damage/resistance/impairment). I am scared to death I’ve wedged myself at this point, now that my 8 weeks are up and I’ve started to actually gain weight, on a sub 1000 cal/day diet.
      While Dr Fung doesn’t directly advocate any given caloric budget looking at OC appendix A, they appear to also be sub-1000 cal/day.
      What I find fascinating though is the optics of this conversation from the perspective of different audiences. Diabetics read it one way, people with BMIs below 20 read it another way, body builders read it yet another way. Oh, and then there is the 2 degree drop in core body temp. This while fasting 21hrs/day.

      I’ve asked people who claim fasting is such a Godsend for them and their weight loss is phenomenal, exactly what weight loss did they see. The response, crickets, except for one woman who, as I recall, said about .5 (1/2) cals/wk. I am going to seek out an Endocrinologist. My regular health care folk are still at the chronic, progressive, life long disease way of thinking. Whenever a problem is approached as it won’t and can’t get better, there often is little effort to make it better.

      • sten bjorsell

        Hi Walt,
        I followed Dr Fung’s fasting “the longer the better” way last April. I planned to do 2-3 days fasting in a row, as the time to bring down the insulin at the start of each fast would then not be lost. I mean there is hardly any fat burning until insulin is down enough, which can take 1 – 2 days of water fasting! (i drank water with a lemon squeezed in 2 liters ow pure water. Added a bit of gray sea salt after a few days..) After the 2nd day fasting like that I had so much energy and no hunger that I just saw no point in stopping. Later coming up to 5 days I could have continued but decided to stop as I was in totally uncharted water and without medical assistance. I started the fast Sunday night after evening dinner and finished following Friday evening dinner. Worked a normal all week. Apart from lemon water I had many cups of black coffee without sugar. I felt great and had a rather large dinner at the end of my first 5 day fast. But in the middle of the following night I awoke with stomach pain out of the blue, which went with a glass of boiled warm water. I checked Fung’s articles and the 2nd week I started with bone broth day 4 , gradually increasing it on the two last days until dinner time. Much better transition !
        Same the 3rd week, all 3 weeks in one 5:2 “sweep”. I lost 9 kgs from 92 to 83 kg. After I have been eating normal low carb, maybe a little more carbs as I now have found out how I can easily lose them if I want. I regained 1 kg, now 84. Never freezing. The key is water fasting at least 2 days in a row. Forget Taylors 1000 calories per day. Since it is carb based it will never reduce the insulin enough and 90% of his patients regain all the lost weight again, and I suppose freeze during their fasts due to the metabolic drawbacks of reducing a non ketogenic diet. Taylor’s contribution is that he measured liver fat with special MRI and saw it reduce at the same time as blood sugar control returned, proving that diabetes 2 can be reversed. Moosely has done a greater favor as he has pread the word about fasting to a greater audience, making it acceptable. And for a friend of mine with heart disease that jumped on it and missed out on that one was allowed to eat some 1000 calories per day. That saved his day so after a year of that his doctor could not believe that all is bloods and blood pressure readings suddenly were perfect! Moosley’s contribution must be in that he spread fasting as a tool to a wider audience via semi-fasting . It seems he is now becoming a bit stricter, something both his old and new followers (5:2 the other way around) definitely will gain from!
        My advice is to try water fasting 2-3 days and if you cannot “do it”, go strict ketogenic first, for at least a week, as the transition from burning fat from dietary fat to burn body fat then became nearly totally seamless, at least for me. A hidden benefit of fasting apart from reducing insulin and thereby insulin resistance is that parts of our bodies during fasting start chasing proteins inside us, like (free!) cleaning patrols scavenging “every cell” for anything edible, which includes proteins in inflammations and plaque and fats in the wrong places. That’s why I in part agree with what Richard S Stone says below: Fasting works forever. Give it a try, but at least 2 days in a row now since you have failed before. Zero external calories during fasting, but water and (gray) salt is fine. Gray salt contains sulphur helping the liver to bind up toxins and also all the magnesium originally in the sea salt, both taken out in “white” sea salt!

        • Thank you Sten! That was an outstanding reply…and actually answered, in part, a question I had asked weeks ago, blogs ago. If you look at page 239 (I know it by heart now) and look at the categories, specifically post absorbtive phase, if that occurs up to 24 hrs after feeding stops but you do a 24hr fast, which really means 18:6 or 20:4 or 22:2, how does phase 2 ever start? Ditto, and worse, with gluconeogenesis and, even more the case, ketosis? Absent a response to that (prior to yours just now) I figured it was a flaw in the IF model as those phases can never occur unless you do a water diet which Fung even claims requires strict medical supervision. Hey, while I have your attention, let me ask you directly another question I was hoping to get Fung to clarify. He states with fasting there is no metabolic adaptation (yet doesn’t really show how). My question was can fasting resolve existing metabolic adaptation. I assume my core body temp, reduced heart rate, shallow breathing, was due to a (badly?) compromised metabolism. I’ve reseached things that say it is likely my ‘new normal’ and others saying it is possible to correct it in a few days to a few months, specifically, maybe either through eat less move less to eat more move more all without clear likes of demarcation. The 24hr fasting, which is to say, the 21:3 fasting I tolerate near perfectly. I’d say most days perfectly, rarely though, it is a real struggle come about early to mid afternoon. How did you find four to five days? Again, thank you!

    • Sten, a very important fact I failed to mention. In my last, likely over 8 weeks, there have been, with very rare exception (1/2 slice cheese cake 50% fat 50% carbs) there have been NO sugars and no refined carbs.

      • sten bjorsell

        The cheese cakes have to go, at least if you get through my reply above…. But not on all days you don’t fast although don’t treat yourself the days just before next fast, clear from above too.

        • 🙂 That was a birthday thing coupled with having lost over 100lbs over the course of the prior 11 months. That was my ‘brass ring”.

  24. Richard S Stone

    If i understand what Dr. Fung is proposing, throughout his work, it is that the cause of obesity is insulin, but that insulin resistance (diabetes…) is a far more important issue. Still, if you reduce insulin you will lose weight. Second, “diets” don’t work at dealing with either issue on a long term basis. The one and only thing that works long term is fasting: Not Eating. Not Eating works because if you don’t eat you simply Do Not generate any insulin. Insulin is generated mainly by consumption of carbohydrates/sugars; And, more surprisingly, by protein. Fat isn’t an issue. Green vegetables do not seem to be much of an issue.

    (This, to me, on a evolutionary level, seems most interesting. Could this be some hint, or clue,about what people are designed to eat as the bulk of their diet? Fat, green vegetables, protein, and carbohydrates, in about that order of preference?? Who knew? Lots of people, actually.)

    So to me it does not seem particularly significant that LCHF diets are not enough, on their own, to greatly reduce weight, and keep it off, etc. But I know such diets work: Just not forever.

    What works forever, and always, is FASTING. When you don’t eat you don’t generate insulin. And you lose weight. The Kevin Hall interpretation of the study and data is a sad, misleading joke.

  25. I should probably clarify what I said earlier for the benefit of the reality tv folks and Jerry Springer fans cheering on Dr Fung’s retort to Dr Hall. First off, I did not weigh in on the efficacy of a LCHF diet vs an Atkins style or HCLF. I do question how many posters here actually read his book, as he states very clearly:
    1) all diets work, all diets fail. (that, btw, includes LCHF).
    2) In referring to the decline of the Atkins diet, Fung states, regarding the carbohydrate-insulin hypothesis (the basis for Atkins) “The hypothesis stands incomplete. There are many problems with it, the paradox of … being just one of them”. For you fact checkers, that is towards the bottom of page 103.

    The notion that if you don’t eat you don’t generate insulin is patently untrue. Fung, Obesity Code, page 114, “the greater the resistance, the higher the levels (of insulin in the body)”. This by way of explaining that the body will generate more insulin to overcome the resistance, thereby creating a greater resistance. This occurs whether you are fasting or not, it’s not either or, its level of degree.

    For those that are, practically, saying, “Dr Fung, hit him again, harder, harder” (food fight food fight). It would help if everybody actually read the book.

    My initial comment did not address the truth or interpretation of data. Rather, it addressed the manner in which this blog entry was written. It wasn’t professional. Yes, I get, in this age of no political correctness and and rise of the food fight mentality, people love a good cat fight. We’re talking about science here and scientific method. There is no room for name-calling and bomb throwing. These are two people with terminal degrees, PhD and MD are the end of the line, Eagle scout, “the gold standard baby”. A lot of us expect more from our doctors, be they medical or PhD. Make your case with facts. Let facts refute facts. Let better science rigor refute lessor scientific rigor. Don’t do food fights.

    • sten bjorsell

      Walt, I reply briefly down here instead on your question above: “…The 24hr fasting, which is to say, the 21:3 fasting I tolerate near perfectly. I’d say most days perfectly, rarely though, it is a real struggle come about early to mid afternoon. How did you find four to five days? Again, thank you!”
      Fasting more than a meal can be hard with SAD eating moving to 24 hrs is really hard. But on a keto diet things become easy! The lower the carbs and proteins are on the keto, the easier it is, as it is then closer to burning body fat, the “absolute” ketogenic diet which fasting is. (Still only 95% fats as our phagocytes then are working overtime to scavenge old inflammations and broken cells for both fats and proteins to either reuse or burn during the imposed nutrient shortage. Great helpers that everyone of us have free, not yet taxable anywhere!)
      The 1st fasting day is hardest, the 2nd is easier the more ketogenic the pre-fasting diet is.
      After then fasting is “nothing”, just keep going and on a little high at the same time. So do not be impressed by 5 days! Main difficulty is to complete 24 hours and go into and through the 2nd day, with grade of difficulty as just explained. Have to leave it there for now. Cheers and good luck !

      • Thanks Sten. I do take one liberty with the fast portion of the day. Let’s say the fast begins at 8pm (or 6pm or 7pm), about 12 hours later I do have coffee. Both Drs Fung and Mosley say a splash of milk or cream is acceptable. I use 2 mini-moos, 10 cal from fat each. I, generally have 2 coffees in the morning. I have the coffees 8 hours before supper. I figure since fat essentially doesn’t raise insulin I am being faithful to the 21-ness of the 21:3 fast. Again, with the exception of whatever sugar was in the cheese cake, no sugar or refined carbs have crossed my lips in about, if not over, 2 months. I asked that question to take a gauge on what I could expect doing a full on water fast.

        Is it reasonable to assume fasting, esp water/KD fasting will raise my EE to essentially what Mifflin suggests it should be? And would that be permanently or just for the duration of the fast?

        • sten bjorsell

          I think you misunderstand. It is not fasting or KD per se that increases metabolism or resting EE. It is insulin levels and food supply that sets up resting EE. Eat a lot and it goes up and body temperature goes up, but you gain weight. Fast for a few days and EE goes DOWN, UNTIL you are fat burning adapted = keto adapted, which translates in that the ‘high insulin imposed’ nutrient shortage disappears and body fat can be burnt, again. Low insulin means no more blockage to burn body fat. That is the “holy grail of weight loss” . It may take up to 3 days before the insulin is low enough to allow first all the glycogen and then fat out of the liver and then start burning rest of the fat stores, then quickly normalizing resting metabolism, because the nutrient shortage is then over!
          Your metabolism will then stay normal as long as there is fat left to burn! The massively obese man that water fasted for over a year (world record 382 days) was asked after about 6 month if he never was hungry. His response was “Never hungry with this much fat left”, grabbing some of his stomach flesh. The take home about resting metabolism is really that it takes less than 3 days water fasting for most of us to restore normal resting metabolism because it is all about getting “idling insulin levels” low enough. Once we get warm again it is done!
          Once there, stick to fasting or a keto diet if you want to continue to lose weight. Starting with a keto diet helps because it makes the initial transition to fasting much easier. But if you fast longer than 3-4 days, increase the days a session at a time to get used to re-feeding problems. Add gray sea salt to water and drink black tea or coffee during fasts and use lots of salted bone broth the last days before finishing a longer fast. I would still not fast more than 5 days in a row as the liver needs food fats to flush itself clean.

          • Is grey sea salt a different animal than normal sea salt? I mean aside from it being ‘collected by hand using traditional Celtic methods and wooden tools’? Isn’t it just NaCl plus minerals?

        • On day 2 of water only fast! I woke up at 1:30 with very cold feet. Within the hour, while not feeling warm, they were no longer cold. I weighed myself this morning and that weight gain I had mentioned as been removed. Allow me to clarify my question. Yes, I understand as we lose weight our BMR or total energy requirement drops, being there is less of us to maintain. If we lose 10lbs or 100lbs our BMR will be proportionately lower and be expected to remain there. My understanding from all the research papers and blogs on ‘damaged metabolism’ or adaptive themogenesis, is that one’s BMR drops perhaps 300cal – 600cal /day below that which is expected. See the K Hall Biggest Loser/J Fung rebuttal. The point that Dr Fung makes and, as I recall, Dr Hall makes, is that there is no adaptive thermogenesis with fasting. That’s good, if you started fasting at 450lbs and continued for 13 months at 180lbs you’d have a BMR that pretty much equals that which Mifflin St. Jeor predicts for a person of that height, age, and gender. What I did, in this case, was not fast for the bulk of my weight loss regiment. My expectation then is, at least at this point any decline greater than what should be expected – going forward – should be arrested. My question is will fasting result in my BMR returning to what would be predicted based upon my new weight, and would that be ONLY in the context of a continued fasting or would that reset a “broken” metabolism where the conclusion of these actual studies is that the ‘below predicted’ BMR is likely permanent. They don’t, however, test in the context of fasting. So that would be a ‘requires further study’. When I was taught how to describe research efforts they should always contain the ‘followup next essential question’ to be researched. Hopefully that question reflect a pivotal point, rather than a silly one.

          • Valerie

            Hi Walt,

            I’ve read a few of your comments, and you seem absolutely confident that fasting raise (or at least doesn’t lower) metabolism.

            I would suggest you do some research on this question outside of Fung’s writting. From my own searches, it seems that most studies on fasting do show a reduction in metablism, while a few show an increase.

            Also, after a massive weight loss like yours (congrats!), I would expect your insulin sensitivity to have greatly improved. In fact, I don’t think your current metabolism issues are related to insulin, but rather to leptin. Your leptin level has probably crashed with all that fat loss. Unfortunately, besides eating a whole lot and/or regaining weight, I don’t how a weight-reduced person can raise their leptin level. 🙁

            I share your frustration at all those weight-loss promises that don’t materialize. Best of luck to you (and us all).

          • Hi Valerie. Thanks for your reply. Frankly, I see that issue you mentioned as one of the ‘magic happens here’ moments in Dr Fung’s thesis. I’ve asked for clarification on how is it a SAD or a high carb or a whatever would lower metabolism below what should be expected but, magically, not a fast. I don’t know enough to call him out on that. I believe, however that his arch nemesis, Dr Hall, agrees on that point, I think. So, no, I am not absolutely convinced of anything. I do know I lost over 100lbs on a CRaP diet, which the lectures and book seem to declare impossible and my feet weren’t freezing once but I did hit the predicted plateaus and behaved as Dr Fung predicted one would. This before I ever head of Jason Fung. So, OK, next! So on this 24hr fast that everyone seems to rave about (Mosley, Fung, Eat-Stop-Eat, leangains) I’d give that a shot. As far as liptin goes, I am not especially hungry and I don’t ‘cheat’. Liptin is satietion, ghrelin is hunger, if I recall correctly. After I eat, even 500cal I feel pretty ‘full’. Come what would be dinnertime I am aware I am blowing through an otherwise scheduled meal but I am not gnawing on the furniture. I am coming up on the second missed supper and I am aware my stomach is empty but I am not salivating uncontrollably.

            On raising leptin, neither do I, another magic happens here as far as fasting. That, actually, is the thrust of my question re: will a fast restore normal predicted caloric budgets to actual homeostasis.

            Frankly, at this point 1500 cal/day is feast baby feast! That used to be considered starvation diet or perhaps that was just hyperbole by, well, certain authors. If I up my calories to the point my feet aren’t freezing and I, as a result, blow up like a helium balloon, I’ll be more than frustrated. This is why I am feeling really wedged right now. In flight mechanics, this is called coffin corner. The aircraft, a jet, can’t go higher and it can’t go slower without fear of entering a spin, which would be really really bad. you

          • SomePerson

            So, I know this comment thread is from months ago, but I’m wondering if you ever got your answer Walt. You appear to have been a very similar trajectory to me, but only about 5-6 months ahead and I wondered if you figured things out. I’m pretty sure I’ve figured them out for myself, but time will be the ultimate arbiter of that in the end. I figure you probably ended up landing somewhere similar to myself, but was curious.

    • Hi again Walt,

      I’m replying higher up your thread because the comments are getting too narrow on my screen. I hope you see this reply.

      Cold by not hungry?

      1- Worth getting your thyroid tested, I guess.

      2- It reminds me of a video by a guy named Jim McCarter who went on a ketogenic diet for a year. He felt mostly fine except for the cold. He used to swim a lot but now dreaded getting in the water, as it felt much colder than before. In his talk, he says that eating (a lot) more salt solved the problem. I hope I’m remebering correctly. Here is a link:

      As to increasing long-term metabolism through fasting … I’m sorry to say, but that seems highly unlikely to me. I have not seen such a thing described anywhere. On the bright side, slow metabolism, if you are comfortable the low food intake, is probably good for longevity.

      • Hi Val, yep I had thyroid added to the list as I go for my 90 day A1C, CMP etc this week. Yes, I too am skeptical. I asked Fung on here, on email, I asked Megan, if she is ghost writing for him nothing. I have officially started day three of water only fast 3 hours ago. I just got out of 30mins in a Jacuzzi to warm up my insides. Yes, not hungry cold hands and esp feet. Stuff I’ve read points to ‘oh that’s brown adiapatic fat diverting blood from extremities to get glucose. Also, I maybe should have dropped Atoravastatin. I, likely have no triglicerides now. I mean, I get it, I don’t expect him to do free medical advice. That would be unethical without history and maybe even illegal. So I am trying, and think very successful in not asking me questions, as opposed to clarifying seemingly contradictory parts of the book, some of which I or you mentioned. If nothing else he can test drive the clarifications then put them in the 2nd edition of OC and make special mention for the one this fall, reversing diabetes. I think the 2018 book is curing world hunger or achieving world peace. More later!

        • I haven’t found any studies or useful discussions of how to increase EE. I think, when the time comes, eat more and move more combined with eating whole/real foods and IF (IF to control insulin and fat gain and get HGH boost). Check out how Sam Feltham experimented on himself by eating 5700 cals/day with LCHF for 21 days and then again HC

          I think the EE boost from fasting comes from noradrenalin released – so it’s temporary. However lean muscle mass gained due to HGH should be persistent if exercising. I think loosing fat/weight is a polar opposite goal to increasing metabolism or fitness and that no one has a good model for basal metabolism.Insulin resistance is part of the equation and helps control the Body Set Weight, but I’m sure there is a lot more going on. Again, eating extra food would probably nudge the body to use it.

          You’ve come a long way. Congrats on losing 120 lbs and getting down to 190 lbs. Wow.

          • Thanks Rob! Yeah, as of this morning, 187, by the end of the week, sub 185 perhaps. I kind of tend to agree with you on the EE normalization. It is unfortunate I didn’t even know of Dr Fung’s existence until the bulk of my weight loss had occurred. As for exercising, I did that, like a fiend which may or may not have helped for 10 months. I built up to 660 cal / day 6 days/week. There were the occasional weeks where, yes, I did lose 3lbs (2 from the 1,000 cal/day deficit off of BMR*1.2) plus 1lb from cardio. What’s interesting is the first 20lbs were for simply removing myself from a stressful situation (work plus 2+hr commute/day). This, likely, is a testament to the power of cortisol. My, purely academic, question then is, how much of that weight loss (100+lbs) was from removing stressors and my body realizing I was, in fact, overweight. If that is the case, or to the extent it is, there may be no or fewer penalty points (BMR significantly below that which is predicted). It’s a shame people can’t reasonably get an answer to, “ok, what is it really?”. My biggest fear and the genesis of my questions is the very real concern I’ll have to take persistent heroic measures to keep the weight from returning. In the case of BL, I doubt anybody wants to, having gone from 400+lbs to 200lbs, return to 400+lbs. In other words, OK, 160lbs, sedentary life style, my caloric budget is 1800cals/day, as opposed to finding out the hard way, no, it’s really 1,000cal/day.

        • In regards to increasing metabolism, I meant when you have reached your target or are ready to take a break from loosing weight (ie stop being calorie negative). Then you can try experimenting with excess calories combined with LCHF and IF to control fat gain and increase EE.

          Sam Feltham didn’t mention metabolic increases on his 5700 kcal/day LCHF diet, but did mention a decrease in waist size and a small increase in weight. (I’d post a link but my comment wouldn’t publish so I removed it)

        • Interesting news. I’ll try to get the blood work done tomorrow. I am winding down on day 4 of the water only fast. Yesterday I lost .8lbs. This is really nice as the scale is not bouncing all over the place weight wise. .8lbs is 2800 cal, given a lb is 3500. So, is it far to assume that my REE is currently 2333cal as that times 1.2 (sedentary lifestyle) is 2800? On page 241, Dr Fung describes Adrenalin as, at 48 hrs, increasing metabolic rate by 3.6% and by day 4 by 14%. My ketostrips arrived and I am at the dark purple part. What is a tad humorous is when I would attempt Atkins, it’s not clear to me there was actually any purple on the strip not created via wishful thinking. This was unmistakable. My feet are still intermittently cold but not freezing. Temp has climbed but is still below 97 degrees F. My FBG this afternoon was 70. It has been slowly drifting down over the last 4 days. What will be interesting is in 24 hrs, 5 days, it stabilizes at 70 or maybe climbs a bit as 70 is the floor of normal range. So what does it mean to drop below 70?

          • Concentrated ketones can also be a sign you aren’t drinking enough water.

            Dr Fung says FBS frequently goes down to the 50’s during multiday fasting.

            I believe ketones replace some of the glucose in the blood. You are probably good as long as you are feeling fine, in ketosis, and not on any medication that affects blood sugar.

            I’m sure you already know, but just in case, remember to break your fast gently. Perhaps with a few nuts or small serving of soup roughly a half hour before eating a normal meal. For me, the first meal runs through very quickly…

      • Hi walt- I understand exactly what you are saying. I have run the gambit of all of these methods and despair to see any progress. It occurred to me that I should also try and heal my thyroid since my temp was 94.6 for years. I see what you mean about getting less and less to eat and then where does it end? I put on weight due to hormone issues / menopause/ and couldnt lose a pound. Low carb didnt work, fat fast didnt work, I have now been doing IF 22 hours fasts everyday with a 2 hour meal window. Since phinney stated he thought to lose weight we should eat 800 calories I did that for awhile and still didnt lose much. I started taking nascent iodine about 6 months ago and finally now my temp is up to 98.3 and while still doing IF and tracking my foods and staying under 1000 calories , Iam suddenly starving all the time. I was eating around 2pm and now cant last past 10:30am. I just decided to up my calories to about 1400 since i even wake up in the night with my tummy rumbling and I had read That 1000 calories is less than a 1 year old needs. I would love a test to determine exactly what my metabolism burns at rest daily . That is the 64,000 dollar question. though. Its a guessing game for me and I do measure my blood sugar since my fastings were to high for my liking 125, and i knew that had to come down for health and weightloss. Now they are about 100 so i know iam going in the right direction. From my readings alot of us are deficient in iodine and i have to say i feel much better since taking that than the meds my old doctor gave me years ago. I dont do doctors anymore.

    • The way I read, it Dr. Fung says that if you have insulin resistance from some combination of eating too many carbs, eating too often, bad genetics, etc. you will have high insulin levels 24 hrs/day. However, one of the first things that happens when you stop eating is that insulin goes down. Operating on the premise that constant high insulin levels cause insulin resistance, insulin levels should gradually go down. Cells will become more insulin sensitive.

      Keep in mind that this is a THEORY. Dr. Fung read that LCHF and fasting can cause some hormonal changes, he tried it in patients (who had T2D and likely failed conventional treatments) and it worked. Surprisingly well. I think he’s on to something here, and these blog posts are about figuring out how this intervention helps some people. SOME people.

      The body is complicated. Hormones are insanely complicated. Some people do well on calorie restriction (though IMHO they are a minority), some people do well on LCHF, some people need fasting with LCHF. Dr. Fung has a post about how obesity is multimodal, with many causes and many solutions. Some people like high carb, others like ketogenic. I’m losing weight doing 5:2 and nothing else. But then again my hormones are different than yours.

      I also wonder if you’re doing too much? I think it’s a good idea to find the “sweet spot” where you’re losing weight or maintaining a good weight without overly stressing your body. Maybe it’s cortisol, maybe it’s other hormones too, but it seems that if we push our bodies too far they will respond in unexpected and negative ways. Haven’t you already lost 100 lbs? That’s amazing, and I hope that you’ll consider just trying to maintain that.

      • Hi Robin, I am going to respond as if you were replying to my post. Yes, I have read Dr Fung’s OC twice and done selective re-reads for clarification on certain points. Further, I’ve viewed his 6 part YouTube series on Aeitiology of Obesity at least twice plus, perhaps most of, his one off casts. Actually it’s 120 or so at this point. No, I have a few more to go. I think the overly stressing part is what I am resolving, off meds, lower bp, lower fbg. You could start at the top of this blog post or go back to some prior blog posts if you are interested in my ‘journey’. And why wouldn’t you be, after all it’s me we’re talking about! 😉 Just kidding Robin, seemed like a good place to do that. To paraphrase Matt Daemon, I’ve been scienceing the sh&t out of this for some time. So, I’ve gone from CRaP (very successful btw) but all diets fail, to a modified Taylor/Mosley/Fung(IF) diet and given that later has caused wicked freezing feet, it was surmised that was due to IR and the best way to remove IR is continuous water fasting. Review the posts by Sten, above and below here. He gave me the encouragement to try this out. I will likely start to unwind this tomorrow night, perhaps a supper of Hormel Turkey Ronis, fat and protein, 17 are 70 cals. Drinking liquid bone marrow is not terribly appetizing to me.

        • Walt- Are you reading labels? I bet there is corn syrup in the hormel product. Its in everything nowadays. Corn syrup is the only thing that shoots my sugar up to 200. Bad stuff..

          • Hi Seebrina, nope. 0 carbs, 0 sugars, only fat and protein.

  26. Awesome critique Jason. Best I’ve read. Well done. Keep up the good work. You’re smarter than most scientists.

  27. Jeez, the above commenters disappointed about the good doctor’s passionate response to Kevin Hall’s paper remind me of those special snowflakes on a college campus that, upon hearing a disagreeable word, seek out their little safe space and curl up with their teddy bear while sucking on their thumb.

    Dr. Fung sees the damage done by diabetes everyday and as an obviously caring individual he gets mad when someone implies it is okay to continue what is an apparently harmful course of action. The internet is awash with subjective tales–anecdotes–of people having cured their T2 diabetes by avoiding refined carbohydrates or even avoiding carbs altogether. No one should accept an anecdote as a universal truth but surely no reasonable person would dismiss out of hand such a preponderance of information. And THAT, to me, is Kevin Hall’s real sin.

    Dr. Hall’s paper was an analysis of statistical data, not anecdotes, but his conclusion is the opposite of what any “reasonable” person would decide faced with all the anecdotes and all the published statistical data. Dr. Fung is correct to angrily point out out that Dr. Hall finished his paper with an unsupported opinion.

    As for Dr. Fung’s annoyance that reporters would take an opinion piece as fact, well, that’s what reporters do. Since the bad ol’ days of the Viet Nam War I have viewed the “profession” of journalism, and its practioners, with contempt. I always assume that, like a politician, a reporter is either outright lying or, at best, is twisting the information to fit his or her narrative.

  28. All this stuff is resolved pretty simply by adding another groups. For starters it’s always a must in modern studies to add a control group. More than that for this purpose you should keep people on SAD to compare the two diets. It’s simply badly designed study that’s all. You can’t make bad science and expect correct results

  29. Brian Gurwitz

    Dr. Fung,

    Why do you assume from the evidence in this study the SAD diet weight loss would stop or slow, but weight loss on the isocaloric KD would continue?

    Look forward to seeing you speak this weekend in San Diego.

  30. sten bjorsell

    Early up Dr Jason wrote this:
    “When patients embarked on their run in phase, they were switched to a 2700 calorie/day high sugar high carb diet, meant to replicate the Standard American Diet (SAD) that caused the obesity epidemic. Nobody actually believes that this is a healthy diet, and nobody believes it should cause fat loss. But it did. Why? Anybody who has done research knows why. It’s the effect of going into a study and knowing that people are testing you. It’s a universal effect. That’s the precise reason why we have run-in phases. To establish a proper study baseline when people know they are being watched.”

    There may be a much simpler reason for the weight loss in the SAD group. Not only 300 calories but also snacking would disappear completely during the SAD part of the study. Snacking is probably the “Fat super-charger” today, not even (?) included in the assumed 3,000 standard calories. Snacking also widely promoted, including for our kids that today go hungry too quickly on 3 meals per day because too much fat taken out of the food…
    Our grand parents always advised “no food between meals” !

  31. […] roligt exempel på det här är när Jason Fung i sin text som är publicerad både på hans sida och på Kostdoktorns engelska sida kritiserar studien för att man i den skriver […]

    • sten bjorsell

      I recommend you to practice reading and writing more English so you can see and comment on what we already have written here. Swedish does not fit in here, really. Cheers!

  32. Dr. Fung, I am essentially in agreement with you on this. I have one question, though. By what mechanism or process would the participants lose weight initially on the SAD? I mean, with the math course analogy, it’s how much homework and study, etc. being consciously done. Regarding the Initial SAD consumption in this experiment, do you mean that the initial 2700 calories they consumed was possibly fewer calories than they typically consumed before the experiment began, resulting in the initial weight loss? Or that they actually consumed fewer than the 2700 calories they were assigned to eat?

    • sten bjorsell

      The typical diet was 3,000 calories, 10% reduction. Link to study is above. Also see my comment about pre-study snacks never accounted for just above here, and the important comment by Jason July 21 above.

  33. Dr Fung shows his anger and frustration in this post – I’m angry as well. My poor mum suffered horribly the last 10 years of her life with diabetes. The doctors advised her to “eat low fat, count calories, eat every 2 hours so your blood sugars don’t fall, barley sugar candies when you feel dizzy, ooh you’re not controlling your diabetes, naughty-naughty let’s up your insulin”…. she lived off wholewheat low fat cardboard crackers, cottage cheese, low fat yoghurt, low fat 99% fat free chemical frankenfoods, margarine etc and as a result hungry..always hungry..chewing her arm off practically in hunger. If only she were around today her life could have been very different.

  34. (Another) Moment of clarity (request) please. OC pg 239. phase 3 Gluconeogenesis 24-48 hrs after feeding; Insulin levels begin (I assume ‘being’ was a typo) to fall. The breakdown of glycogen releases glucose and from amino acids and glycerol. In non-diabetic persons, glucose levels fall but remain in the normal range.

    What happens to diabetic persons? Is that the insulin reaction where they have to eat a Snickers bar or take glucose tabs? Even though last summer I was declared diabetic and last dec my summer a1c went from 8.5 to 5.8. I’ve never experienced, to my knowledge, an insulin reaction. I can say yesterday my fbg was 86 and today it was 79. Is that noise or a significant drop? I am guessing the former as that would be 82 +/- 3 or about a 3.5%. But then that is also on a pure H2O 48hrs. TIA

    • sten bjorsell

      Please extract some clarity from Dr Fung’s excellent article about high morning glucose and the causes of it here:
      It takes time for a liver full of sugar and fat to become “normal”. High insulin can give low FBG while a little lower insulin can give very FBG and normalized insulin and insulin sensitivity eventually gives good FBG. Read his article carefully!

      • Sten,

        I have a friend that follows a very strict LCHF diet. Her highest blood sugar is her fasting 1st am reading typically between 115-130. After meals she is well under 115. She has done several 5 day fasts and her 1st am readings drop to 80-90. She has also gotten her insulin tested and during those fasts she is at 1 or below. It would see to me, that if it is dawn phenomenon during her long fasts her 1st am readings would be high, since low insulin lets the liver dump. She/we can’t figure out why her morning numbers are so high when she is eating but during a long fast they drop. Any thoughts?

        • sten bjorsell

          Sue, your question is very interesting and should really be put to Dr Fung but I think he is busy preparing for a big event right now. Impressive getting the fasting insulin down to 1! What would her fasting insulin be when eating regularly and obtaining the 115-130 ? If it is a lot higher then maybe it has to be kept down longer to “fully reset” ? Maybe it depends on age and regulation reduces as we age? Here a possible plan to try: Set up 4x 5 day fasts over 8 weeks and check FBG in eating weeks to see if there is a trend towards improved FBG. If a gradual improvement is seen, that’s probably the answer. If not, maybe some nutrients like minerals/vitamins are required to rebuild the insulin regulation system to function fully, then try replacing during eating weeks. The Autopaghy taking place during the fasts should in any case have positive cleaning effect on the whole body, meaning nothing but unwanted stuff lost during the fasts. My guesses only!

          • Wow, thank you so much Sten! And I have posed this question to Dr. Fung but certainly understand he is unable to answer every question. And yes, so happy that her fasting insulin is so very, very low!! She is having a hard time finding a doctor who is willing to do all the tests that she wants, when she wants them! 🙁 I believe all that you have said is what I am thinking, it’s nice to see you’re in agreement with me. LOL .

            I surely appreciate your response. CHEERS!

        • Hi Sue,

          My understanding is that the liver dumps its glucose (glycogen) in the blood in response to cortisol (and other counter-regulatory hormones). The higher the glycogen level in the liver, the more glucose it dumps in the blood in response to the same hormonal input.

          A low-carb diet will reduce the day-to-day glycogen content of the liver, but a fast will lower it even more. Hence, your friend can see her dawn phenomenon when she eats, but not when she fasts.

          Bill Lagakos had a series of blog posts (on caloriesproper) where he suggested that eating more in the morning, and less at night, would improve morning glucose reading in people with dawn phenomenon.

          • Thank you Valerie! All of that makes sense! I’ll take a look at Bill Lagakos…. thank you so much for your good advise!

      • Hi Sten, I have read that but where I was going, asking, is his clause ‘for non-diabetics FBG lowers but status in the normal range”. Normal I assume is 70->100. The other day I was in the 80’s high 70’s. This evening it was 70 on the nose. I understand HIGH fbg, I was asking about low. For a diabetic, which I’d like to think I am not at this point, low fbg precipitates an insulin reaction forcing the snickers bar or glucose tabs. So I believe, that was his point by specifying for non-diabetics it will drop but stay normal.

        • I should clarify. I do not test fbg in the morning, I test it before, what would otherwise be, supper. Consequently, what happens when I am asleep is not a factor here, plus it talks about rising fbs.

        • sten bjorsell

          When one eat a low carb diet BG of 70 (3.9 mml/l) or lower is usually compensated by higher ketones meaning it is not a “diabetic blood sugar fall”. I have that reading most of the times when I eat once a day. Without the hypoglycemic symptoms like feeling dizzy or very tired, low BG is compensated and no need to eat anything. Keep up the IF and you will be fine!
          To keep you there, read about the dangers of eating 3 high carb meals per day and what high FBG does for cardiovascular health, or “how I became sick”. Well highlighted in this short study abstract from 2011:

          High fructose (the other part of sugar) does no such direct damage, instead it slowly worsens same postprandial glucose spikes time after time by fattening the liver. Sugar, the two sided sword.

        • Sten, you are a steely-eyed master at this! This is day 5 of a water only fast. I just had my blood draw which includes thyroid. I am dropping like a rock. No euphoria..yet. Odd thing, yesterday ketostik was registering 16 (far right), this morning, a color pane or two below that reading. I am dropping roughly a pound per day. Intermittently my feet are still very cold, especially if my legs are crossed. If I put it on the ground it immediately warms up. Do or did you experience that? I am within spitting distance of declaring victory. I believe for the foreseeable future I will follow your 2:5 fasting model. I should be mid normal weight band (BMI wise) by mid August. What I am thinking is in 3 months at next A1C test. I am preparing for this one to be low to mid 6, on the US scale.

          • Sorry, next A1C should tell the tale, NIDDM wise.

          • sten bjorsell

            Walt, Jason Fung is the master! Your full body heat will return I am sure! Thanks for your good example of 2:5 , this other way!

          • Well, I’d feel more like that but I finally put together a list of all my questions asked from various blog entries that were merely clarification type, things that seemingly contradict other statements, and emailed them. Yeah, I am certain he is a busy guy what with a 2 yr or really long waiting list for patients and speaking engagements. So I finally thought maybe that’s Megan’s role as she owns the LDP. Finally I sent another one asking if there was some policy about dialogs with non-patients. I could have sworn I was clear. So, where you’ve answered many/most you get the gold star. I did rationalize through how could my ketostik reading be 16 (burning fat big time) yet still have cold feet? Doesn’t burning fat preclude IR? I thought burning fat was the opposite of resistance. So why is it with a 16 level fat burn extremities are still cold? Had yours, if you had issues, clear up w/i the first 5 days? What I was kind of hoping for is if I have an off day (IF) with 500cal) that my body would capture the other 1500 through ketosis. I think logically that makes sense. May not be accurate, ergo clarification questions. That phrase, btw, can from “The Martian” movie. “Be advised, RIch Parnell is a steely-eyed missile man”. Great line!

          • Someone, I think it was either Ann or Valerie, asked me to post my last A1C results that I was preparing myself for being higher than I wanted. It was 5.6. FBG was 69, considered low. By the end of the day when I tested it here, it was 78, normal. I am aiming for my next A1C in Oct, to be in the 4’s. They didn’t test, Cholesterol or triglycerides, which strikes me as odd.

          • seebrina

            Walt- Have you considered your circulation? Not sure you mentioned your activites but I sit at a desk to work and am cold. As soon as I do a few laps Iam much warmer.

        • Sten, measured fbg this afternoon, 78. So I am am feeling feeling better about any precipitous drop.

          • sten bjorsell

            Hi Walt! It may take some time for circulation to be fully restored in the feet. When fasting with physical activity both metabolism and circulation are increased. Let us know if any difference after 2 days with 30 minutes walks! I had cold feet every night going to bed before my fasts and cannot recall when it stopped. I am walking 30 mins per day since. Now kicking away the blanket from feet almost immediately after going to bed. Sten

          • Sten, interesting use of ‘two days’. Here’s why. I broken fast last Thursday as Fri is ‘date night’ here and I wanted to be sure there were no ill-effects from a Friday night meal. Both Thursday and Friday night meals were around 1,500 calories, enough to take me out of ketosis. I resume my fasting after Friday night’s meal. Friday night, I believe my feet were fine, and not too bad on Saturday night. Sunday night (last night) was bad even with wool socks on. Over the weekend I was periodically checking my keto output which remained zero or imperceptible close to zero. However, at some point Sunday night/early Monday morning my feet became toasty warm. Monday morning I was ‘full on’ throwing ketones. Dr Fung states the ketosis stage is 2-3 days after a fast starts, Fri night to Sat night, Sat night to Sunday night is two days. That begs an entirely different question. Does / when / should the body stay in ketosis to augment the calories consumed by other means, such as orally? Does the fact I or anyone) dropped out of ketosis with a sub TDEE diet indicate a metabolic issue? A related question is in a non-fasting diet how is fat burned if not via ketosis? Sunday afternoon my blood pressure was 110/70 with a 55 pulse. It had entered throttle-back mode. Why that vs burning fat? Will that change going forward? Where you’ve been doing this for awhile now, do you seamlessly go in and out of ketosis or do you still ramp up and ramp down such that that two day window is always tough?

          • monica

            Hi Walt, I am guessing here: if you ate enough fat during Thu-Fri, you might stay in ketosis. If so, maybe your body will adapt to fasting without the ups and downs. Thanks for your posts, and I am looking forward to my Walt-inspired fasts, starting tomorrow.

  35. gracielou

    I say “follow the money” with respect to this John Hall character. He was probably influenced by big pharma, the food industry, and/or the diet industry.

    You may be thinking, “but wait, he works for the National Institutes on Health, a government agency. He’s objective.”

    The fact is special interest groups lobby government agencies and government employees all the time, and succeed. That’s how ketchup got classified as a vegetable (for public school lunch programs) , why GMO foods aren’t labeled, and why companies who label their dairy products free of bovine growth hormone were almost banned from doing so. The list goes on and on.

    Big pharma doesn’t make money when people are healthy and don’t need any medication. The food companies and the sugar industry that manufacture processed food, soda and sugary foods lose money if people eat primarily whole, unprocessed, low- or non-sugar foods. The diet industry doesn’t make any money when people are healthy and normal weight.

    This whole theory of insulin resistance causing obesity and being able to it and diabetes by eating a healthy diet (low/no sugar, whole unprocessed foods) diet and intermittent fasting is really bad for profits.

    It’s been proven that lobbyists even write bills that congress presents on the floor. I wouldn’t be surprised if a special interest group wrote or contributed to his paper.

  36. rick mccarthy

    Thanks Dr. Fung for showing me how to eliminate the problems of Type 2 diabetes. I have an unrelated question to put to the good Doctor. Is it possible that the rise in obesity is due to the increase in CO2 in the atmosphere

  37. Keep hammering them Dr. Fung, I am as angry as you are about the perversion of science for political ends. People are dying. People are losing limbs and it is because people like Dr. Hall are given a pass by the polite people.

  38. If no one calls out the misinterpretation and misrepresentation of scientific studies, then the funding for expanded studies of these results will not be available.

    The forked tongue interpretation of results leads to a fork in the road by which the lemmings will follow each other off a nutritional cliff. Ancel Keys, much?

  39. Dr. Fung, I think you were too nice. We trust researchers to check their personal biases when doing science. We trust them with our lives.

  40. It is refreshing to listen to the voice of educated reason in Dr. Fung as he is yelling, “The emperor has no clothes.” I’m diabetic and taking the path he has outlined in his book, generous blog and website. If some of you want to argue that the buttons on the emperor’s jacket are not shiny enough, go ahead. I need the voice of reason to reverse my diabetes and it is all starting to make sense because of Dr. Fung’s research and care to take the time to inform us. Don’t dwell on the nay sayers Dr. Fung they are still mad the earth is not flat.

  41. Look at the results in light of DR PANDAS WORK on time restricted feeding. Many people eat 15 or.more hours a day. Fewer eat 12 hours and few eat 9 and fewer still restrict eating to 5 or 6 hours. So in the artificial lab time restrictions of Halls study maybe the Time restrictions are the driving factor.

  42. Increased EE for a little over a week and then back to baseline… that’s not going to do anything long term. The benefits of keto has nothing to do with increased EE. The end.

  43. Can you or we do better? Yes, call it intermittent fasting or time restricted feeding!
    Use to Salk institute app from doctor Panda and collectively create your own study of one. Or many.
    Test time of eating window
    Macro nutrients

  44. You know what would be interesting? Do a 4 week run in phase on a strict keto diet, then an actual experiment with the standard American diet. I have a hypothesis at what the results would be and wonder how Kevin Hall could spin that?

  45. ultimately, who cares?
    YOU can’T change people, even DR. FUNG can’T change people
    people have to want to change themselves – THEN they can change

    all we can do is show those who want change, how to accomplish it
    we must BE the change we want to see in the world

    we must DO lc/hf, and do it well
    when we drop weight, get healthy, look better, feel better, and get OFF of prescriptions. . .
    those who WANT change, will come to us and ask how they can too.
    THEN we are preaching to the right people

    the carbohydrate industrial complex,
    and pharmaceutical industrial complexes are so massive, with so much momentum, power, and funded
    we can’t overcome them from the top down, or policy change level,
    it won’t work

    the only way to attack them is from grass roots, ‘vote with our dollar’, approach
    when we quit buying the “FEED” (notice i didn’t say “FOOD”) that they stock on the shelves,
    and profits shift from big food, to local farmer . . . will they feel any heat

    quit offering answers to those who aren’t asking questions

    be employing LC/HF ourselves, . . .
    THAT is how we get them to ASK THE QUESTIONS!!

    only truth can defeat lies
    and sometimes it isn’t done through debate,
    but by evidence

    now go make an omelette and bacon to fuel the evidence for others to see

  46. I am looking forward to more on fasting time restrictions and macro nutrient research.

    Maybe restricted feeding research will show 8 hours on SAD junk food is better than 15 hours of keto or vegan or palio? Maybe 8 hour feeding blunts differences in macro nutrient?

  47. […] to Kill the Insulin Hypothesis with Pure Spin – Dr. Jason Fung’s response to Dr. Hall: Here’s $5, Kevin Hall, go buy yourself a clue – Dr. Michael Eades’ response to Dr. Hall: Contradictions and Cognitive Dissonance: The […]

  48. […] piece by Anthony Colpo, the excellent analysis by Stephan Guyenet, to the cringe worthy blog of Jason Fung. Indeed, many noses were put out of joint and so dismayed were some, that the rebuttals transcended […]

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