The Evidence for Caloric Restriction

posted in: Calories, Health and Nutrition | 113

There are many people, highly educated and believing themselves intelligent, that say that all diets come down to calories. So, any diet that works automatically comes down to cutting calories. It seems to be a fallback position of many academics and researchers and others who tend not to live in the real world. They say ‘This diet (Paleo, Low Carb, Whole Food etc) works because it creates a ‘caloric deficit’. That is, reducing the calories you eat will create a caloric deficit. They often invoke the old Calories In Calories Out rule.

Change in Body Fat = Calorie Intake – Calorie Output. Yes. This is true. This is, of course, analogous to the crowded bar. Change in Bar Crowd = People In – People Out. But so what? Who cares?

The first law of Thermodynamics is always true, but completely irrelevant to human health. Yes, if Calories In is more than Calories Out then you will gain fat. But if you eat more Calories, you will burn more calories. If you eat less calories, you will burn less. So there is no overall change in body fatness. Just like the bar – if more people come in, but more people leave, then there is no change.

The problem is that people now make the entirely unwarranted assumption that Calorie Output remains stable so that reducing calories intake (food) automatically results in loss of body fat. This is why I see tables like this, that are liked by so many. As I’ve written about many times, this is utterly false. Basal metabolism may increase or decrease up to 40%.

But this false belief results in the strategy that I call Caloric Reduction as Primary (CRaP). So many people believe that simply reducing calorie intake is a reasonable strategy of weight loss. They think that hormonal changes (mostly insulin and insulin resistance) created by intermittent fasting or paleo or ketogenic diets are irrelevant. For them, it’s all about calorie intake. But, we believe in evidence based medicine. So, where is the evidence that reducing calorie intake as the primary strategy results in long term meaningful weight loss?

People assume that it is a scientifically proven fact that reducing ‘Calories In’ will cause long term body fat loss. Experimentally, this is simple. Take some people. Randomize them. Give some of them calorie restriction. Watch them lose weight and live happily ever after. The others who continue with their usual diet don’t lose weight. Simple.

Can somebody please point out those studies to me? We’ve recommended the ‘Eat Less, Move More’ strategy for almost half a century. Where are all these studies? Oh, right. They all conclusively show that CRaP does NOT produce long term weight loss. Let’s look at some of these studies. Especially the randomized controlled ones.

The TODAY study was a study of diabetics using medication (metformin)  with or without lifestyle changes. This was primarily the calorie-deficit approach so beloved by academic physicians. The main study showed that this CRaP method produced no clinical benefits in diabetes management. What about weight loss?

Let’s see. At the beginning of the study, the average Body Mass Index of the lifestyle group was 34. After 5 years of dietary counselling to reduce calories, the average BMI was…….. 34. Nice job, guys. Glad you spent the last 5 years of your life counting calories?

The Diabetes Prevention Program was another randomized lifestyle study that aimed to prevent diabetes, which was, in fact successful. But the question here is about weight loss.

With intensive counselling to reduce intake of calories weight loss was terrific (7kg). At first. In the long term, not so much. In a pattern familiar to every person who has ever dieted, the weight starts to regain despite continued compliance to the diet. Within a few years, there is only a small difference in weight (2 kg or less than 5 pounds) and by the end of the study, there is virtually no difference.

Body weight decreases nicely within the first 6-12 months, but thereafter shows steady weight regain.

What about non-diabetics? Let’s look at the Women’s Health Initiative. Almost 50,000 women were randomized into the trial and given instructions to reduce their fat intake. This is the largest and most important nutrition study ever done of the low fat caloric restriction diet intervention.

Over 7 years, women reduced their daily calorie intake by 361 calories per day. They reduced their percentage of calories from fat and increased their carbs. They also increased their daily exercise by 10%

Sounds like they followed the ‘Eat Less, Move More’ advice to a tee. So they must have lost lots of weight and thanked their academic doctors profusely as they slipped into their skin-tight yoga pants. 

Yeah, not really. Here’s what happened to weight loss. Against the comparison group that followed their usual diet, there was an initial weight loss, followed by the now familiar weight plateau and then eventual regain. There were no improvements in waist circumference either.

There are many who complain that this was not specifically a weight loss study. It’s always easy to nitpick study design after the fact. But the fact remains that two groups were randomized. One received dietary counselling to reduce calories, specifically from fat. As a result, calories were reduced. Isn’t it all about calories?

Let’s also use a little common sense here. Is this WHI result so unbelievable? Hundreds of millions of people have followed a calorie reduced diet. I certainly have tried it. What’s our personal experience? Pretty much exactly like the WHI study proved.

Also, it is important to note that women did, in fact, stick to their calorie reduced diet. Yet the weight regain still happened. BUT it wasn’t because of non compliance. This is often ignored, because physicians giving the dietary advice want desperately to believe that people fail on their diets because they didn’t follow it. They simply cannot face the super-obvious but highly inconvenient truth staring them in the face. If these women followed the diet, but still failed to lose weight – the problem is the DIET, and not the PATIENT. Doctors cannot play their favourite game of ‘Blame the Victim’.

So, every single diet works by reducing calorie intake, right? But every single study of reducing calorie intake shows no benefit in weight loss. How does that work? Where is this magical fairyland where reducing caloric intake automatically causes long term weight loss? How can all diets be successful only to the extent that they reduce caloric intake, when reducing caloric intake is proven to NOT cause weight loss?

We profess to live in an age of evidence based medicine. But this only seems to apply to everything that is not the accepted conventional wisdom. The status quo always gets a free pass. Where is the evidence that cutting calories causes weight loss? Bueller? Bueller?

113 Responses

  1. One of the reasons the ketogenic diet works is because it reduces hunger, most likely due to low insulin levels and the effect of ketones. Has nothing to do with reducing calories, which is an effect of the diet. That is, you don’t say to yourself, “I’m going to reduce calories by eating a ketogenic diet.” Similarly, I find intermittent fasting does something similar, probably for many of the same reasons. But again, reducing calories is an effect of the diet. I find something similar with eating breakfast. If I eat breakfast, I eat more over the day. Always, unless I skip lunch. Why do I eat more just by eating breakfast? It has nothing to do with trying to consciously eat more. I just simply do. (And sometimes I want to eat more, such as if I’ve fasted a lot previously or will fast a lot after the day I eat breakfast — Dr. Fung’s feast and fast idea.)

    The whole CICO idea is a fiasco that has lead to indescribable damage.

    • Patrice Herbert

      > One of the reasons the ketogenic diet works is because it reduces hunger, most likely due to low insulin levels and the effect of ketones. Has nothing to do with reducing calories, which is an effect of the diet.

      This should be etch in stone and framed in blinking lights, Las Vegas style.

      • Except that it does. It is still about the 1st law of thermodynamics and calories in/calories out except that there is a hormonal signalling going on which is controlling fat/carb burning and metabolic rate. Once insulin is low and the body can access body fat, it will burn this to meet body needs, if it cannot access body fat and calories in is low, it will reduce metabolic rate. Still 1st law of thermodynamics.

  2. It amazes me to no end that those who insist on the first law of Thermodynamics apply it in a wrong way in this case, yet accuse the followers of insulin theory of dismissing basic science.

    Calories come in, the body adjusts its metabolism to account for any change from the required level of energy – slows it down to defense from the lack of calories or speeds it up to remain in the balance when there is an excess. The first law is perfectly in place, what’s the problem? This effect is demonstrated in so many studies so many times, who really dismisses basic science?

    • Vadym Graifer, simple, if people admit that the metabolism can vary its speed based on energy intake, then there won’t be any logical reason to victim blame the obese anymore for their personal failings in neurotic calorie-counting. Can’t have that now.

    • What are these studies?

    • As far as I know, the First Law of Thermodynamics only works in *closed* systems. The human body is *not* a closed system.
      I really don’t understand why people use this when they refer to human bodies.

      (Happily fasting away, nearing my 4th month and never listening to any ‘objective scientist’ ever again, who talk about calorie restriction, low fat and the benefits of carbs. (And neither to poor informed veterinarians who keep advising carbs in food for our carnivorous cats and dogs and who keep wondering why diabetes, cancer and tooth decay are on the rise in their patients / our pets as well).

      • Ron Hunter

        There is a ton of money from food and beverage companies that have a highly vested interest in maintaining the CICO model. After all, it’s not the crap they’re selling, it’s all those people that simply need to eat less and move more.

        I voted for Obama, but his wife did not help in this regard.

        • Ron,
          It is true the food industry does make a lot of money but they also try to be responsive to current trends. They are in the business of making money but if we want something different they will provide it, so they can earn a profit. They started offering lots of gluten free alternatives. They now even have cauliflower mash available somewhere, I saw an ad for it! And back in the day when low fat was all the rage what did the food industry do but find ways to give us low fat anything and everything possible. Yes they added sugar to make it taste good but no one minded that one bit back then b/c fat was the villain not sugar. They are going to have a bit tougher time offering whole food items rather than processed in order to keep up with low sugar/low carb demand. The blame really lies elsewhere.

      • There is a formulation of the law of thermodynamics for open system. From Wikipedia:

        First law of thermodynamics: When energy passes, as work, as heat, or with matter, into or out from a system, the system’s internal energy changes in accord with the law of conservation of energy. Equivalently, perpetual motion machines of the first kind are impossible.

        In other words, if the neat heat flow over the control boundary of a system is non-zero, the internal energy of the system must change.

        • Another way to look at this is an analogy to a business. Profit equals money in minus money out (analogous to the first law of thermodynamics). Simply cutting costs (reducing calories) will only work in the short-term. Eventually, you can only cut so much and for so long before the business will eventually need to change tactics or go under.

      • Chris Hastings

        Great reply! My dog has been on a raw carnivorous diet with IF for years now and he does great with it!

    • The 1st law of Thermodynamics is immutable. It says that Energy can be neither created nor destroyed simply changed from one form or another. This applies everywhere including Human Beings and the sooner we accept that as a fact the better. That is not to say that the Calorie in/out model is correct because that ignores hormonal signalling. That signalling controls the body’s response to the food that is coming in. The body’s hormonal response will govern how the body will satisfy energy needs either by burning fat or reducing metabolism but either way, the first law is not broken.

      When we understand this we can see that first we have to reduce insulin which then allows the body to burn fat. This fat will come from food if there are sufficient calories coming in and fat from fat cells if there is not.

  3. You don’t get a day off, Dr. Bueller! We need you.

  4. I think we need to coin a new phrase for this Slight Hole in Thermogenic (SHiT) theory. What do you think Dr. Fung, may we kick it up a notch?

  5. Can anyone point me to a forum where I can find out how effective it is to do a 36-hour fast one day a week and a 24-hour fast one day a week? I’m just learning about intermittent fasting and am trying to figure out what will work (mostly for weight loss, but also for inflammation from RA).

    • Dana, has a wealth of resources and lots of Dr. Fungs videos on intermittent fasting.

      My RA was eased by wheat elimination. The Wheat Belly book explains why – Gliadin, a protein in Gluten, causes intestinal permeability, allowing the contents to leak in to your system where it accumulates in joints. I had terrible knee and ankle joint pain, which was relieved within 3-4 weeks of giving up wheat.

  6. “How can all diets be successful only to the extent that they reduce caloric intake, when reducing caloric intake is proven to NOT cause weight loss?”

    ****So then how do body builders get into single digit BF% numbers? Many do this on high carb diets. They must lower their caloric intake.

    • Because bodybuilders go through a building phase (high protein) to build muscle, then a cutting phase (low carb) to lose fat. You should know this, Fred. If that’s your real name.

    • Fred,

      The experience of bodybuilders actually supports Dr. Fungs point in that:

      – Caloric deficit will eventually lead to fat loss but it is not sustainable due to the hungry and miserable syndrome, which includes testosterone drops, lethargy, etc which is widely documented close to contests and was the subject of a recent study

      – As bodybuilidng coach Layne Norton has written about extensively, an approach which maintains calories out is critical, which in his case is extremely slow calorie reduction from an extremely high metabolic rate..not something most normal people are in a position to do

      – Fitness model and physique people use a variety of supplements that artificially raise calories out during the cutting phase, specifically clenbuterol and thyroid hormone and so called “dry” anabolics, again not something most can do long-term and even if so, it stresses the need to maintain calories out

      – Many of the people who get ultra-lean for a contest (especially women it seems) balloon up massively after the contest. I have seen this at my gym in particular. Yes, I know they ate too much, but in a state of extreme leanness and associated low metabolism, a little can be too much

      • Widely documented that it only happens in case studies unter a certain bodyfat percentage. If you take the case studies, most people would KILL for their normal appearance that these people can hold without much of the problems described. it is when you go Sub-Seven that things get wonky.

  7. No one in the mainstream medical community believes that fat people stick to CRaP diets. They honestly believe that it stops working because lazy, impulsive fat people can’t control themselves and can’t be trusted. So they believe that the sharp downward slope is when fat people are being Good Fatties, and that it goes back up because fat people are cheating and lying about what they ate.

    I have heard this from MANY doctors. I’d bring in food journals and I’d be accused of lying.

    I feel pretty vindicated after a few months of IF’ing. Not only am I 100% certain that I was never cheating, I know have the unassailable proof that I have a willpower of steel. 🙂 (I’m currently on my 3rd day of an extended fast.) My willpower was not deficient. My character was not deficient. Their science was bad. Their plan set me up to fail and get sicker.

    It makes me want to punch some people in the face.

    Thanks, Dr. Fung.

    • RIchard Fish

      So true. At my last medical check, my doctor reviewed my progress since I discovered The Obesity Code and self-incorporated fasting into my T2D therapy. Progress: glucose normalized to 90-day average 87; 90 pounds lost; blood pressure reduced to acceptable levels. I’m healing! Doc then agreed to stop metformin. I felt very good: armed with Dr Fung’s wisdom, I had reversed my T2D and I continue to address insulin resistance. Then, on the way out of the office, my doctor stopped, and with a knowing wink, said, “Fasting is reducing your calorie intake, right?” Argh!!! He did not understand! Blame was fully transferred back on to my shoulders!

      Sometimes, we who are very sick with this epidemic, life-threatening situation, are justified in feeling very alone! Shame on the conventional medical “wisdom”!

      A few fortunate individuals — on our own — seek and find Dr. Fung, a few other similar professionals seeking to understand the real causes … and each other. We heal. We come to understand that we are not totally alone. Shame is replaced by knowledge, pride, satisfaction, renewed health … and gratitude.

      You said it correctly Maura … thank you Dr. Fung!

      • Thank you for your supportive comments. I seem to be living in a medical backwater and your experience and determination are inspiring.

      • Richard, Marilyn I am not a member of the diabetes epidemic but I certainly appreciate reading reports like yours. I recently sent my daughter-in-law a copy of The Obesity Code. When I asked where she had heard about it she said it was referred to on a Facebook group, Physician Moms, I think. She said it was having an effect on patient treatment. She is an osteopathic physician of whom I am very proud.
        I too thank Dr. Fung , every day.

      • Yea, Richard!

    • Unfortunately your experience is not unusual. Six years ago I was told that my “cholesterol” was too high and I had to lower it by taking a statin. The doctor handed me a write-up that said I needed to lower my consumption of cholesterol containing foods. I am not making this up. After six months and following advice from the AHA and ADA websites, things were worse.

      I started learning about lipoproteins, how the lipid system actually works, and how to buy an NMR lipoprofile. I started counting carbs, not calories. My weight went down 10 lbs to what it was when I was 30 years old. I am now 70. Eventually I went Paleo, and then finally keto.

      The lipoprofile changes were huge and persistent. I am talking 80% drop in TG’s and a 60% jump in HDL-C. The type B LDL concentration was below the measurement threshold. What this all means is subject to debate, but how to control a lipid profile is not.

      There are two shocking things about my lipid profile: (1) there is no drug that will do this, and it is not because the drug companies have not tried, and (2) my doctor’s reaction to the outcome.

      He looked down at the floor and said we would have to go with the test results, which I paid for in addition to the insurance premiums. He had no comment or even questions relating to (1) above, none. It was time to see the next patient. He had failed to sell statins so it was on to the next sucker. If he did not know that he looked like a fool, he must have gotten his medical degree from one of those mail order places.

      My opinion at this point is that the healthcare system should more properly be referred to as the medical business. It is not scientific or evidence driven and the so-called standard of care is determined by corrupt entities – AHA, ADA, etc. You would think that the insurance companies would rebel. But, in actuality, the status quo is maintained and whenever the claims for the chronic diseases that result from this sea of corruption goes up, the premiums are just raised to make the claims payments. In fact, one of the biggest lies of the 20th and 21st centuries is that the medical/insurance business wants to reduce the cost of healthcare. They don’t pay. You always pay in disease and premiums or taxes depending on your system of so-called healthcare.

      Basically, when it comes to chronic disease, it is do it yourself medicine. Submit to the present medical business and you are going to be converted into a diseased, dependable cash flow. You doctor is either too stupid to realize this, corrupt, or afraid of being sued if you he does not follow the standard of care established by the associated corrupt quasi-government organizations.

      I used to think more government control would fix this. I was wrong. Take a look at the UK just to offer one example. Just maybe the internet will fix it, but it takes a lot of work on the part of any individual.

      • Samuel you nailed it!! You called it the Medical Business. So sad for the patient. We are on our own.

    • Hear, hear, Maura. I also feel rage that for decades while I struggled to diet as advised (low fat high carb) I was made to feel that my continued failure was because I was lazy, stupid, ignorant, fat, waste of space, greedy, weak, no willpower. Now, after just over a year of limiting carbs and upping natural fats I find it so easy to IF whenever I want, and usually eat lunch/dinner or just dinner most days. It was the advice that was wrong, not me.

    • Because in 99% of cases, that is the truth. When you actually put people in a metabolic ward including a chamber, measure their RMR, measure every single thing they eat, these things just NEVER happen.

      Once you lift restrictions minimally, let people go and report their own diets, uh, for some reason they DO happen. Now if you take the same people and weigh everything they eat, you often get to a more than 40-50% higher number than they report.
      This is the experience in basically every single study done in that way. That is why most people do it.

  8. Deborah Hart

    The Biggest Loser was CICO or “eat less and exercise more” on steroids, with the same abysmal long-term results!

    • No. The biggest looser is an onslaught of insanity, not an intelligent regimen. The thing is always: Short term approaches have short term results, long term results need long term approaches. And the biggest looser is a show that throws these people on their asses. And if they are NOT helped long term, they will absolutely get back to their old habits because they are the sickest of the obese, because otherwise they wouldn’t get on the show. Their hypothalami are so damaged from their old habits and their overall drive is so insanely strong that the environment NEEDS to provide proper clues, otherwise they will be lost.

    • Every single Biggest Loser winner ended up gaining the weight back despite counting calories

  9. Deborah Hart

    I’m an obese, insulin-resistant yo yo dieter, but I never stayed compliant to the diet during the regain phase. It was like an overwhelming compulsion to eat as much of the foods I had been denying myself on the diet as possible, while suffering from temporary amnesia about what I was doing to my body. IF is helping me regain control.

    • Deborah,

      This phenomenon is dealt with at length in Dr. Fung’s book The Obestity Code. In the regain phase you’re not bingeing because your willpower suddenly, magically evaporated. It’s all about hormonal imbalance and your brain’s idea of its “set weight”. When we lose weight but don’t fix the hormonal problem, which is what happens on a classical low calorie diet, our bodies fight to get back to whatever they think our set weight is. Some of this they do by slowing the metabolism, and some by compelling us to eat out of control and unrelated to actual hunger. We do this because of hormonal imbalance, not because we’re lazy or, the more recently fashionable explanation, because of our emotional relationship with food.

      The same thing, albeit from the opposite perspective, is seen in slim healthy people with good hormonal balance who, in overfeeding studies (i.e. where you don’t actually LET them eat less over the study period), gain almost no weight. Their bodies ramp up the metabolism to burn all the extra calories to maintain their (healthy) set weight.

      • You see, the fun fact of that hormonal thing? Insulin is actually the good guy in that whole scenario, because it actually stimulates POMC neurons and thus leads to LESS hunger. The neuroscience part many ignore…

      • seebrina

        Also as stated in Taubes ‘Why we get fat”, We eat more because we are fatter not the other way around. Children in growth spurts eat substantially more and fill out and grow taller. They are eating more because the body demands it Does anyone accuse them of being weak gluttons? Its hormone driven. Even rats who are food restricted will stop moving at all to keep their set point and stay fat. So the fatter we get the more the body needs to maintain that. I truly believe it has a lot to do with all the hormones in food, drink and environment of today. 100 years ago you never saw 600lb people, there may have been obese people but not the extent of today.

    • Deborah, you WILL regain control. There is so much POWER in fasting.

  10. Dominic Proctor

    Great information. I saw your interview on Utube about intermittent fasting. I am not exercising and I reorganised my desk to a standing version and I am still losing weight. I hope to buy your book over Easter. Thanks a lot for fighting the confirmation bias of the establishment.

  11. I have found myself by eating less carbs I am simply less hungry. Its the spikes in blood glucose that then crashes one’s blood glucose levels that makes you want to eat (snack) between meals. I’ve done multi-day fasts in the past but I’m going to be more gentler on myself and just do 2 x 36 hour fasts / week. So finish eating in the evening wake the following day coffee and lots and lots of fluids = water thru out the day and an early bedtime (without exercise today) and break my fast tomorrow around noon-ish. So I’ll be doing effectively a 5 and 2 diet. I could go longer but consistency is more important where I keep this up over the longer term and put my T2DM into remission.. FYI My BMI is in the 24’s range & I sense I’m on the cusp of T2DM remission having already lost 52 lbs from diagnosis weight about 3 years ago..

  12. I tried intermittent fasting, the 16/8 kind. I did it for about 3 months. I lost a few pounds early on. Then I stalled and began regaining. I had better luck with a low carb diet, even had one stretch of spontaneous weight loss. But then I stalled and the weight started to creep back on. It was motivating to lose weight by restricting carbs; very demotivating to be regaining while avoiding carbs. Without the motivation of success, compliance became hard for me. Unfortunately, I’ve regained most of the weight I lost from low carbing. I still regularly switch back to that style of eating in the hope that the miracle of spontaneous weight loss will return. Unfortunately it eludes me.

    It does seem that there is an escalation that happens to some who go this route: try paleo, it works, for awhile. Then up the ante, go with nutritional ketosis. It works for awhile. Then up the ante, and combine fasting with nutritional ketosis. When that isn’t enough, what then?

    • Stan: try full on fasting for 2 days/wk. Maybe once every season (3) months go on a week long water fast. Even Dr Fung says in Obesity Code, something to the effect that every strategy ultimately fails. Do not fall into a routine, or when you detect it not working, switch off. The body is very good at adapting. You need to stay ahead of it.

    • sten bjorsell

      Stan, See what Rustybeth says below: “It’s the insulin, stupid. Turn off (high) insulin, burn fat, lose weight. ”
      Over a certain age, dependent on genes and how much carb exposure we have had, base insulin is simply too high. Extend fasting to minimum 2 days. I stopped eating Sunday night. Blood glucose on Monday morning was around 6.5, as I was prediabetic at the time. Monday evening it was probably 5.5. Next morning maybe 5.0 and when I eventually finished fasting it was 3.2. But it took 4 days to “empty the liver” as I think Dr Jason says. I needed a long fast like that to push down or “reset” the high insulin. Today, nearly a year after a few similar fastings, my morning blood sugar is 4.7. Normal. Not overweight any more.
      BTW water fasting, with bone broths with added K+Na sea salt starting day 3. Black sugar-free coffee as much as I liked, and a half a lemon in 2 litres of water freely as the lemon seem to quench both thirst and potential cravings. My fasting insulin was down to 5.3 from over 7 after three 5-day fasts over three weeks.

  13. Rustybeth

    It’s the insulin, stupid. Turn off (high) insulin, burn fat, lose weight. I believe Covert Bailey coined the phrase “release the grease.” Seriously, folks, hormones control EVERYTHING, even fat loss.

  14. I can only wonder if in 100 years there will be a pill that really works. Like live on Twinkies but remember to take this pill that causes several other ailments.
    Researchers in Sweden are planning the clinical trial of a new treatment for nonalcoholic fatty liver disease and type 2 diabetes which harnesses liver cells’ own ability to burn accumulated fats. sweden trial

  15. What does it mean that people were “coached to reduce calories”? How were the subjects monitored or held accountable? Were they given precise weighed foods? Also, it looks like they lost weight initially and then rebound…could this be because they stopped eating in a deficit?

    • In research funded by NIH, Dr Taylor’s work, and, presumably, others the subjects were hospitalized to control out of scope eating or exercising.

  16. My question is how do you know that the WHI particpants stuck to their diet over time? I agree most diets fail to keep the weight off after an initial drop…and I would say that’s (a) because most diets are really hard to stick with for the longer term and (b) your thyroid will down regulate your metabolism. When you think about it…if the calorie theory in the pure sense was true and you stayed in the exact deficit (eg 500 per day) for ever you would waste to nothing. Our hormones have a big role to play in our metabolism and our overall energy balance. Many simplistically blame just insulin but forget about glucagon, cortisol, adrenaline, T3, ghrelin and leptin. Also the hormones of the hypothalamus and pituitary. Biochemistry is complicated. I must say it’s really hard to come to firm conclusions about this stuff but it won’t stop me trying!

    • Stephen T

      Craig, I don’t know how typical I am, but I have no difficulty sticking to a low-carb diet because the natual fat content of what I eat means I’m not hungry and good, tasty food is available to me. I stay at my set weight with little effort and I’m in control of my appetite and not the other way around. I felt a huge surge of mental and physical energy when I abandoned the low-fat nonsense and started eating fat freely. A slight tremor in my left hand disappeared and my skin improved. I can’t explain this but I’ll take it.

      The benefits are so obvious to me that I’m not remotely tempted to go back to the ‘official’ way of eating.

      • Hi Stephen although I don’t eat low carb myself I too would find it easy to do. There’s no question on the face of it lots of people benefit. What I am trying to reconcile is how this happens. I have read many different articles/blogs/research in an attempt to reach my own conclusions but can’t quite get there. I can’t resist trying to link back to biochemistry which I studied…although a while back. At a macro level we eat carbs protein and fat. All have energy (i don’t believe in the calorie theory as the numbers are estimates at best). Some of this energy is lost during absorption, some is lost due to thermic affect of food – protein has the highest- and the rest has to go somewhere. Some ends up in the urine. Proteins can end up as muscle, enzymes, hormones etc. Fats can be stored or broken down for energy production either via ketones or TCA cycle. Carbs can be stored as glycogen, used for energy via TCA cycle (aerobic) or lactate (anaerobic). Once glycogen is full they can be converted to fat. I understand that more energy is consumed the heavier you are (in particular lean muscle mass) but how else do we burn more? We would have to somehow be increasing flux through TCA to produce more ATP and exhale more CO2 and water vapour….or be building more compounds in the body which would lead to weight gain. If anyone can help me complete the puzzle I am all ears. In the meantime I will just keep on reading…and reading

    • I think one factor is this. First 500cal/day do not stay at the same net cals/day. As you lose weight your BMR drops. What research has found and even Dr Fung has reported, metabolic adaptation occurs lowering your BMR below that which Mifflin St Jeor equation predicts. This means you’d have to routinely accurately measure BMR and drop 500cal from that number.

  17. No, I am not trolling. But by way of honesty in references, a graph with missing axis range is meaningless. I refer to the Diabetes Prevention, first graph. Now, I have seen this elsewhere when the X-axis was present and ranged. I just wanted to point that out from the perspective of copy editing.

  18. I’ve said this before, many times. There is a ‘dear leader’ thing going on here too. I was diabetic, a1c of 8.5. I did tons of research, “scienced the shit out of it” when the dietitian I was sent to had an opening stmt of “by the time one is diagnosed Diabetic 80% of their beta cells have already died. It is a progressive chronic disease”. Ergo, tons of research where I found study results from early New Castle Magnetic Imaging Centre research conducted by Dr Roy Taylor on reversing diabetes. This was perhaps a year before I even heard of Dr Fung. I found the social app My Fitness Pal, logged everything I ate and every calorie I burned and told the app I wanted to lose 2lbs/wk. Guess what? I did. Not just the 2lbs/wk but generally another 1/2 to 1 lb from the exercising. In about a year I dropped over 100lbs and my 8.5 a1c became 5.8 and labeled by the software printing the results “NOT DIABETIC”. Dr Taylor, in his talk, “Reversing the Irreversible Type 2 Diabetes and You” agrees with Dr Fung that exercise has little effect on weight loss programs. However, he does say it is important to keep the weight off (more on this in a bit). However, definition of terms is important, on graphs and this anecdote. When people talk about exercise, do they mean “Biggest Loser” exercise or window shopping walks? Somebody once said, of fitness center patrons, if your elliptical or treadmill work out is sufficiently light to be able to read a book, you aren’t exercising. My workout quickly ramped up to -700cal/hr or more. It was a sweat-fest. The other patrons, they were walking on a flat surface maybe 1-2 mph, burning maybe 35cal/hr per MFP. Radically different eh? What I was doing was interval training type exercise varying at between a 5deg and 8deg incline at 3.6mph. It wasn’t a constant 700cal, that was weight dependent. But it was aggressive.
    The weight does want to return, perhaps if I had known about IF then it would have a better ‘going forward’ outcome Currently I am doing IF in the form of a 18-6 IF, sometimes 20-4 IF everyday with rare exception. My FBG is mid 80’s to mid 90’s.

    My only point in this post is be careful about scoffing at the ‘willfully ignorant’ and elevating IF and Dr Fung as ‘the one true god’. CRaP and eat less, move more DOES work. Sure, I had plateaus but I also lost over 100lbs. The issue is, IMHO, how to keep it off which is where, according to Dr Taylor, exercise is important and reducing/eliminating simple carbohydrates is critical.

    To Stan: try full on fasting for 2 days/wk. Maybe once every season (3) months go on a week long water fast. Even Dr Fung says in Obesity Code, something to the effect that every strategy ultimately fails. Do not fall into a routine, or when you detect it not working, switch off. The body is very good at adapting. You need to stay ahead of it.

    • By way of a very sad footnote, when I presented that dietitian with the work of Dr Taylor and research aggregation of Dr Fung, her response was, “I am too busy to read through that stuff”. That, I presumed was her chosen profession…WTF? I interpreted that as her way of saying “I was wrong” “fake news” “false gods”. No, it was her being willfully ignorant.

      • Funny thing Walt I wrote to my mother’s doctor about the cholesterol hypothesis being wrong with heaps of links to back me up to try and stop her prescribing statins but she said exactly the same thing as your dietician!

        • And that makes my head want to explode ala Drew Carey Show. I simply don’t understand that. Having said that though Craig, I think, again, based on what I’ve read statins are great, the lower your LDL the better. As tough as this is to say outloud, there is no such thing as too much statin??? ewwww. LDL, apparently, is just that bad.

          • Stephen T

            Walt, my brother was losing his memory on statins. The benefits are tiny. According to Dr Mark Porter’s summary in The Times, the NNT for statins is 400. That means one patient in 400 benefits marginally. A decent diet has a far better NNT of 60. Many people suffer side effects, sometimes serious.

            The cholesterol theory is a money making machine, but I believe it’s nonsense. The countries with the highest rates of cholesterol have the lowest rates of heart disease, France Switzerland and Germany being three of many examples. A theory that produces the opposite result to that predicted is just plain wrong. The only thing keeping this nonsense going is the money it generates.

            • In America of 137,000 people, in 541 hospitals, who’d had a heart attack, 78% had below average cholesterol. (American Heart Journal, 2009.)

    • see my comment below – which I must have posted simultaneously with you.
      Intermittent (IF) Fasting even combined with LCHF will ultimately fail then if we do the same method and way of eating daily then?
      We will always need to shake things up then, the ways we IF, perhaps even straying from LCHF – all to keep the body guessing!

    • Christopher Hamilton

      I’m going to play the antagonist here, I think I see a flaw in your presumption and would like to explore.
      You claim that crap diets work because you lost 100lbs, 100lbs may seem like a victory to you but all my adult life I have been able to lose that much before regaining it again, but have you been able to return to your previous eating habits and not spring back to your previous weight? The question isn’t, for me at least, “did the scale change?” but rather “did the body fat storage rate change?”
      I know that sounds farcical to some reading this who still believe in weight loss, but hear me out. I have reached an epiphany about my weight. If I lose pounds today that come back tomorrow then my plan has failed. The goal is not to lose weight. The goal is to stop storing so much fat.
      I have cico’d since I was 16. At the age of 17 I had gone from 360lbs to 315lbs, then within six months or so I was back up, over the years I have yoyo’d between 320 and 420. I am 31 now. Losing 100 pounds is pretty easy comma control calorie intake and add in some exercise and it will drop. It takes about a month-and-a-half for me. The problem is that that weight has never stayed off. It always comes back. I plateau somewhere around 320lbs and then, regardless of how much willpower or intervention from friends or exercise I include into my regimen, the weight always comes back. Well, perhaps it would be fair to say the weight always had come back, that is until I found Dr. Fung.
      Long story short, I IF’d over a couple of months and lost 70lbs. My fasting blood sugar dropped to 80 and my persistently high blood pressure (200/120 avg.) dropped to hovering around 120/80.
      I posted recently in the Facebook group about my sudden inability to get back on my fasting regimen after a break. I’m still struggling with that a little bit, an issue which I know is hormonal, but it’s important to note that I have not regaind the weight. And it hasn’t been because of my stellar eating choices either. A local pizza buffet restaurant has a loyalty card, buy 10 get one free, I’m on my third card. Everyday this week I have gone to a buffet and eaten my fill. I intend get back on track next week, that isn’t the important part, but I have literally been eating anything I want over the past month or so. Pizza, a whole package of Reese’s Peanut Butter Cups four times last week, carbs and sugar and bread and anything else I desired.
      This morning I am putting on the same size pants that I was wearing when I stopped fasting, and my weight has not gone back up. I have had the nurse at work measure my blood pressure and it hasn’t gone back up. I am usually warmer than my coworkers (sweating in rooms where other people are comfortable) and my mental acuity is up (I’m breakthrough ideas to solve problems none of us have seen in months), both signs of ramped up metabolism.
      After hundreds of failed crap diets, and I say failed because they did not cause my body to lose fat, for the first time something has worked to keep weight off long term.
      I have no Illusions about being able to keep up this level of eating over it extended period of time, eventually the persistently High insulin levels would repeat the process that created the fat in the first place, but I think my experience with fasting has been profound in that the weight that was lost has not returned after stopping.
      It’s also important to note that I have done that without exercise changes, the way I work I don’t have time, I schedule every minute of my weekdays and I do not make it to the gym.
      So I’ve come to the hypothesis that crap diets, while they do present success by way of the metric “losing weight”, fail to address the problem of stored fat.
      All of that being said, you claim that a crap diet worked for you, I’m curious what would happen if you spent a month eating to excess? Would the weight spring back? Or would your body ramp up your metabolism to compensate?

  19. If all diets fail (and I totally agree with this) and if the body gets used to a particular method ie: 16/8 or OMAD, while eating LCHF – will this also ultimately fail? What to do then…shake it up?

    • Yes, Obesity Code pg 264 under “What to Expect” “You probably eventually experience a weight loss plateau…”. That’s his complaint on the others. So yes, you assumption is correct. “shake it up”. Fung advises “change your fasting regiment, dietary requirements or both…”.

      I was trying to avoid having to look it up but I remembered about where it was. For that matter, go on Weight Watchers. I mention that as a study found of all the diets out there, Atkins worked the best for initial weight loss, even Fung reports this, as I recall. However, that same study found Weight Watchers best for maintaining weight loss. So, even staying on IF 18-6 or 20-4 everyday w/low carb. Try what I suggested to Stephen, every 3 months do a week long water fast, switch to 5-2…as you said, ‘shake it up’.

      In a different section of the book, he states, “all diets fail and all diets work”. Does IF work better? I don’t know. I think the take away is, do everything you can to eliminate insulin resistance. I think Dr Taylor makes some interesting observations. 1) since the 80’s the entire population’s weight distribution (a normal curve btw) has shifted up. In other words, the left ‘tail’ of the curve is higher now than in the 80’s. The other observation was everybody has a weight ‘set point’ above which they become diabetic. Now, the interesting thing is, couple that with the seminal work of Dr Joseph Kraft who proves diabetes can be accurately forecast/diagnosed upwards of a decade before it shows in a FBG test. There are diabetics in the under weight category, normal weight category, overweight category as well as obese category. Everybody has their own weight set point for diabetes. Fung’s primary thesis is that everything starts with insulin resistance. Just because you are thin or normal BMI, doesn’t mean you aren’t diabetic but don’t know it yet. (glucose tolerance test vs FBG or A1C). The other thing is body weight has a set point. If you’ve lost 20lbs or 200lbs the goal is to maintain that loss until your metabolism accepts it as the new normal.

    • I believe there is an important distinction to make here. Diet will fail if it’s a diet – as in, limited term weight loss drive that must be abandoned at some point, because it’s too restricting, difficult to stick to etc. If, however, it’s a method that repairs one’s hormonal balance and allows an enjoyable lifestyle while maintaining lowered weight – why would that fail?

      Not to be theoretical, let me cite my experience. Low carb for a couple of years, lost 25 points, blood sugar still sat high with A1C at 7.3 despite max Metformin dose. Then found Intermittent Fasting, dropped 50 pounds over 8 months, eliminated Metformin, yet A1C dropped to 5.9. Now, here comes the most pertinent part:

      Switched to a maintenance mode since then, remaining in it for about 5 months with relaxed carb intake and only occasional fasting. Both menu and fasting regimen are highly enjoyable, take absolutely no effort to stick to (in fact, when I fast I do so because I like how it makes me feel). My weight remains stable, and yesterday my latest A1C test came back at 5.7 – again, without medication, without strict dieting requiring strong will (or any will whatsoever). Foods that are no-no (highly processed oversweetened junk) also require no effort to stay away – not only don’t I have cravings for them, they are outright disgusting to me. I don’t see how and why this could fail.

      • Ron Hunter

        My experience is quite similar to yours. I write on Quora and call it this a “way of eating” or a “lifestyle.” For most folks I suspect even if you lose substantial weight that the carbohydrate intolerance remains. I had bariatric surgery and lost a ton of weight and just about had my diabetes under control but following (the horrible) advice of the American Diabetes Association started eating carb and found weight and A1C slowly increasing til I was back at 9.0.

      • Vadym, IF is a diet. It will stall (fail) too. Ron, Atkins is designed to be a lifestyle change as well. People focus on phase one (Induction) but there are many more. It, too, fails.

        I think the distinction you both refer to is managing/reversing diabetes and losing weight and keeping it off. In the fomer case, yes, reduced/eliminated ingestion of simple carbs is important as a lifestyle change. Defeating your body’s desire to return to its original weight is a different mechanism. Read the books and other literature, don’t simply pray at the alter of Fung, if that’s what people are really doing.

        • Walt,

          please explain why it will fail. I am at my ideal weight – what do you mean by “it will stall?” It “stalled” because I stopped active weight loss drive after having achieved the goal. I stay at it with no creep-up and no effort, despite not doing a lot of fasting anymore and despite an increase of carb intake (still staying on a low side but anywhere close to keto). So what is going ti happen in your view, how the failure is going to manifest itself?

          The theory advanced here is that lowering insulin resistance/insulin levels IS that mechanism. By all signs, this is what I have achieved. What makes you think this mechanism is not engaged in my case?

          Please don’t suggest that I “read the books and other literature.” Believe me, I have – a lot. And I am far from praying at anyone’s altar. This kind of assumptions is unwarranted.

          • In your last paragraph you end the discussion with don’t suggest I read the book. If you look at a post or two above I give the exact page number in the book where the author, the venerable Dr Jason Fung, that so many here worship, said it. I am not saying that, in any way to denigrate Dr Fung. Over the last, more than a, year I’ve yet to see him engage in any discussion on here, even with direct questions or requests for clarification are made. So really, apparently, you (and others) need to pay Diet Doctor to get direct answers from the good doctor. If you HAVE the book it’s on page 264 under the b head of “WHAT TO EXPECT”. The alter comment was not directed at you, it was an observation that people have when they choose a ‘Messiah” be it for Juicing, fasting, running, publishing performance numbers for electronic equipment. It is the relinquishing of common sense and critical thinking to wholly place their faith in someone else. Anyone else. There are places where he, in his book(s) seemingly contradicts himself yet offers no disambiguation. Little fault on his part, he has an apparently highly successful practice (with a 2 yr waiting list). Look at the praise being heaped on here here. don’t get defensive, you weren’t under attack.

          • OK, let’s leave that whole part about blind following and worshipping aside if you don’t mind. I prefer to discuss the topic at hand.

            With additional information I provided, do you still think my weight loss is unsustainable and my body will try to regain the weight? No slightest signs of that appeared in 5 months since I switched to maintenance mode, and that corresponds with the theory that LCHF+IF, through the mechanism of lowering insulin resistance, changed my set weight point. If there are aspects that I missed and should be on a lookout for, could you outline them?

          • Vadym, again, I am not a Dr and I am in no position to challenge Dr Fung. The best I can do is give personal anacdotal evidence of my story, i.e. losing substantial weight via a so-called CRaP diet and repeating what Dr Fung has written in his books, as I have both, read both (multiple times) trying to do my own disambiguation. To answer you question, you’ll know if / when it stops working or shows signs of not working as well. To this specific point, and I will quote, “You’ll probably eventually experience a weight loss plateau. Changing either your fasting or dietary regiment, or both, may help…Changing the fasting protocol is often what’s required to break through a plateau”. Pg 264, Obesity Code.

            Honestly, if you’ve found something that works for you, absolutely congratulations. I, and I am sure everyone else, is happy for you and maybe even a tad envious.

          • Vadym. Yes, it may have been different if, what, 18-24 months ago I had come across Dr Fung’s webinars…maybe. I am doing IF now and have been since last fall. Initially, I continued to lose weight. I found the gym I joined gets seriously overcrowded after the first of the year, with NY resolutioners. This lasts essentially through the end of Feb. So, unlike the prior yr, I stopped going from just before Christmas to March 1. It is THERE that I started gaining weight. How much of that is me being careless w/carbs and how much is to maintain weight loss I really do need to exercise? Dr Taylor agrees with Dr Fung re: exercise not valuable for weight loss but IS valuable for on-going maint. I also wanted to see if the strict adherence to IF was necessary and, frankly, was no/low carbs necessary after removing the fat in my liver/pancreas. As I said in a previous post, either this entry or the other prior one, “Is reverse, as in reversing T2D, a synonym for manage or a synonym for cure?”. Nobody has answered that so I set out to see if I could be my own test subject.

        • Vadym, and all. Sry I made that reference in a reply to you so I can see where you might have taken it as directed towards you. Sry. Is Juicing still a thing? It was, we tried it, the Fat, Sick, and almost Dead ‘thing’ even had a forum and the author had a ‘road show’. On the forum one woman openly said she had this condition, which she elaborated on, and went to see her doctor. Upon telling him of her new diet her doctor went off on her telling her that was the worst thing for her, given her condition. So she was querying the ‘group’ for advice. One such advise came in the form of something to the effect, “don’t listen to your doctor, he doesn’t know. Listen to your body, it’ll tell you what you need to do”. UH? Blind faith in a chosen “Messiah”, the guy who wrote “Fat, Sick, and Almost Dead”. The irony is I would guess he had no expectation or desire to be anyone’s Messiah. In Dr Fung’s prior blog, Diabetes, Prevention and Reversal, he never even mentioned the Dr created with discovering it was reversible. I think Dr Fung, in his webinars and books does an outstanding job of aggregating research and connecting dots of related datum. Dr Roy Taylor did original research proving diabetes was reversible that 80% of you pancreatic beta cells (insulin producers) are dead by the time you actually are diagnosed with T2D. That’s the ‘gold standard baby’. Dr Joseph Kraft, did original research and proved simply by utilizing glucose tolerance tests vs FBG and A1C you could reliably predict T2D upwards of a decade prior to it presenting in an annual FBG. Again, “gold standard baby”. I do think it a tad disingenuous to denigrate atkins or SB or Zone or CRaP diets as all failing the same way, “dreaded” plateaus then toward the end of his book indicate IF also can or does have plateaus. Not without some disambiguation. Is IF the Rosetta Stone for losing weight AND ending Diabetes (T2)? Maybe. I lost 125lbs through his so called CRaP dieting. Right now I am on a 18-20:6-4 IF and try hard to seriously reduce/eliminate sugars, refined flour products, and root starches. And I’ve gained some of that weight back. So will I have to limit my calories to 500/day for the rest of my life? Maybe, I hope not as that is really not the way I want to live. There is a new book out, “The Death of Expertise”. It kind of talks about what I eluded to, particularly in regards to advice like, “pay no attention to your doctor, your body knows what it needs”. Every so many weeks I see questions directed to the good Dr. I’ve yet to see any answers. Isn’t that a lot like prayer?

          I certainly didn’t mean to offend anyone. Apologies to those that were.

          • Sorry, 80% were NOT dead as is conventional dietitian wisdom.

          • Walt,

            I am glad we are back to discussing the subject itself; last thing I want is to discuss other people 🙂 To touch on Dr. Taylor, yes, this is the research that introduced me to the idea of IF originally. Our interactions with our local health practitioners is a very complicated topic with a lot of factors involved, and it’s a whole separate discussion, so again, I prefer to limit this exchange to the topic at hand.

            So, getting back to that. Let me try and summarize the comparison, and see if I get it right. You applied CRaP, and I applied IF. Your body is trying to regain weight, mine doesn’t. You face the possibility living on that measly 500 cal/day ration and don’t seem to be happy about that (justifiably so!); I eat with no calorie count and enjoy delicious foods every day. My major problem is a lack of mealtimes to try all the recipes in my folders – I’ll call it a good problem to have.

            Providing I summarized it correctly (and please let me know if I am in error), doesn’t it compare rather favorably for the theory advanced by Dr. Fung and others who side with insulin hypothesis?

  20. Dr. Fung… what about all of these studies?
    Are you saying they’re all bunk?

    • Stephan,

      As someone who actually likes to see a variety of evidence, I took a brief spin through most of the studies you linked to, but I didn’t find anything that seriously challenges Dr. Fung’s points. Specifically:

      – None of the studies directly (or even indirectly) compares the type of eating pattern that Dr. Fung recommends (e.g. something that maintains or raises calories out while moderating hunger and avoiding chronically elevated insulin) to some other diet

      – Most of the studies seem to be based on a group of people who maintained weight-loss longer term, however as Dr. Fung and many others (e.g. Peter Attia) have pointed out in various contexts, a naturally thin person or someone who had gained weight for a short period of time can maintain weight loss much more easily that someone who doesn’t have these advantages, so there is no reason to believe the study group has any relevance for people who don’t have these advantages. I didn’t see any data regarding how many of the people in the study group have these advantages or any other health or quality of life parameters, or how close they actually came to achieving overall health. So the study group seems far from “randomized” and may not be at all relevant to many people seeking to lose weight.

      – Given this, it looks like much of this is a correlation study such that one could conclude almost anything, and again, it does not compare methods or diets. I believe no study has ever shown high carb to be better long term for any group, although I am aware that for insulin sensitive people high carb may not be worse, at least for a while.

      – There was no data I could find about whether the people studied achieved close to a healthy weight; many people who report gravitating to LCHF did so after first losing similar amounts of weight on low calorie diets but stalling out with a lot of weight still to lose

      – This looks like the the same data set regurgitated by overlapping authors who are trying to draw a predetermined conclusion. Overall, very poor and non-actionable science.

      – There is sloppiness in the wording of the abstracts such as using out-of-context terms like “high fat” without saying whether the high fat was in the context of moderate-to-low carb or not

      – No mention is made of contradictory data such as what Dr. Fung and many others have cited in this and other posts
      In short this seems like the exact type of blame-the-patient-behavior that Dr. Fung is ranting against by saying “look, all these other people lost weight and you didn’t, so you should be doing whatever they’re doing”.

      So, while I’m open to be corrected, I’m going with, yes it/they are all bunk.

  21. Hyok Lee

    So much wrong in this article. Such an echo chamber.

  22. I still don’t understand something. I get that, if I eat more, my body will make more energy, burning off the increased calories. But how is that different from: if I eat less, my body burns my fat to make energy? I understand that if I avoid insulin spikes, there will be no hormonal impetus to store fat. I guess what I’m missing is: what impels my body to release my fat stores? If it’s simply that I intake an amount of food that’s insufficient to fuel my activities, why does my metabolism decrease instead of my ‘fat-utilization’ increasing? Don’t I want (in order to lose my fat stores) my fat-utilization to increase?

    I’m struggling to verbalize what is confusing me.

    • Obesity code pg 239 covers that Ann. It’s kind of an interesting process of 5 phases.

    • Here’s a clearer statement of what’s bothering me:

      Why, when calories are restricted, does the body conserve energy rather than simply withdraw the deficit from fat stores?

      • Your body doesn’t want to lose weight, so it will lower output before resorting to using fat stores. Your body is hoping food intake increases before things get bad enough that it needs to eat itself.

      • I believe that is insulin resistance. If you were following my discussion with Vadyam that is one of the primary sources of contradiction in OC. At one point he seems to indicate there is such a thing as starvation mode them changes course and says it’s a myth. In my attempts to disambiguate OC I can only assume it is insulin resistance. I’ve asked that question several times myself in these blogs and never got an answer.

        I do know whenever I try fasting for more than a couple of days my feet are freezing at night. I have never experienced the, I can only call it ‘runners high’ that is phase 5 of his ‘how the body responds to fasting’.

        • seebrina

          He does say in this instance some people are more resistant than others and that it could talk much longer fasting periods for a while to get things under control. I was doing 24 hour fasts which didnt get the results I was looking for in lowering my numbers. He puts those people on days and or weeks long fasts to combat that. I am severely resistant and all it took was back to back 3- 4 day fasts to see my morning bs to come down under 100. Some people need even longer fasts in the beginning. Now doing shorter fasts and my numbers stayed down so far.

      • Stephen T

        Ann, your cells won’t release fat to use as fuel until your insulin level drops. Your carbs are always used first. Hence the logic of reducing insulin by eating lower carb and fasting. If insulin is still high enough, you can’t access the fat stores even though you might be in deficit. I think this is when you’ll be getting a hunger signal even though there’s fat stores that could be used. Obese and overweight people who eat too many carbs are rarely in fat burning mode and insulin is removing the glucose and storing it as more fat.

  23. Ron Hunter

    Please Dr. Fung – gives us some follow up on this:

    As I looked at some LCHF studies, it appears that people do actually end up consuming fewer calories than before they started eating this way. As I recall in a number of the head to head calorie consumption was very close between the LCHF and the low fat, low calorie group.

    Is lower calorie consumption the result of lower insulin and leptin resistance?

    • seebrina

      It would make sense that they are eating less calories while in fat burning mode. If you are feeding your body 2500 calories a day by mouth , why then would it take calories from your fat stores? If you are burning a certain number of calories of your own fat than you would naturally be eating much less.

  24. Charles Grashow
    Persons successful at long-term weight loss and maintenance continue to consume a low-energy, low-fat diet.

    Subjects were 355 women and 83 men, aged 18 years or older, primarily white, who had maintained a weight loss of at least 13.6 kg for at least 1 year, and were the initial enrollees in the ongoing National Weight Control Registry. On average, the participants had lost 30 kg and maintained the weight loss for 5.1 years.

    Successful maintainers of weight loss reported continued consumption of a low-energy and low-fat diet. Women in the registry reported eating an average of 1,306 kcal/day (24.3% of energy from fat); men reported consuming 1,685 kcal (23.5% of energy from fat). Subjects in the registry reported consuming less energy and a lower percentage of energy from fat than NHANES III subjects did. Subjects who lost weight on their own did not differ from those who lost weight with assistance in regards to energy intake, percent of energy from fat, or intake of selected nutrients (iron; calcium; and vitamins C, A, and E). In addition, subjects who lost weight on their own and those who lost weight with assistance met the RDAs for calcium and vitamins C, A, and E for persons aged 25 years or older.

    • How do we know this isn’t the hungry and miserable diet that they are following? If the are eating so little for so long it certainly sounds like their metabolism is down-regulated. I don’t think there’s any question that one can keep weight off long term with a low calorie diet and this is especially true for naturally lean people who just ate too much for a while, however the point is what works for most people with the highest corresponding quality of life

      • Charles Grashow

        Why should we assume that these people are following a “hungry and miserable diet”?

        As for down-regulated metabolism perhaps that explains why Jimmy Moore – Dr Fung’s co-author – cannot get his weight below 300 lbs!

        • The Pooch

          Whatever is going on with Jimmy Moore, seems like it may not be working for him. And that proves or disproves what, exactly, for everybody else?

          Could we imagine (gasp) that different approaches will work for different people?

    • Hi Charles,
      This study has a major shortcoming. Only those who had been successful at weight loss have been included. It has completed ignored all of the data on those who were not able to maintain their weight loss. This is classic selection bias, and a study of this type can only be used to create a hypothesis. It doesn’t prove anything.

      It would be like doing a survey of rich people, and concluding that owning a larger house is the secret to becoming wealthy.

    • The Pooch

      Self-selected sample = selection bias. Not randomized.

  25. Vadym, it appears the software ended our prior thread as we’d be down to single letter column otherwise.

    You mentioned maintenance mode. Would you elaborate? I’ve only seen that term in the context of Atkins. I did answer, what I believe is, your last question but it may have be placed above where you asked it. Also, you mentioned Dr Taylor as what led you to IF. I’d like to think or, put differently, of all the research I did in following Dr Taylor’s clinical trials I’ve never seen him discuss anything other than a highly controlled 8 week extreme diet in order to eliminate intra-organ fat, specifically liver and pancreas. However, his current focus, to end in 2018 is on seeing if his work to that point, (the 8wk optifast protocol) can be transitioned to a primary care setting. Which I’d like to think is what I did albeit not via an 8 wk 700cal diet. So, another interesting point is to replicate that diet in the states would, I believe, mean using Slim Fast, which I believe Dr Fung would cringe at as it has lots of carbs,
    INGREDIENTS: Fat Free Milk, Sugar, Cocoa (Processed With Alkali), Canola Oil, Fructose, Calcium Caseinate, Gum Arabic, Cellulose Gel, Hydrogenated Soybean Oil, Mono and Diglycerides, Potassium Phosphate, Soybean Lecithin, Cellulose Gum, Carrageenan, Isolated Soy Protein, Artificial Flavor, Maltodextrin, Sucralose and ..

    • Walt,

      my maintenance mode is a soft regimen where I habitually stay on a low carb side but nowhere even close to ketogenic levels. I don’t fast on a regular basis anymore but throw in a fasting day or two if my weight upticks after some social event or, say, a vacation where I don’t watch any food intake whatsoever. The only thing that haven’t made it back into my diet is a junk food; other than that, for all practical intents and purposes, it’s normal effortless living.

      My fasting regimen wasn’t imitating Dr. Taylor’s model; his research merely informed me of possibility if diabetes reversal and gave a push toward intermittent fasting. I applied much easier 5:2 protocol, and later introduced some of the variations discussed by Dr. Fung. That wasn’t by preference, but simply by the order in which I discovered these fine gentlemen. The Obesity Code put much more solid understanding under what I was doing.

      Oh, and there is no way I would drink that Slim Fast thingy 🙂 Why on earth would I want all those nasties in my menu when there are so many delicious things in the realm of real food!

    • Also, your comparison is inaccurate. Fung clearly states the human body strives for homeostasis, that being liking the way things are specifically, in this case, body weight. If one accepts diet, small d, as what one eats, then I suspect if you walked away from your IF, you’d gain wait too. This goes to my question above, would you elaborate on ‘maintenance mode’? Fung doesn’t discuss maintenance mode at all with respect to IF. Presumably, once one achieves the desired weight loss the maintenance mode is doing whatever is necessary to maintain that weight until your body adjusts to it, making it the new set point. In the NIH sponsored post season 14 (as I recall) of Biggest Loser as much as 6 yrs later all of the contestants, save one, regained their weight back. As I have referred to elsewhere, another original research from someone else that Dr Fung referred to was the various responses the body has to fasting. the last one, after 5 days, is the synthesis of adrenilin and HGH to raise metabolism and protect against protein depletion. What can one infer from that? It takes 5 days of fasting for your body to raise your metabolism. And from that? Even fasting lowers your metabolism. So, yet another of the questions I’ve asked that have never been answered, if ‘protein conservation’ phase occurs after 5 days of fasting, how does it ever get to day 5 of fasting if you eat every single day if only for a single meal? So is the answer, magic happens? This is the dove tail to what you objected to. I am an engineer, I want facts, not religion.

  26. Hah? I did walk away from fasting after reaching my ideal weight, and I stay there. Homeostasis you mention has a set point; it clearly has been reset to the lower number during weight loss drive, by lowering insulin resistance/insulin levels, which IS the mechanism of setting that point.

    I am not sure where the miscommunication comes from. I am answering your questions, yet you continue asking them and saying that haven’t been answered… I must not be communicating clearly?

  27. I think we’ve reached the logical end of this conversation but, for some reason, you seem to think I am asking the same question you already answered. No, my time, actually, is too important. However, this is your quote, “To touch on Dr. Taylor, yes, this is the research that introduced me to the idea of IF originally. “. So, yeah, its reasonable for me to infer from that there is something published by Dr Taylor I didn’t see. Not beyond possibility but, as I’ve said, I took to “sciencing the shit out of it”, if you saw The Martian w/Matt Damen, you likely recall the reference. So, no, I am not trying to re-ask a question answered. I am merely drilling down. For instance you said low carb (but not ketogenic). Yet another question I asked on here nobody answered. My understanding is ketogenic is VLC, under 3% of calories. As I’ve said elsewhere, I thought I was doing good to be under 30% of total calories. The SAD, or rather the default MyFitnessPal has carbs at 55% of daily calories so I thought 30 was doing really well. There is a guy who frequents these blogs that I can safely say I’ve learned more from than I have by reading both Fung books. In fact, in a previous blog, months ago, I referred to him as Zen Master of low carb or some such. He was talking about frequently, at least at that time, being on a ‘modified’ 5-2 fast. Once he elaborated I suggested he wasn’t on a modified 5-2, he was on a 2-5 fast. As I recall, he laughed and accepted that was more accurate. He didn’t want to go more than 5 because that, he said, would reasonably require a doctor’s supervision. Suffice it to say, he is an individual I look forward to reading his thoughts on this.

    Again, per Dr Fung, per P. Felig, in an edition of Endocrynology, Vol 3 1979, pp. 1927 -1940 an Article “In Starvation” it takes 5 days to enter protein conservation, where HGH and adrenilin are produced to raise metabolism. Anyway, I believe we’ve exhausted this conversation. Parting thought, good on ya mate!

  28. Gary Van Exan

    Lots of interesting comments, I really enjoy this site. My view is that this is a personal journey for me. I’ve added elements in as I discover them, for instance, ketogenetic components about a year ago, I modified it to ultra low carb, because the general guidelines did not work for me,( in order to keep the blood glucose in the ‘normal’ range, I must stay below about 10 grams per day of unprocessed carbs, and zero processed carbs), close scrutiny and detailed data entry of health markers; ie: BP, blood glucose, blood ketones, diet diary, exercise diary, quarterly blood testing, the bonus of my doctor being completely onside….and a few more things that have evolved over the last 5 or 6 years. I don’t view this as a diet, but as a lifestyle change, because I see the preceding 60 years or so as the lifestyle that caused the problems. The last increment was intermittent fasting, which really speeded things up. On day 4 of a fast, I often achieve 4.2, or more, milli moles per litre, of blood ketones. I struggle with the notion of changing up my schedule in order to ‘not create’ a set point for my body. Still, in the last 15 months or so, I’ve seen all of my health markers ‘normalized’. Blood glucose has resolved from 7 to 8 mm/l to 3.5 to 4.7. I’ve lost about 60 pounds, all of my blood lipids surprise my doctor and I feel great. (which may be the most important marker anyway) I do about a half hour a day of high intensity interval training and follow it with about a half hour of infra red sauna, and I work about 13 hours a day.
    I enjoy the scientific observations and discussion, but for me, this is a personal journey. The biggest drawback in my opinion is the negative feedback from people who I discuss this stuff with. Without hands on experience, it’s difficult for many to understand what we, who are in the ‘trenches’ are experiencing and the difficulty and level of commitment that’s required.
    Keep up the good work and please continue to share.


  29. Gary Van Exan

    I probably should have added that reducing my caloric intake was something that occurred ‘naturally’. I did not consciously do that, but once I started my food diary, it became obvious that my caloric intake was well below the ‘average 2000 calories’ mentioned by Dr. Fung. I run between 1200 and 1500, except for zero on my fasting days, which are 2 or 3 per week. Once in increased my fat and oil intake, my total intake decreased, by and large normally. My carb intake runs about 6 to 10 grams per day. I have no desire to eat any more than I am eating, and did not even become aware of the reduction until I started the diary. I am not fanatical about the dietary restrictions except that I observe zero processed carbs ( the only carbs are green leafy vegetables), and this seems to be the characteristic that started the change. I worry that this low carb intake will reduce my metabolic rate, but I am still losing weight. I’m aiming for another 10 pounds or so. The next step in the journey is to maintain the gains for one more year…….I welcome the challenge.

  30. Thank you, I needed to hear this again this week! So tempted to fall back into calorie counting, the weight loss never last and I am miserable the whole time. No no no, it doesn’t work!

  31. I now refer to Dr. Fung’s theory instead as:

    Calorie Restriction As Secondary Stupid (CRASS)

  32. David Nyman

    I’m completely confused. Are we saying that if I reduce my calorie intake and I lose weight AND sustain that loss (which I did and have for many, many years) that I didn’t lose weight because of the reduction in calories? And I’m not maintaining it because of consistent calorific balance? And if I increased calorie intake I would simply expend more energy to compensate? I can’t seem to consort any of this with my experience. Which I say as a confirmed IF-er of 20 years duration.

    • seebrina

      I wouldnt think so since when you ate less your body then compensated by burning fat stores so your body was using about the same ‘calories’ to run itself , they just came from different places. After all your stored body fat is calorific. And this all hinges on insulin being kept low enough to access those fat stores.

  33. SimpsonsFan

    The 1:1 ratio is too simplistic. I’ve gone days without eating and not lost a pound. Just recently, I ate maybe 500 calories in one day, and gained over 1/2 a pound and 0.3% body fat…at least, according to my scale. I went off my diet at one point, didn’t exercise, ate a larger-than-normal meal, didn’t exercise the next day either, ate fast food (!!) (something I rarely do), and the next time I weighed myself, I’d lost 2lbs and almost 1% body fat!! So, clearly, I can gain weight during caloric deficit, and lose weight during caloric excess. It is more complicated than the simplistic “calories in/calories out” mantra.

    Most of my life I was very thin…naturally. While I usually ate once a day, I didn’t watch what I ate and didn’t exercise. (Hey…this was the free-wheelin’ ’80s & ’90s!) My weight stayed the same, whether I ate cheesecake or chickpeas. I didn’t weigh over 100lbs until some time in my 30s, and even then my weight was extremely stable at around 110lbs for several more years. Only the onset of perimenopause seems, in retrospect, to be the biggest player in my recent weight gain. And for the life of me, now I can’t maintain even a pound of weight loss, despite going days without eating, at times.

    It’s baffling, and no one seems to have a clear understanding why…or how… I literally ate celery sticks, a miso soup, 2 Brazil nuts, 2 seaweed snacks, and a green tea, yesterday, plus 1 hr in the gym, and gained a pound. So…take that, “calories in/calories out” monkeys.

    • You don’t gain weight right away, just because you ate light yesterday doesn’t mean you’ll be lighter today. Lots of factors are in play.. like the time of day you weight yourself, water weight, etc.

  34. seebrina

    Simpsons- Me too! The menopause hit and weight gain with it. Very difficult to lose too. Ugh.

  35. seebrina

    Simpsonsfan- Also its not recommended to judge your weight everyday since so many factors go into it. Exercise can cause muscles to hold water or the colon is holding waste even when you eliminate everyday. The bodies water stores can flucuate massively day to day. So lots a variables as to why weight changes daily.

  36. Effect of Alternate-Day Fasting on Weight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults

    They claim no difference of weight loss between diets after year of survey

  37. Since being Keto and regularly fasting, my hunger level is almost non-existent. Currently am doing a 42 hr alternate day fast but on feast days, I’m not real hungry and don’t get the 1200 kcals on my food tracker. Have been steadily losing pounds (about 2 per week) so am really loving this plan. Figure I’ll mix it up if the weight loss stops. My question is, is my calorie intake too low? Current weight is 137, starting was 165, 5’3″ and small boned, calories are about 650-800 on feast days. Macros are very good. Started the alternate day plan about 2 1/2 weeks ago.

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