So Is Jason Fung right...or wrong...is insulin even a factor in losing weight...and other issues.

I think they work!

I think they work because you eat less when you do them.

I think if they're a sustainable thing for you and easier to stick to than something more broad then go forth.

It has jack all to do with anything more magical than 'you eat fewer calories' though.

Fung *is* a quack. Do some research to discover why.

bubus05 wrote: »

First my own views. I think IF, fasting, keto work. At least in my own experience they do. From almost morbid obese at 285 lbs went to 190 lbs in twelve months, not super slim, but kind of healthy weight. I am a 50 year old relatively healthy male at 5.8.

thanks for asking!

I can't answer the insulin part, but I'm sure someone will chime in. Important is here: It worked for you. You lost about 2lbs per week, which is great success. Would the same work for someone else? For some it would, for others it wouldn't because not everyone thrives on keto, not everyone can fast and not everyone can do IF because that's their genetic make. However, eating less than what the body burns over a period of time works for everyone, and likewise everyone will gain weight if eating structurally above maintenance calories regardless of their macro and meal timing preferences.

He's not quite into Dr. Oz territory, but he comes closer pretty much everyday. Insulin isn't some devil thing...it's necessary and is a chemical hormone that directs energy to every cell in your body...to say it is the "fat hormone" or whatever is either zero understanding or purposefully misleading...I'd go with the latter. Insulin directs energy to every cell in your body...it is also the chemical hormone most responsible for building muscle.

Part of the problem is that he supposes that either everyone is sick and insulin resistant...or that even if you're not, you should be eating in this certain way. Why would an otherwise healthy person want to inhibit the body from doing what it's supposed to do? For a diabetic, the problem is that insulin response is actually inadequate to bring down blood glucose levels...so the choice is to either take insulin (if insulin was so "bad" why would people have to take it as a prescription) or take measures to keep blood glucose levels down...ie IF and Keto.

Basically, for an otherwise healthy person, his rhetoric is just that...and frankly, even for a diabetic, what he prescribes isn't necessary. My dad was a type II and controlled that with diet and didn't ever do IF or Keto.

Unless you have metabolic syndrome or insulin resistance the answer is no -- it doesn't matter.

My sample of one experience is: I've followed the CICO model on both high carb and lower carb diets. At my lowest adult weight I was eating ~300 grams of carbs per day, most of them simple carbs like bread and pasta. My weight has always matched the CICO model regardless of my carb intake. I'm in weight loss mode now and eating far fewer carbs and hardly any simple carbs and the weight loss still matches the same CICO model.

Oh check his net worth too. He's apparently worth a little over 1.2 million. I'd keep writing about pseudoscience too if I kept making that money. Regardless of what detractors say. It's like religion...............there's always going to be followers and those who'll pay.


A.C.E. Certified Personal and Group Fitness Trainer
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Been in fitness for 30 years and have studied kinesiology and nutrition

bubus05 wrote: »

AnnPT77 wrote: »

As a thought experiment:

If Fung is correct at some deep universal human physiological level, how does *anyone* ever lose weight and remain at a healthy weight long term, without doing *any* of IF, fasting, or keto?

Many people here (I'm one), and (for example) in the US National Weight Control Registry say that they've lost weight and kept it off long term without using IF, fasting or keto.

How is that possible? Do you believe we're mistaken about (or misrepresenting) what we do, or our results?

There are any number of articles critiquing Fung's theories in detail, at a research-findings level, from mainstream RDs, other academics, well-credentialed trainers, and more. They're not hard to find.

But the core question is above: How do you explain results from those who didn't follow Fung's "essential" methods?

I have no doubt that IF, fasting, keto can be effective. I don't even doubt the self-reports of those who find them near-magical tools. But the Fung-theory underpinnings simply don't pass the common sense sniff test, for me, because other methods work, too.

I dont believe you are mistaken or that you are misrepresenting what you do. I respect your opinion and everyone's opinion here. I kind of came to the conclusion that what works for some may or may not work for others, there is no absolute best when it comes to how to lose weight, except maybe the issue of calorie deficit, we all seem to agree on that. I can't even explain how I lost what I lost, I am happy nevertheless, much less how others lose with say a high carb diet. Whatever works works...
I agree with the above posts, this industry is a cash cow, and Fung is taking full advantage of it.

As long as there is a calorie deficit, anyone will lose weight on any combination of macros or eating protocols. If someone only has access to a set number of calories which equals a calorie deficit for them, they will lose weight.

Since most of us have access to many, many more calories than we need, the issue becomes ADHERENCE to that calorie deficit.

Keto and IF made it easier for you to adhere to a calorie deficit and that's great. We're happy for you.

However, you'll get pushback if you suggest it is the ONLY way, or that there is something special about it for the general public. There really isn't.

And while I am spamming this thread:

I don't doubt that every program out there will work for some people. I also don't think any single PROGRAM has any incentive to want to see people reach long term success (Ie: you need the program for it to be sustainable/know what's up OR you have to go back to the program when you fell off and buy more products/information), believe the weight loss industry is predatory and like heck will any of them get my money.

I can COUNT just fine by myself, and if I fall off going back is free and not putting money back into the pockets of an industry preying on people and incentivized to see people fail and/or stay ignorant.

If you eat over your maintenance calories, you'll gain weight, no matter what other diet tactics you deploy.

If you eat under your maintenance calories, you'll lose weight, no matter what other diet tactics you deploy.

If there were two people, A and B, both 250 pounds and trying to get to 200, and you had to bet which one would get there, and A's methodology is to eat a 500 calorie per day deficit, and B's is to do keto and IF without cutting calories, I highly recommend you put your money on A.

Some things like IF (which I have done more or less continuously for 18 months) help people lose weight, but it's important to distinguish between "things that help you stay in a calorie deficit, which causes you to lose weight" vs "things other than calorie restriction that directly cause weight loss." I do not believe the latter exist, except perhaps at the tiniest margins where it doesn't much matter.

Nor does anyone else believe it, deep down. Everyone knows you need to say no to the chocolate chip cookies if you want to get into those college jeans, and it has nothing to do with macros or Fung. I found parts of the Fung book interesting, but in the end, if you read Fung while munching on carrot sticks, you're good to go, and if you read Fung while eating a 24 oz rib eye, you're not.

wunderkindking wrote: »

I think they work!

I think they work because you eat less when you do them.

I think if they're a sustainable thing for you and easier to stick to than something more broad then go forth.

This. 100%.

To elaborate, and to be honest, given your own post, I'm not even sure what the question still in your mind is.

bubus05 wrote: »

First my own views. I think IF, fasting, keto work. At least in my own experience they do. From almost morbid obese at 285 lbs went to 190 lbs in twelve months, not super slim, but kind of healthy weight. I am a 50 year old relatively healthy male at 5.8. I have done all three but I have to admit lately I do have cheat days with high carbs, surprisingly even for me high carbs have not really effected my weight loss, if anything I felt I had more energy to put more pressure on my trainings. The only thing I have been very consistent is being in calorie deficit.

This is not surprising. It's the calorie deficit, of course, that causes weight loss. So if you had/have a calorie deficit, you will lose, You yourself say that high carb days haven't affected your weight loss. Similarly, for many of us who didn't fast or do keto or IF but lost weight, it's because we ALSO had a calorie deficit.

Why do some people struggle to lose and then do keto or IF and lose? Because many people are BAD at figuring out how to get in a calorie deficit, especially if they don't have a good understanding of food (and the cals they have or what they find sating) or problematic eating behaviors or are prone to mindless eating. Many who eat high cal foods also think they don't eat much (low volume) but are shocked by the cals, and some will diet by being very restrictive and then having cheat days and not realize they could be eating so much in the cheat day to prevent the deficit.

For some of these people, something like IF (which has clear strict limits and can take off the table food in times and situations where overeating was common) or keto (which makes mindless eating harder and may take off the table foods that one tended to overeat, although eventually most can probably find substitutes) can be an easy way to create a calorie deficit, at least initially, and particularly if one is not yet good at logging or finds doing so unappealing. Also, some people struggle when dieting since they don't know what is sating to them, and many find that keto decreases appetite (many, not all).

None of this supports Fung, at least not his why. Did he find a way to give people magic mumbo jumbo to get them to try things that work for more mundane reasons? Yeah. But not because insulin blah blah, magical fasting. So I see him as a charlatan.

What I found is that essentially both sides argue the same thing except that, Fung says you go low insulin than you start burning fat and than you will lose weight. The other side says no he is wrong, you go into calorie deficit than your insulin level go down and than you start burning fat and than you will lose weight.

No, it has nothing to do with insulin. There have been studies (Kevin Hall's, for example) comparing people in the same calorie deficit, but one group has very low insulin and one does not. The one that did not actually lost a bit more fat, although I would say they were close enough to be basically the same.

Calories are the energy that one needs to function at one's given level of activity and exercise. If you don't have enough energy to fuel everything, it needs to come from somewhere, and so the body burns fat. Period. This happens whether one IFs or ketos or whatever.

To the extent Fung claims cals don't matter, insulin somehow magically prevents weight loss and low insulin causes it, he is wrong, and like I said, being somewhat shady, I suspect. Does Fung know calories in/calories out doesn't sell books and is hard for some to accept/adhere to and also realize in his head that what he is recommending will cause a calorie deficit in many people? Well, I kind of think so, but can't know for sure.

Fung's claims are debunked not only by the many other experts who have addressed them, but by the fact that there are likely way more people on this website and the National Weight Loss Registry and, well, the world who have lost weight without doing IF or keto than those who have.

(And it's also quite possible to gain doing IF or keto, and more likely when it's not a new thing that has caused one to be extra mindful about food and eating behaviors -- something that happens with any number of new diets or new ways of eating.)

33gail33 wrote: »

bubus05 wrote: »

I am honestly curious what our own experts on MyFitnesspal think about the guy who is kind of famous or infamous-depending on whether you believe him or not- with his views on IF, fasting and keto. He is in favour of all of these three strategies though his favourite subject seems to be fasting, so is he wrong?
On a number of posts and replies I have seen these kinds of statements 'Fung was debunked by experts with more knowledge' or 'as soon as I've seen him mention I bailed'. Whenever I mention any of these three strategies and say why I think they work I get debunked that is for sure. I was suggested to ask the community what they really think so here it is.
First my own views. I think IF, fasting, keto work. At least in my own experience they do. From almost morbid obese at 285 lbs went to 190 lbs in twelve months, not super slim, but kind of healthy weight. I am a 50 year old relatively healthy male at 5.8. I have done all three but I have to admit lately I do have cheat days with high carbs, surprisingly even for me high carbs have not really effected my weight loss, if anything I felt I had more energy to put more pressure on my trainings. The only thing I have been very consistent is being in calorie deficit. I admit Fung got me into doing keto combined with fasting, so I am kind of grateful to him. His views on how insulin levels effect weight loss seemed credible so I tried to follow his advice and I feel I am successful, never felt better. Honestly, after years of unsuccessful attempts at losing weight here is a guy who explains how to do it and it works, a damn miracle in my book. And than I read on these pages I am wrong and Fung is wrong. That he is debunked by experts. WTF??? So I went to see the other argument. What I found is that essentially both sides argue the same thing except that, Fung says you go low insulin than you start burning fat and than you will lose weight. The other side says no he is wrong, you go into calorie deficit than your insulin level go down and than you start burning fat and than you will lose weight. The question of what came first the egg or the chicken...Both sides seem to be right, with one side claiming the insulin level is not that important it is the calorie deficit that is important. True, Fung doesn't speak of the importance of calorie deficit though, what he is saying is that with weight loss one's metabolism will necessarily go down so you can't really rely on that. That makes sense too, but the argument about CICO also makes sense. So I am at a loss why I lost the weight TBH. Fung seems to be right- i mean his strategy worked for me- but he seems to be wrong too, which is it...
I am curious to hear you guys sharing your views on the subject.

I get your confusion - MFP will never agree with anything that isn't straight CICO - and anything else that works towards weight loss ONLY works because it puts you in a calorie deficit. I think there is a little more nuance with regards to the influence of hormones, metabolism, gut health etc than that - but I don't know that it is enough to make a huge difference in the "real world" - because yes any calorie deficit diet will result in weight loss.
I am not familiar with Dr Fung but my own personal doctor does believe that gut health and hormones are an important factor for metabolism and weight loss (she is a gp but has specialized practice in chronic illness and funcitonal nutrition). So while I do trust her opinion, it is hard to not have doubts creep in when you hang around here and it is constantly drilled into your head that those things don't matter. It's a conundrum for sure. But what I am doing is working for me (for my health and weight loss) so I'll just stick with it.

Of course those things (bolded) are important, when it comes to effective weight loss and maintenance, and I say that as a major, quite absolutist, CICO believer. (Noting that CICO is the energy balance equation; calorie counting is the method, and IMO calorie counting will work better for some people than others, for complex reasons, just like any other method.)

Even if we talk about calorie counting (done consistently and accurately), things like hormones, gut metabolism, etc., affect the weight loss process via appetite, cravings, energy level, body composition, etc., that may either (1) reduce CO when CI is or had previously been reduced, (2) cause an individual to have a lower (or higher) effective calorie burn (perhaps even via things accurately called "metabolism") than so-called calculators predict, or (3) make a deficit calorie goal psychologically, perhaps even physically, nearly impossible subjectively to stick with.

That's without even unpacking that "accurately" term in the first sentence of the preceding paragraph. All this stuff involved in calorie counting is estimates. It's hard to think of anything top-level relevant that's an accurate *measurement* vs. estimate, for most people. (Scale weight could be close, with specialized professional scales . . . but they don't measure fat loss, just the body/gravity/earth relationship at one moment.)

Just saying "weight loss comes down to calorie deficit" (true IMO in a direct, literal sense) doesn't imply that someone can just blindly apply codified rules and everything will be fine, physically, psychologically, socially, and more. That would be silly.

I disagree that "MFP will never agree with anything that isn't straight CICO". (Even if you meant "calorie counting" rather than "the calorie balance equation".) First, "MFP" is not a unitary entity, it's a bunch of very diverse people.

There are posts here every day suggesting strategies to deal with the factors you're talking about. There are are posts here every day acknowledging that methods other than calorie counting can work (yes, by creating a deficit). There are posts here nearly every day telling certain people that maybe calorie counting is a bad idea for them (some in anorexia recovery, for example). There are posts about the science behind adaptive thermogenesis, the effect of diet breaks on hormone levels, the importance of a well rounded way of eating for gut microbiome and general health, and more . . . from CICO and calorie counting believers.

When it comes to practical weight loss, there are individual factors that matter (gut microbiome and genetics may have an influence on some of them), and there are universal systemic factors that can matter because human physiology is complicated, with lots of mutually-cross-influencing aspects. Trying to make it absolutist or black and white (log fewer calories than some calculator says, lose weight) will work for some, but there's more to it than that, sure, as a practical thing in a real human's life.

Do some CICO/calorie counting believers have an overly simplistic view, that "log fewer calories than some calculator says, lose weight" is all that there is to it? Of course. Simplistic thinking has representatives in every theoretical camp.

33gail33 wrote: »

bubus05 wrote: »

I am honestly curious what our own experts on MyFitnesspal think about the guy who is kind of famous or infamous-depending on whether you believe him or not- with his views on IF, fasting and keto. He is in favour of all of these three strategies though his favourite subject seems to be fasting, so is he wrong?
On a number of posts and replies I have seen these kinds of statements 'Fung was debunked by experts with more knowledge' or 'as soon as I've seen him mention I bailed'. Whenever I mention any of these three strategies and say why I think they work I get debunked that is for sure. I was suggested to ask the community what they really think so here it is.
First my own views. I think IF, fasting, keto work. At least in my own experience they do. From almost morbid obese at 285 lbs went to 190 lbs in twelve months, not super slim, but kind of healthy weight. I am a 50 year old relatively healthy male at 5.8. I have done all three but I have to admit lately I do have cheat days with high carbs, surprisingly even for me high carbs have not really effected my weight loss, if anything I felt I had more energy to put more pressure on my trainings. The only thing I have been very consistent is being in calorie deficit. I admit Fung got me into doing keto combined with fasting, so I am kind of grateful to him. His views on how insulin levels effect weight loss seemed credible so I tried to follow his advice and I feel I am successful, never felt better. Honestly, after years of unsuccessful attempts at losing weight here is a guy who explains how to do it and it works, a damn miracle in my book. And than I read on these pages I am wrong and Fung is wrong. That he is debunked by experts. WTF??? So I went to see the other argument. What I found is that essentially both sides argue the same thing except that, Fung says you go low insulin than you start burning fat and than you will lose weight. The other side says no he is wrong, you go into calorie deficit than your insulin level go down and than you start burning fat and than you will lose weight. The question of what came first the egg or the chicken...Both sides seem to be right, with one side claiming the insulin level is not that important it is the calorie deficit that is important. True, Fung doesn't speak of the importance of calorie deficit though, what he is saying is that with weight loss one's metabolism will necessarily go down so you can't really rely on that. That makes sense too, but the argument about CICO also makes sense. So I am at a loss why I lost the weight TBH. Fung seems to be right- i mean his strategy worked for me- but he seems to be wrong too, which is it...
I am curious to hear you guys sharing your views on the subject.

I get your confusion - MFP will never agree with anything that isn't straight CICO - and anything else that works towards weight loss ONLY works because it puts you in a calorie deficit. I think there is a little more nuance with regards to the influence of hormones, metabolism, gut health etc than that - but I don't know that it is enough to make a huge difference in the "real world" - because yes any calorie deficit diet will result in weight loss.
I am not familiar with Dr Fung but my own personal doctor does believe that gut health and hormones are an important factor for metabolism and weight loss (she is a gp but has specialized practice in chronic illness and funcitonal nutrition). So while I do trust her opinion, it is hard to not have doubts creep in when you hang around here and it is constantly drilled into your head that those things don't matter. It's a conundrum for sure. But what I am doing is working for me (for my health and weight loss) so I'll just stick with it.

I could be wrong, but I don't think anyone on MFP is saying gut health, hormones, etc., don't matter. One person will have a TDEE of 2100, and another person who's the same gender, height, weight, etc., will have a TDEE of 2200 or 2150 or 2035. Individual physiologies clearly differ and one's TDEE reflects the sum total of all the things that are going on inside your body, inclusive of insulin levels, other hormones, etc. etc. etc.

But in the end, you gotta be in a calorie deficit to lose weight, and the size of that calorie deficit will determine how much weight you lose. Calorie deficit has always been the most important factor, by far, in weight loss and always will be, except in the case of quite unusual medical conditions. Whether there's 5 or 10 % at the margins that can be influenced by things other than calorie deficit, who knows, but those things are hardly the basis of a successful weight loss plan. Keto, IF, all may play a peripheral role in weight loss beyond their impact on helping one stay in a deficit, but the key word there is "peripheral".