So a few weeks ago, we published an infographic which showed that all weight loss diets work through caloric restriction and, consequently, through the resulting caloric deficit.
A few people objected to it, saying that body composition and health are not just about a caloric deficit but, rather, also about food quality.
Here’s the thing: WE AGREE 100%!
We’ve actually gone out of our way several times in a few articles to make this point crystal clear. We even mentioned it in the first article we ever published, where we talked about the “secret” to fat loss.
So no disagreement there. For optimal health and body composition, things like macronutrient amounts, fiber intake, food quality, meal timing and so on are important.
This is, of course, why the majority of the calories in our custom-made sample meal plans, that are part of the online fitness coaching services we provide, come from minimally-processed, micronutrient-dense foods.
The above shouldn’t, however, distract us from the fact that for a net increase or decrease in the body’s energy stores to take place, an imbalance between energy intake (from food) and energy output (from activity) must happen.
Practically speaking, for fat loss to occur, caloric restriction has to take place (or at least an increase in energy expenditure without a concomitant increase in caloric intake).
This is something that is objectively true and which the entire scientific community agrees on, by the way.
Strangely enough, however, an obesity doctor (well, a nephrologist, in reality) seems to disagree.
A ranty post by Dr. Fung
So a few days after the above infographic was published, Dr. Jason Fung responded with a ranty post on his blog (which you can read here) essentially claiming that caloric restriction doesn’t work for weight loss in the long term.
Now, if you go through his entire article, you’ll notice that his argument essentially boils down to that caloric restriction doesn’t work for weight loss in the long term, despite people adhering to their diets.
He even shares a couple of graphs from a few studies which show that, initially, weight loss occurs during calorically restricted diets, but then weight regain happens as weight slowly creeps back up during the months and years that follow.
Although Dr. Fung doesn’t offer an explanation as to why the weight is regained despite the subjects complying to their diets, he seems to suggest that this happens because of a decrease in energy expenditure.
Let’s not get ahead of ourselves, though. Let’s analyze Dr. Fung’s points one by one.
Changes in metabolic rate with caloric restriction
After the first paragraph, Dr. Fung goes on to talk about energy balance and the First Law of Thermodynamics, essentially agreeing that it always holds true.
He goes on to state that (and these are direct quotes, by the way):
- “If you eat less calories, you will burn less. So there is no overall change in body fatness”
and that
- “Basal metabolism may increase or decrease up to 40%.”
So are the above statements true?
Well, they are mostly inaccurate, although they have an ounce of truth to them. It’s true that caloric restriction results in a decrease in energy expenditure and that hypercaloric diets result in an increase in energy expenditure. However, the statement that the basal metabolism (i.e. BMR/RMR) may increase or decrease by up to 40% is not supported by any scientific research.
So how much does BMR/RMR increase/decrease with over- and underfeeding?
With regards to overfeeding, the largest BMR increase that we have found in studies lasting at least 2 weeks (and after adjusting for weight gain) is around 17% – i.e. nowhere near the 40% that Dr. Fung claims. Moreover, this scientific research paper suggests that the average BMR increase with overfeeding to be around 10%.
What happens to our metabolic rate with caloric restriction (underfeeding) then?
From what we could find, the largest drop in RMR in weight-stable conditions (and after adjusting for weight loss) was seen in the Minnesota Starvation Experiment, which recorded a (drumroll…) 15% drop in metabolic rate. Yep, still nowhere near the 40% which Dr. Fung claims. It’s also worth noting that this was a semi-starvation study, where subjects were in a severe caloric deficit until they reached around 4% body fat.
So where did Dr. Fung go wrong in his calculations?
Well, Dr. Fung probably failed to consider that reductions in metabolic rate should account for weight loss or gain, since a smaller body will burn fewer calories and a larger body will burn more. So, when weight loss occurs, the honest thing to do is to compare the new BMR to the predicted new BMR (based on the reduced body weight) and not to the old one (i.e. before weight loss had occurred).
On a relevant note, as you can see in the table below, science has a pretty good idea about how much different components of the human body contribute towards the metabolic rate.
Dr. Fung’s CRaP
In the next paragraph, Dr. Fung refers to the approach of caloric restriction for weight loss as CRaP (Caloric Reduction as Primary).
If you delve a little more into it by reading more articles on his blog, you’ll notice that he is, essentially, making a number of assumptions on what he thinks researchers and fitness professionals think, and then basing his arguments on that.
More specifically, Dr. Fung thinks that we think that:
- a change in one side of the energy balance doesn’t cause a change in the other
- food intake is not affected by hunger, hedonic, sociocultural and other variables
- exercise (or TEA) is a major component of total energy expenditure
- the endocrine system is not involved in the regulation of adipose tissue
In reality, however, no respected nutritionist, dietitian, or fitness professional thinks that the above issues relating to the CICO (calories in, calories out) model hold true.
Weight loss and long-term maintenance
Dr. Fung continues by asking the following question:
“So, where is the evidence that reducing calorie intake as the primary strategy results in long term meaningful weight loss?”
Okay, so let’s see what scientific evidence we have:
This 10-year observational study of 2886 men and women found that, after 10 years, average weight loss with caloric restriction and an increase in activity was around 50 pounds.
The researchers reported that “decreases in leisure-time physical activity, dietary restraint, and frequency of self-weighing and increases in the percentage of energy intake from fat and disinhibition were associated with greater weight regain.”
Essentially, weight loss success in the long term was found to be associated with staying active, controlling caloric intake, keeping track of body weight and not eating huge amounts of fat.
The authors also reported that “long-term weight-loss maintenance is possible and requires sustained behavior change”.
Truly ground-breaking stuff!
Why do people regain lost weight?
Dr. Fung continues by presenting a couple of studies (along with a few graphs), which show that a large proportion of the weight lost by most subjects is regained in the years that follow.
Here’s the thing: we’re not saying that people always succeed in losing weight and keeping it off. Quite to the contrary. Most people seem to regain much of the lost weight after a few months and years.
Here’s where Dr. Fung is being brutally dishonest, however (or, at the very least, embarrassingly misinformed): He claims that, in those studies, weight regain happened despite subjects adhering to their diets.
Here are a couple of direct quotes from his article:
- “In a pattern familiar to every person who has ever dieted, the weight starts to regain despite continued compliance to the diet”
- “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 where we strongly disagree with Dr. Fung, since a large body of scientific evidence clearly shows that weight regain happens exactly because of lower dietary adherence and poor compliance over time.
First and foremost, here is some research which compared different diets (Atkins, Ornish, Weight Watchers and Zone) and which found that adherence to caloric restriction (even when it’s self-reported) plummets over time.
Here’s one of our favorite quotes: “in the long run, sustained adherence to a diet rather than diet type was the key predictor of weight loss and cardiac risk factor reduction in our study.”
Here’s a table from the same study, showing that all diet interventions resulted in meaningful weight loss at the start, but weight regain slowly started to take place as the months passed, evidently because of lower dietary adherence.
Finally, here’s a graph from the same study showing that there is a statistically significant correlation between weight loss and dietary adherence.
Moreover, here’s a recent meta-analysis which compared weight loss between low and high carbohydrate diets (and included 7286 individuals) and found no significant weight loss differences between the diets after 12 months.
The researchers concluded that: “significant weight loss was observed with any low-carbohydrate or low-fat diet. Weight loss differences between individual named diets were small. This supports the practice of recommending any diet that a patient will adhere to in order to lose weight.”
Here are a few more of our favorite quotes from the study:
“These findings support recent recommendations for weight loss in that most calorie-reducing diets result in clinically important weight loss as long as the diet is maintained”
and
“because different diets are variably tolerated by individuals, the ideal diet is the one that is best adhered to by individuals so that they can stay on the diet as long as possible.”
Notice a common pattern there? Yep, dietary adherence TRUMPS everything else.
We won’t bore you with any more studies by the way. The above is a meta-analysis and is literally loaded with references you can check out yourself.
Conclusions and recommendations
So here are our conclusions and recommendations. Sadly, they are neither ground-breaking nor book-selling, but that’s life.
The focus of ANY weight loss intervention should be to create a caloric deficit with a diet that is:
- composed primarily of minimally-processed, micronutrient dense foods
- has enough protein to prevent losses in lean body mass
- doesn’t create deficiencies in micronutrients
- honors the individual’s personal preferences with regards to meal timing, food choice, and so on
- can be adhered to in the long term
- promotes a healthy relationship with food
NOW BUY OUR BOOK, DAMMIT! Ok ok, we don’t have one… yet.
In the meantime, share this post!
What next?
If you enjoyed this article, you’ll probably also like these ones as well:
- Why You’ve Stopped Losing Weight (and What to Do About It)
- 10 Weight Loss Tips for Easier and More Successfull Dieting
- The Ketogenic Diet For Fat Loss: What Science Taught Us 40 Years Ago
Good one 🙂
To be honest, as a researcher from another (related) field, this ongoing debate is hard to follow. Both sides (you and Dr. Fung in this case, but I’ve seen this with others) seem to cherry pick and construct straw man arguments.
I’d rather not get into long debates, but here’s an example:
You say he’s wrong to point out that calorie restriction failed, even if subjects adhered to their diet in the studies he’s cited. But you then cite other studies to support your point. Did you check the studies he’s cited?
Cheers,
Carl
Hey Carl,
Thanks for your comment.
Absolutely! I checked the studies Dr. Fung cited and could not find anything suggesting that researchers assessed dietary adherence. If you want to check yourself and don’t have access to the full-text articles, I’d be happy to send them!
Man this doc Fung is retarded. His comparison to kcal in & kcal out is like the earth isn’t round but its square.
Wtf?? Not scientific proven just horseshit lmao
Intermittent fasting works best for people with insulin resistance. Yes obviously for someone who does not have insulin resistance who is overweight by eating too many calories can cut calories and access their stored fat easily making up for the missing energy from stored fat. This is why someone like Kim Kardashian can eat a 1700-1800 calorie diet and workout and consistently lose weight and keep it off. She is accessing her stored fat every day. For someone with insulin resistance, their bodies cannot access their stored fat, so the only way to maintain weight loss, they constantly have to lower their calorie intake to match their new metabolic rate in order to keep losing and maintain. This is a losing battle as eventually they would be eating nothing and starving.For example, if Kim had insulin resistance, she would probably have to lower her calorie intake to 1200 calories or less to get to 120 pounds and maintain at 1200 or less when she should have been able to achieve weight loss eating 1800 calories and maintaining around 1700. Fasting helps someone with insulin resistance to deplete their insulin so they can access their fat stores. Basically it is how they can cure insulin resistance and make their bodies like Kim Kardashian’s body. Yes they would have to eat a low carb diet to help lower insulin and create a calorie deficit by food or working out or both to acheive weight loss. The benefit is they would not have to eat less and less forever to maintain weight loss. Fasting will also work for people without insulin resistance. My guess is those are the people who lose 20 pounds in 1 month like some people boast 🙂
Thanks for your comment, Leslie!
I am not sure where exactly you are getting this information from… Mind sharing it with us?
I 100% agree with you, Leslie. And…I get the information from PERSONAL EXPERIENCE!
No studies needed, no personal coaching hours, ebooks or newsletters needed.
I have insulin resistance and no problem accessing my fat stores. I practice feast and famine with intermittent fasting and some longer fasts. I am losing weight easily without eating a low calorie diet on a daily basis. This way of eating results in fewer calories over time, but doesn’t slow my metabolism down as with past diets where I seem to gain the weight back immediately upon adding more calories. Now I can eat my BMR recommendation plus extra calories for a week without any regain. Fasting also seems to help reset my body’s new weight set point after loss.
I agree with all you have written. Perhaps Dr Fung meant as a person ages, he cant maintain weightloss if your hormones change, health issues change,etc,,? Certainly even if we do all the right things, if a dr put us on a medication that causes weight gain, that would also affect us.
Thanks for your message, Betty!
Well, contrary to what most people think, age-related hormonal changes are more likely to affect where we store body fat than if and how much fat we store. It’s also worth noting that basal metabolic rate doesn’t drop much as we age. People usually gain weight mainly because they start becoming less active both in terms of exercise and in general day to day living (Non Exercise Activity Thermogenesis).
Some of our postmenstrual clients have actually lost over 30 pounds and maintained it for 5+ years!
With regards to medication, it can get pretty complicated, since some medication can cause massive increases in water weight, while some can cause feelings of tiredness and hunger. Depending on the situation, the gain in weight could be actual body fat or merely just water.
Interesting recent addition.
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature24022.html
Nice one! Thanks for sharing!
Just something important to bear in mind: this study was on mice, so it would be a good idea to take it with a grain of salt.
GARY TAUBES
Author of The Case Against Sugar, Why We Get Fat and Good Calories, Bad Calories.
If you have read these, where does this author fit into this discussion? Thanks
Hey Steve, thanks for your comment.
Gary Taubes is great at writing science fiction!
On a serious note, Gary is a proponent of the CIM of obesity, which has been pretty much debunked in scientific research. Gary debated Alan Aragon at the Epic Fitness Summit in the UK a couple of years ago on this. This should make it clear how it went: https://www.youtube.com/watch?v=gSEVkiTCCNw
Also, here’s a description of how the debate went by Ben Carpenter: https://www.youtube.com/watch?v=aRCv5RWXWx8
I think both of you make valid points. However, it is not black and white: you lose weight or you don’t. I started putting on weight in my teens and have been “dieting” for over 50 years. In the beginning I dropped the weight effortlessly by dropping starches (potatos) and sugar out of my diet. After menopause I started to put the weight back on and no amount of cutting back on anything has shifted it. 17 years ago I was diagnosed as type 2 diabetic. Once again I started changing my diet in an effort to lose the weight and increase my insuline sensitivity, no avail. My body has a life of its own, and does the exact opposite of what is expected. What happens in most diets you drop things out without replacing them with other sources, creating deficits, whether they be calories, vitamins, nutrients. How does the body (i.e. your gut biome) react in a deficient state? It tries to compensate and get the deficiences back but from where? Apparently not from your fat stores. So how do I solve the problem in later life having jiggled with my metabolism for over 50 years? Not another diet apparently.
You just haven’t found a good coach to help you with your weight loss goals yet!
On a serious note, we’re aware of all the hormonal issues that accompany aging and menopause. Many times, the best solution is to see an endocrinologist to help you sort out your hormones before trying to lose weight.
I’m actually researching claims that Dr. Fung is a quack, as while I’m a fasting enthusiast, I’d rather have good, well-researched doctors instead of people trying to sell fasting products and programs.
One point I want to make is, is it easier to sustain a fasting lifestyle or a calorie controlled lifestyle? In my experience, despite the fatigue associated with fasting, the discipline required is much less (in a period of my life, I had 5 days of 1200 calorie days with 2 cheat days, frequent cycling exercise, and at the same time I did 72-hour fasting every month). Especially with short-term fasting, stimulants can help you cope with the hunger and the fatigue.
The basic essence of the debate seems to be: of course CICO applies when it comes to body weight. But do we consume fewer calories over many small meals, or do we have 1-2 big meals with time devoted to exercise and fasting to achieve a reasonable “average daily caloric balance”?
And for the record, my preference is for an ascetic calorie controlled lifestyle with fasting kicking in once weight/body fat exceeds a threshold, i.e, you try not to overeat, but once you do, you have a failsafe to throw you back under the target weight.
Hi Inst and thank you for your comments,
In general, and taking into consideration all the research I’ve read on IF as well as my experience with hundreds of clients, I think that some IF variations (mostly the Time Restricted Feeding ones, which have you fasting for a few hours per day), can be a little easier to adhere to than frequent meals throughout the day. I feel that, for most people, something as simple as 16:8 IF (so just skipping breakfast) is great for naturally helping them eat less.
you are essentially advocating the biggest loser diet of reduce calories and increase movement… while yes this works on the show and elsewhere do you ever wonder why there is no “biggest loser reunion?”
its because they are all fat again! there in lies the mystery.
Thanks for your comment, Rumi.
I recommend that you re-read the article, as it seems you have missed a few key points:
– ALL diets work for weight loss through a caloric deficit. This includes low carb diets, low fat diets, intermittent fasting, etc.
– The reason most people (including the Biggest Loser subjects) regain lost weight is simply because they fail to build the behaviors needed to adhere to their diets in the long term. This means that when they reach their goal, they simply revert back to their past behaviors – i.e. they eat too much and become much less active.
The reason our clients ALWAYS manage to lose weight and keep it off is because we help them change their lifestyles instead of just forcing them to “eat less and move more”
Rumi’s comment on the fact that there is NO reunion is probably taken from Dr Fungs video’s which I just watched one this morning. Its amazing all the hype on the web about who’s a hack and who’s not on diets and shedding tonage stop your meds. Eat properly and exercise, follow up with your doctor if there worth following up with. Allot of money goes into these fallacies of your doomed and will be dependant on meds for life. Unfortunately for some they will be on meds for life but for others they won’t. What works for me may not work for others. If your FREE fat loss ebook is FREE then why not make it so people can download it with out having to provide an email address? Because it’s NOT FREE if you have to provide an email address.
Hello Michael and thanks for your comment,
Regarding the first part of your comment, I’m not sure I understand what you mean. Mind rephrasing please?
Regarding the e-book, it’s free in the sense that it is free of charge.
If you don’t want to be subscribed to Myolean Fitness, you can download the e-book and, simply, unsubscribe immediately after. I promise not to send you any more emails after that or sell/give away your email address. If you really don’t want to go through that one minute process, let me know and I’ll just email the ebook to you! 🙂
Regarding the biggest losers, there was a research and is around the web that after calorie restriction for a long time their metabolic rate diminished so much that after eating normally (but a lot less than when they were obesse) they regain the weight because they are not taking more calories than they are burning. I believe Dr. Fung mentions sometime like “do you think like 90% of the people who takes diets is so morally depleted that they wont stick to the diet” or something like that; point being that diets are hard to endure over time because they are wrong at how the body works and what expects. This is a hot topic.
Hi Abarama,
If you happen to find that study, feel free to share it here so we can critically analyze it! Until then, pretty much every study in the history of ever refutes that fat gain can happen in the absence of a hypocaloric diet.
With regards to why diets fails, it essentially comes down to a combination of factors that negatively impact long-term adherence to the diet. Where Jason is being dishonest (or, at the very least, misinformed) is where he claims that weight regain happens despite subjects adhering to their diets.
Here you go: Persistent metabolic adaptation 6 years after “The Biggest Loser” competition:
http://onlinelibrary.wiley.com/doi/10.1002/oby.21538/full
Thanks for your comment, Scott.
Mind expanding a little please? What exactly is your point?
Dr Fung may believe me when nobody else will. I reduced my food intake below my TEE and did well but by that 10 month mark when most people regain their weight I did too but certainly not because of lack of adherence to my diet. I was very particular about it!
Despite 100% sticking to well below my new TEE (even calorie restricting much less), weight started to increase with other unusual symptoms (probably due to not ovulating; something us women really need for optimal health).
Is it possible, the human body can’t handle continuous weight loss by that 10 month mark. I noticed it applied to all diets too. Is it possible we dieters are telling the truth and maintaining our diets but the body needs to almost starve to lose weight not reduce calories?
Also do you know how many women were on that Minnisota (sp?) starvation diet?
Hello and thank you for your comment.
Regarding the Minnesota Starvation Experiment, it only used male subjects, since the subject pool was men who volunteered to participate in the study as an alternative to military service.
Regarding weight regain, a number of processes and mechanisms underpin it, including homoeostatic, environmental and behavioural ones. I would strongly encourage that you read this study on the topic, which explains the mechanisms that cause weight regain: https://www.nature.com/articles/ijo201559
Essentially, people stop losing weight (and regain it) due to a combination of reasons, including the following:
– a decrease in metabolic rate that is accounted for by the decrease in a person’s body weight
– a further decrease in metabolic rate (or increased metabolic efficiency) that is not accounted for by the decrease in a person’s body weight (we call this metabolic adaptation)
– a decrease in non-exercise activity thermogenesis (NEAT) and in the thermic effect of activity (TEA)
– a decrease in the thermic effect of food (TEF), since you’re now eating less overall, therefore, spending less energy to digest and absorb food
– an increase in energy intake due to changes in hormones that regulate hunger and satiety, as well as due to changes in hedonic reward systems
As you will notice, at the end of the day, weight regain is essentially a result of a sustained positive balance between energy intake and output, i.e. a caloric surplus. Without it, it’s practically impossible to increase your body’s energy stores, as doing this would mean that you are creating energy out of nothing, which goes against the laws of physics.
I hope this helps! 🙂
P.S. if you have data (food diaries and body stats) of your 10-month weight loss and weight regain, I would happily take a look to help you identify what may have gone wrong! You can send these to info@myoleanfitness.com
You are mixing up his argument of changes in ‘BODY FAT’ vs WEIGHT LOSS. I don’t see anywhere that you talk about body fat reduction, just weight loss. As a doctor he only sees those with severe type 2 diabetes and has succesful cured people with his methods. Have you done the same? I agree with you on weight loss (CICO) but he’s going a steps deeper than just weight loss.
Hi Brendon, thanks for your comment.
It’s important to note that, in overweight/obese people, body weight changes are very indicative of fat loss changes. In normal weight people, on the other hand, this is not necessarily the case.
Regarding the rest of your comment, I think you are missing the point of the article.
If you give it another read, you’ll notice that we are tackling specific points that Jason makes, for example his claims regarding metabolic rate changes in response to over and under-feeding, as well as the real cause of weight (and fat) regain.
I think it’s also worth noting that we are VERY concerned with body composition (not just body weight) – note that the entire website is concerned with training and nutrition practices for building muscle and losing fat 🙂
Great article.
I see you have a few here that will never listen..thats a shame.
I was in an facebook Ifasting group and I actually did my first post with the graphic at the top of this article. 🙂
And the insanity started..
The main cheer leader was dancing around mocking me..
I let him..
I kept asking to be shown any “diet” with any macro combination..that did not need a caloric restriction component to lower body weight.
So..their”Calories dont matter..Fung is King”..big mouth posted a link and gave me another lecture.
The link showed a caloric restricted eating plan..and how it effected weight loss and how it effected the endocrine system.
When I pointed out that he had just supported my argument..and not his own..he came back with “you don`t understand how the endocrine system works man”.
Seriously..people are that dim..
Hey Mike and thanks for your comment.
Yep, like they have the slightest clue on how the endocrine system works!
Man, you should see the hateful comments and messages we get from Jason’s followers haha 🙂
At the end of the day, all we can do is give it our best to spread good, unbiased, evidence-based information. Unfortunately we can’t save everyone.
Keep fighting the good fight man!
I’ve followed Dr. Fung’s teachings and am losing a pound a day. Never have I had this kind of weight loss before. I eat two huge nutritionally packed meals twice a day within a 16/8 or 20/4 hr period. I havent felt this healthy in years. Im now down 20 lbs. Your not going to lose weight munching carrots and celery every few hours. Its the fasting, increasing my fats, and lowering carbs so Im converting my body to burn fat stores.
Schools, nutritionists, the government all push us to eat 3 meals a day and healthy snacks. Therefore our bodies never burn fat stores because the glycogen is constantly coming in. Also when your glycogen depletes then hunger pangs kick in again.
So people grab another snack. So you can wave the reduced calorie flag all you want but there is much more to successful weight loss than that.
Thanks for your comment, Christine, and congratulations on your progress! Keep up the great work! 🙂
Okay, so according to a large body of scientific literature, such as this 2016 systematic review and meta analysis (https://www.nature.com/articles/ejcn2015195) (i.e. a study of studies), fat and weight loss are the results of a caloric deficit.
This means that intermittent fasting approaches work for fat loss by helping people eat less overall.
Here’s a quote from the study above:
“Results:
All studies reported significant weight loss for intermittent energy restriction groups. Average weight loss was approximately 0.2–0.8 kg per week. Intermittent energy restriction resulted in comparable weight loss to daily energy restriction when overall energy restriction remained similar between diets. The majority of studies that reported body composition outcomes have shown equal efficacy for fat mass, fat-free mass and waist circumference.
Conclusions:
Weight loss was achieved in overweight and obese adults following intermittent energy restriction and this loss was comparable to a daily energy restriction diet. Intermittent energy restriction may be an effective alternative strategy for health practitioners to promote weight loss for selected overweight and obese people.”
Thankfully, government recommendations and dietitians are starting to catch up with the research, and some are now also recommending intermittent fasting approaches!
We also have several of our clients doing IF, by the way! For some, IF approaches work extremely well!
Regarding Jason Fung, you’ll notice that we are responding to specific unsupported claims he is making regarding BMR changes in response to changes in energy intake, as well as to the causes of weight regain, and not to the claim that IF works for weight loss – we actually agree with that! 🙂
Thanks again!
P.S. here’s a quote from one of our articles (https://www.myoleanfitness.com/10-weight-loss-tips-dieting/):
“Seriously, stop eating every two hours! It doesn’t increase your metabolism or help with fat loss.
In our experience, eating that frequently not only isn’t better, but is usually worse for weight loss, since:
1. it results in many tiny meals of 200 calories each, which never leave you satisfied.
2. it makes you think about food ALL DAY LONG.
3. it’s impractical and a major pain in the butt. I mean, who wants to have to eat every 2 hours at work?
And to the registered dietitians out there: for crying out loud, stop making meal plans with 8 meals per day for your clients! Shame on you. You should know better.”
So… If intermittent fasting works too reduce body fat because it restricts calorie intake… Why does it still work to reduce body fat when you don’t restrict calories?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2645638/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5064803/
Hi Dave and thank you for your comment.
Okay so let’s take a closer look at the studies you linked to:
The Moro et al. study is a pretty good one, actually! However, take a look at the dietary intake of each group. You’ll notice that the TRF group was getting 175 calories fewer than the ND group. Over the 8-week period that comes out to around 9,800 calories, which perfectly explains the 1kg difference in fat loss between the groups.
The Stote et al study is a really small (n=8) pilot study, which suffers from a few problems, including the lack of stringent dietary control for the 3-meal/day group, the use of BIA to assess body composition (which can be as off as 8% points up or down), the timing of the body composition assessment (morning for 1-meal/day group, evening for the 3-meals/day group), and the lack of physical activity reporting. Overall, I wouldn’t pay much attention to this small pilot trial, especially since we have multiple larger, better-designed RCTs, as well as systematic reviews and meta analyses.
Hope this helps!
“I’ve followed Dr. Fung’s teachings and am losing a pound a day. Never have I had this kind of weight loss before. I eat two huge nutritionally packed meals twice a day within a 16/8 or 20/4 hr period. “
Advertroll(TM) Alert 🙂
Anyway..Pure BS.
I would lose that amount IF I was water fasting and nothing else.
yet due to fungmagic..you can equal that..???
“Its the fasting, increasing my fats, and lowering carbs so Im converting my body to burn fat stores.”
I have fasted off and on for over 28 years..there is little you can tell me what fasting can or cannot do.
If your increasing your fats so much..then your burning off dietary fat and not your bodies fat per se…
“So you can wave the reduced calorie flag all you want but there is much more to successful weight loss than that.”
“we” know that.
Your bizarre hand waving aside…the basis is caloric restriction..
Excellent article, thanks for the breakdown. I just read a post by Dr. Fung on Cancer research, and not only was he snarky and snide, but very mistaken on the facts. I’ve been trying to track down his credentials and review his previous work, but unfortunately his SEO is very good and it took me a while to find anything critical. Looks like he’s branching out. Anyway, this is a great quick review of the science, keep using it for good; we need it!
Thanks for your comment and for your kind words, Josh!
Jason is, essentially, a nephrologist and self-proclaimed nutrition expert, so I could imagine how he could also be completely wrong about a topic as complex as cancer.
Unfortunately, it’s easier to fool people than to convince them they’ve been fooled by a quacky internet doctor. Let’s keep fighting the good fight, though!
This article was a very welcome breath of fresh air!
I’ve never managed to get through reading a single article by Fung without feeling uncomfortable at some point.
The frequent spelling mistakes and poor grammar seem unimportant on the surface.
The regular sarcasm perhaps is more important – it makes me question his character. I enjoy a bit of sarcasm, but the way he does it, and the subjects he does it with, reveal his propensity for bias and dismissal of data that doesn’t fit his worldview.
And that leads to my biggest problem with him: He is very dismissive of real science when it doesn’t fit his ideas, and will cherry-pick and even make statements which are patently untrue.
It’s a pity because some of what he writes makes sense, and some of what he suggests can help people get healthy. But all it takes is one bit of overt bias, or falsehood, and that completely destroys his self-assumed position as someone who can be relied upon to disseminate scientific information for the masses.
Hello AJ and thanks for your comment,
Unfortunately, what you are saying is very true. Jason is often aggressively sarcastic in both his writings and videos.
He also (purposely or not) tends to ignore anything that doesn’t fit his biases.
All we can do is to keep spreading good science and hope to reach as many people as possible!
Thanks for the article and sticking to science.
I think the concept of caloric restriction is too simplistic. It’s like saying “any diet works as long as it makes the body get rid of fat stores”. Both concepts don’t explain anything, they are just stating the obvious.
The real question is: Why is the body burning fat? What are the biochemical processes that make the body burn fat?
Saying that with a caloric deficit the body just blindly takes energy from fat is saying that fat stores are not regulated, that the body has no idea how much stores there are. But the body regulates everything.
What I’m saying is: if we find this regulation process, we can adjust our diet and lifestyle to work with this process. This should make the diet much easier and improve adherence.
What is your take on those questions?
Related to those questions is another one of practical importance: Why don’t people adhere to diets?
Is it something biological? Psychological? Social?
Do you have any insight into this? I think knowing the reasons for not adhering, we could make effective counter-measures.
Hello Viktor and thanks for your comment,
I agree with you that caloric restriction as a “solution” to obesity is overly simplistic.
Yes, fat loss is the result of an imbalance between caloric intake and output – this is supported by every well-conducted study in the history of ever. However, this doesn’t explain why people overeat in the first place, why they have trouble losing fat and why most find it so hard to maintain weight loss.
Luckily, we have quite a bit of research on this topic, which suggests that the problem is multi-factorial. Genetic, environmental, physical and emotional factors in combination affect how and why people eat.
In short, our brains are evolutionary programmed to make us want to maintain our body’s energy stores (i.e. fat stores) high, so that we won’t starve to death. In ancient times when food was scarce and humans had to move around much more, this was a vital mechanism for human survival.
Nowadays, with delicious, minimally-processed, high calorie foods being available to us 24/7, 365 days a year and with us not having to move around much (think of a modern office-based job relative to, say, farming a thousand years ago) the evolutionary biological mechanisms that once aimed to keep us from starving are now making us want to overeat and get fat.
The above, combined with emotional issues (for many, eating is a form of stress relief), social issues (“come on man, it’s my birthday, have some cake”), and so on, work in combination to make gaining weight very easy and losing weight very hard.
One comment is not enough to explain all this, so I highly recommend that you get your hands on an amazing book by Dr. Stephan Guyenet on the topic, called “The Hungry Brain”.
I hope this helps!
Thank you very much for the book recommendation! I’m always eager to learn new (and hopefully elegant) ways of looking at nutrition and health. And if the book is as good as the subtitle “Outsmarting the Instincts That Make Us Overeat” suggests, it is exactly what I’m missing. Although I would prefer “Working together with the Instincts…”, though that would sell less copies of the book. 🙂
As to Jason Fung, I read his book and most of his articles. I do agree that his sarcasm and storytelling is often annoying. He also often makes conclusions that seem too hasty, especially if they fit his world view.
But if you can read past those, he actually offers lots of useful information, concepts and advice. In fact I find Jason Fung’s articles still to be one of the best sources on the Internet, despite all his flaws. And having skimmed over your blog I would say you both agree on 80% of what you are saying!
I think you two just disagree on your interpretation, i.e. the concept of weight loss and health. So you both agree on the studies, but interpret them in a way that suits your respective concept. And it’s perfectly fine! We all have this mental bias in our heads.
And if I use my pragmatic mind, I shouldn’t care about which concept you two use as long as his patients and your clients are getting slimmer and healthier!
You’re welcome! 🙂
In general, most fitness professionals agree on the basics: e.g. fat loss is caused by a sustained energy imbalance, we should eat primarily minimally processed foods while also getting enough protein, we should exercise often, and so on.
With Jason, although we agree on many things, we probably disagree on some very basic stuff: for example, we seem to disagree on how people gain fat (energy balance versus the carbohydrate-insulin model of obesity, on how they should best approach weight loss, on why they may plateau and regain weight, etc.
Either way, I agree with you that helping our clients achieve long-terms results is, essentially, what it boils down to! 🙂
How do you address insuline sensetivity?
Hello Mic,
Can you be a little more specific please?
“fewer calories”, not “less calories”. Thank you.
I know I’m late to the party but I just wanted to mention a few observations. As a neuroscientist with an MSc in health sciences (cardiac sciences, specifically), I am decently familiar with the current models of obesity. I agree wholeheartedly with the overarching premise of this article- that weight loss is primarily a CICO deal, and that all diets are structured around that goal. The difficulty comes in when you’re looking at adherence, which you also identified as being a primary driver of post-diet weight management.
The thing that Dr. Fung appears to get right are the focus on mechanisms that underlie hunger cues. A diet is only as good as ones ability to adhere to it, and Fung’s enthusiasm for keto and IF is partly due to the decreased hunger that goes along with both of those two approaches. He tends to link keto and IF, though adherence to keto is poor due to a host of other factors, notably the difficulty of adhering to such a rigid diet. Fasting is also difficult, but over the lifespan, bouts of not eating (which one can customize to when they are most convenient) are easier to incorporate into a daily routine than strict low-carb eating; besides, after 12-24h of a fast, hunger lessens significantly, making this a more tolerable way to restrict calories generally. Also, it allows for carbohydrates during non-fasting times, and since it’s less restrictive, it is generally easier to handle long term. Keto is therefore harder to maintain, while IF offers many of the same benefits but with added flexibility.
The problem with Dr. Fung’s preferred diet model of keto are twofold: 1- he disregards other information that does not fit his viewpoint that keto is superior and carbs will always cause a tendency to overeat (they do up-regulate hunger signals, but some people may feel better on a carb-inclusive diet, which he never mentions). This brings me to 2- the fact that, at its core, a keto diet is typically unsustainable in the long run. In a society that still largely eats carbs, virtually eliminating that entire food group is incredibly difficult as a “forever” diet plan. Most people who start the keto diet tend to drop off around 6-8 weeks. Though it may work exceptionally well for some people (and it is incredibly well-suited for insulin insensitivity and metabolic syndrome, two disorders out of many which are common to obesity), it is extremely hard to maintain. Dr. Fung doesn’t seem to appreciate how difficult it can really be to adhere to, and often has a “if you’re having problems, you’re doing it wrong” approach which is unhelpful.
To sum up, I think that Dr. Fung is well-researched about the endocrine theory of obesity, and how to re-calibrate it via IF to lower hunger cues. The problems crop up with asserting that the keto diet is the best eating plan- it’s marginally superior to other diets only in some areas and is often hard to put into practice. This point about adherence absolutely should be acknowledged by him. At that point, suddenly all of the diets on your chart become feasible to discuss depending on individual preference and metabolic response. Dr. Fung, with his built-in audience and years of education, could admit that other diet types work and try to integrate them into his practice and advice blogs, even if he openly prefers keto. Neglecting to mention other diet types closes his advice off from other people for whom keto isn’t ideal. He would also not be adding to the friction in the nutrition community by dismissing all non-keto diets.
Sorry about the novel I just wrote! I don’t often comment but I was surprised to see the tone he took in his article, and that sense of superiority and dismissiveness pervades a number of his posts. He’s contributing to misunderstandings about nutrition when obesity is so prevalent and there should be consensus as to what the science has shown, at least. He can help guide the way, not restrict the scientific findings to those he prefers.
Hi Sabrina,
Thanks for your comment!
What can I say? I concur! ☺️?
Funny how you only cherry pick the points that you feel like you can debunk. He addresses the adherence factor “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 patient.”
Hello Justin and thank you for your comment.
Maybe you missed a big part of our article which explains (with supporting research) that people regain weight exactly because of reduced dietary adherence and not despite of it. This is actually one of our biggest objections to Jason’s article – he claims that people regain weight even while adhering to their diet. According to a large body of scientific research (again, cited in the article), this is incorrect.
I hope this clears it up. Thanks again.
I lost 50 lbs and was in the best shape of my life under 10 percent body fat. Then my appetite became completely out of control due to the factors that doctor fung has explained. I simply couldnt adhere to the diet any longer as my metabolism was shot from the weight loss with basic caloric restriction. Losing weight this time around i have lost 75 lbs following a fasting for 20 hours a day routine. Also, my metabolism is working just great and hasnt been affected due to my keeping insulin low throughout the day and the great affects of fasting. Dr. Fung actually mentions in his videos that you can lose weight with caloric restriction but that it is unsustainable long term. He is right, because bmr goes way down and your appetite still is massive and you become hungry all the time.
Hey Aaron,
Thanks for your comment and congrats on losing so much weight!
A few questions I have:
1. How exactly did you measure your Basal Metabolic Rate before and after the weight loss? Indirect calorimetry?
2. How exactly did you measure your body fat percentage?
Also, something worth mentioning is that fasting and low carb dieting work for fat loss through caloric restriction, so it’s probably not a great idea to talk about caloric restriction vs fasting, since they are not separate things! 🙂
Agreed about the appetite. by the way! There is research suggesting to intermittent fasting can help people better adhere to their diet because of increased feelings of satiety. The same goes for ketogenic diets – being in ketosis seems to have appetite suppressing effects that are independent of the higher protein intake usually associated with low carb/ketogenic diets.
So if it’s all about calories, why was I able to consume 4000 to 5000 calories at age 20, weighing 165 trying to gain strength/muscle, and I didn’t gain a pound. Yet in my 40’s, I weigh 226, I restrict to 1800 calories, bike and run 4-7 hours a week and don’t lose a pound?
Ahh the calorie in calorie out math just doesn’t add up.
Hey Tim!
What most likely happened is that you were overestimating your energy intake when you were young and underestimating your energy expenditure.
Now, you are probably underestimating your energy intake and overestimating your expenditure.
This is nothing new, by the way. There’s a lot of research showing that people (including Registered Dietitians) can be VERY off at estimating their energy intake and output.
Check our this study, for example. https://www.nejm.org/doi/full/10.1056/nejm199212313272701 The energy intake reported by the subjects in group 1 was 1028 kcal per day, whereas their actual energy intake was 2081 kcal per day. Yep, subjects reported that they were eat around 1000 calories while they were actually eating double that!
Also, the subjects in group 1 reported the amount of energy they expended in physical activities as being 1022 kcal per day, whereas the actual energy so expended was 771 kcal per day, an overestimation by 251 kcal per day!
We see this happening with clients all the time, by the way, when we analyse their food diaries. Figuring out where they are going wrong and making corrections to their calories and macros ALWAYS results in weight loss! 🙂
In any case, I really hope you reach your goals! If you have any questions or you think I may be able to help, please shoot me an email.
Thanks again,
Antonis
Well, I think you are both right and it depends on where in the spectrum of weight/fat loss you apply each technique and the desired outcome. For some, myself included, insulin hyposensitivity may be a driving factor, others inactivity or both, yet others – who knows. There are general physiological truths that apply to everyone but even so-called studies are questionable b/c hardly anyone will volunteer to be monitored around the clock for an extended time to guarantee accuracy of the results so ehh, take what you can from studies and throw the rest in the crapper. I come at the subject from a pessimistic perspective that: A) most people like to be heard B) those that are dogmatic to one point are usually making a mountain out of a mole hill and capitalizing somehow C) there is a grain of truth in all of it. So does starving (fasting) work?Sure, duh, but you don’t hit those fat stores in 12-16 hours so if that’s what you’re doing (like I did) then intermittent fasting is likely calorie reduction anyway. I think Fung points that out-sounds familiar to me but it’s common sense (okay, 5 college degrees for my common sense but probably not needed). If fasting for longer periods then yes, you probably burn fat so some methods of long fasting do work but then you got to consider your lifestyle and if fat loss is your hobby. If not, then fasting all the time probably isn’t going to work–you will eventually die. Otherwise, you will have to keep your calories lower than your expenditure…obviously. Either way, it opens your eyes to what you eat, when you eat, why you eat, and your “real” objectives and I believe that’s the key from both philosophies…be aware of the consequences of what you put in your mouth or don’t and why you choose what you did. So I’m in both camps and neither but I appreciate the information, and I TOTALLY agree on compliance (because human nature is to NOT stick with what is good but what is easiest, for you).
Hey Gary and thanks for your comment.
I’m happy we agree on at least a few things! 🙂
Dr FUNGus advocates a low protein diet……..that alone should discredit the fungus………the CRON diet has been around a long time…….google the 100 yr diet or something like that…calorie restricted optimal nutrition
google roy walford
Roy Lee Walford, M. D. (June 29, 1924 – April 27, 2004) was a pioneer in the field of caloric restriction. He died at age 79 of respiratory failure as a complication of amyotrophic lateral sclerosis (commonly known as Lou Gehrig’s or motor neurone disease). He was a leading advocate of calorie restriction as a method of life extension and health improvement
Some thought about Fung:
1. He actually says ONCE in his book that a person’s first line of defense should be three meals a day, no snacks. It is ludicrous to say that the country has gotten fat on three meals. It was not until snacks became so important that obesity took off, though there are multiple factors. Why doesn’t he push that first and foremost and have people move on after that is established and has not proven effective enough?
2. He gives little good explanation, in my mind anyway, why people in the Blue Zones have such a long health span eating so many starches. Not why all starch eaters- such as the pasta-eating Italians- aren’t all obese. Or diabetic. How about portion sizes? Italians don’t eat huge plates of pasta at a meal. It’s more like a cup or less.
3. He should have been honest and called his first book The Diabetes Code, but there is much less money and sexiness in diebetes than in the Holy Grail of fat loss.
4. He should have to report his REAL results with ALL patients, not just the purported successes. I believe his results are darn impressive and noteworthy, but he does not bat 1000.
5 I would love to see the weekly calorie logs of people doing 24- and 36-hour fasts, then eating three balances meals, as his chart shows they should in his book. I can’t believe they are not eating fewer calories overall. I’d be very doubtful that the weight loss can be attributed solely to the fasting, though some of the other effects may.
6. For anyone who HAS stopped eating (not me, but I sympathize) in a desperate attempt to lose weight, and not been able to maintain any loss because of inordinate rebound urges to eat, it is so insulting to have him talk about his child advocating that people just stop eating, as if that’s really all it would take.
7. His approach will likely help a great number of people but, as nearly all such programs, will hardly make a dent in the overweight/obesity rate in the United States. If it has a 10% success rate of adherers after five years, that would be a big jump, but still a drop in the bucket.
What is your opinion on reducing caloric intake by increased exercise? So eating only when hungry, eating healthy, not being full, and instead of restricting nutritional needs, walking/dancing/etc more. I have no opinion on this, so I’m throwing it out there for debate. Been trying to help cure my husband’s diabetes for a decade with no luck and that’s how I ended up here.
Hey Samantha,
In general, while exercise is great for general health and to help spare lean body mass, improve bone mineral density, etc., it’s probably not enough on its own for weight loss, partly because 2-4 weekly exercise sessions don’t burn THAT many calories, and partly because exercise can sometimes increase hunger (so people end up eating more and compensate for the energy expended). Of course, eating only when hungry, eating healthy, etc., will probably result in eating fewer calories as well, so even if it’s not “purposeful” caloric reduction, it still is caloric reduction 🙂
Overall, a mixture of caloric restriction (while, of course, making healthy food choices, improving relationship with food, etc.) and exercise is best!
Happy to find this article. Seems to me the diet industry is desperate to attack the calorie model to sell their books and supplements.
I read Fung’s page and found it misleading at best. He quote a study as showing that alternate day fasting (ADF) showed no lean body mass loss. I thought that sounded unlikely. But he is quoted all over the net on it. So I got the study and the graph clearly shows 5lb of weightloss, of which 1.5 is fat free body mass! The study does use confusing wording stating no FFBM loss compared to control,. It as the graph showed, thats not the same thing.
Now either Dr Fung is too stupid to understand a graph OR he knows it’s wrong but thinks we are too stupid to check.
Good catch!
I’ve actually caught Dr. Fung on twitter trying to disprove energy balance by sharing a study that clearly showed that fat loss is the result of a caloric deficit!
Its great to see you are responding to comments and defending your positions. My problem is that there is so much misinformation. Dr. Fung seems to be a reliable source of information due to his background. For good measure I google his credibility and stumbled across this post.
I am a 350lb guy that diets when I get paranoid that I will get diabetes bringing my weight down to ~280lbs. Then it starts to get to me. My bloodwork turns normal, I am more energetic but a lifetime of food obsession as well as food as a crucial component of my identity I end up falling of the wagon and go back to being the 350lb guy. THis has happened for the past 5 years. Every fad diet out there has its positives and negatives. How do I know who to go to and who to trust and where my bible is? If I can’t trust a physician like Dr. Fung, why can I trust my own physician. I can read, but I don’t have the medical training to decide what is right and what is wrong. And the person who does (Dr. Fung in this case) is not reliable. I just don’t want diabetes, kidney/liver disease and heart disease.
I hate money in research!
Hello Omar and thank you for your comment.
I understand your point of view and can empathize, since I’m facing the exact same issue in other aspects of my life. For example, when two car mechanics give me a different opinion on what’s wrong with my car, I am simply lacking the knowledge to know who is right or wrong. The same goes in most aspects of my life, by the way, since one can only specialize in a couple of things.
With regard to physicians, I would generally advise against relying on them for nutrition information, since they generally don’t get much education on nutrition and obesity. Instead, you should probably listen to Registered Dietitians for nutrition advice. This should help drive the point better: https://www.facebook.com/myoleanfitness/photos/a.1581829325221047/2340446669359305/?type=3&theater
Also a heads up: Dr. Fung is a nephrologist, so his education background really has nothing to do with nutrition for managing obesity.
Regarding how to separate good and bad nutrition information, that’s pretty tricky. In general, I think that systematic reviews and position papers are a good source of “summed up” information.
For example, here is a recent position stand by the International Society of Sports Nutrition on diets for improving body composition: https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0174-y
You’ll notice that, as per the paper, there are no “good” and “bad” foods, meal frequencies, macronutrient compositions, etc. This kind of black or white thinking is a characteristic of charlatans, so look out for it!
Hope this helps.
CICO = drink only colas and eat chocolates. But count the calories and let me know.
Thanks for your comment. I recommend giving this article on CICO a read: https://www.myoleanfitness.com/cico-evidence-based-truth/
Your main point is that all diets that work rely on the CICO model at the core. You try to refute people who claim this isn’t true (like Dr. Fung). I haven’t chosen a team but I’m trying to figure out what’s most plausible. While I can agree that Dr. Fung makes some overly confident claims (sometimes based on very old studies, which I find a bit odd) and probably tries to highlight his successes for the benefit of the “message” he’s sellling, he seems to make more sense to me that many others.
I would almost be tempted to believe your claim about CICO being at the core of all “diets” except for one thing that seems hard to ignore, and that you also don’t address clearly: it simply HAS to be the case that (as Dr. Fung often says) eating 500 kcal of nuts (for example) is not the same thing as eating 500 kcal of cake (purely in terms of fat gain/loss – of course we’re not talking about overall health). The claim that in one case insulin spikes and in the other not certainly seems plausible. And everyone agrees that insulin plays a large role in fat storage and burning. Doesn’t that thought alone already suggest that surely the story is more complicated than CICO? I know you’re not claiming that it doesn’t matter what we eat, because of course nuts are healthier than cake – but you do seem to be implying that all fat loss methods – no matter how (un)healthy – ultimately rely on CICO. While this seems plausible at first glance, I think it gets suddenly complicated (or maybe even falls apart) as soon as you remember that certain foods are processed differently than others (by different organs, using different chemical processes and having different outcomes). Doesn’t this realization *alone* already put the CICO model on shaky ground? Surely it MUST be the case that if I eat 2000 kcal of nuts on one day, I won’t gain as much fat as if I ate 2000 kcal of cake instead? I strongly suspect that the body requires more energy to process the nuts than the cake, and will preferentially store the “extra energy” in the cake as fat – but not necessarily the for the nuts. Another possibility for “extra energy” – besides being stored – is to simply be excreted. I’m just speculating, but I’m just noting that our bodies are “black boxes” that can either “burn” or “store” energy, but rather can activate different mechanisms depending on what comes in.
Like I said – I have no horse in this race, but I’m just trying to use “common sense” to find the weaknesses in your (and Dr. Fung’s) arguments to get closer to the truth. I believe you’re trying to the do the same.
I’d love to know your thoughts on my comments.
Hi Adrian and thank you for your comment.
I think we address your questions regarding CICO here: https://www.myoleanfitness.com/cico-evidence-based-truth/
Give the article and let me know if it helps clear things up 🙂
Hi again, I looked at the article you linked to and – it all seems reasonable to me! Of course it’s true that CICO has to work at the most basic level. Where most people get lost is in understanding that different kinds of foods effectively cause your body to become a different “kind” of machine (activating different metabolic pathways and burning energy in different ways), and so it’s NOT true that eating 100 kcal of twinkies has the same effect on your body (even in terms of fat loss/gain) as eating 100 kcal of veggies. I always interpreted Dr. Fung’s main argument as being “yes of course CICO, *but* it’s not a useful concept when trying to understand diabetes or weight loss”. But you may be right that he’s said some irrational things. Nonetheless, so far I haven’t found any good reason to completely mistrust him either.
GREAT POINT AND QUESTION, ADRIAN. I too would like a very specific answer to “the case that eating 500 kcal of nuts (for example) is not the same thing as eating 500 kcal of cake (purely in terms of fat gain/loss – of course we’re not talking about overall health). The claim that in one case insulin spikes and in the other not certainly seems plausible. And everyone agrees that insulin plays a large role in fat storage and burning.”
I feel answers to this question are always kind of half-handed and then dismissed. Responses such as “Can you be more specific with your question” asking you to “name your source” or simply posting links noting very outdated studies seem to be the normal dismissal. Like you, I don’t subscribe entirely to either camp, but am trying to understand for my own improvement. The question is extremely relevant. If a Twinkie spikes insulin, but nuts do not, how are the foods (being kind to call a Twinkie a “food”) processed within the body – specifically? And will that lend more evidence to one theory or the other? And another (albeit peripheral) very, very pertinent question to this debacle; Doesn’t Japanese cell biologist Yoshinori Ohsumi’s (2016 Nobel Prize winner in Medicine for his research on how cells recycle and renew their content, via autophagy) work seem to help substantiate how insulin behaves, playing a major role in fat storage/release? I can’t help but think that all sides would put egos aside, and for the benefit of treating obesity (really treating it) try to incorporate and find relevance in Ohsumi’s findings with regard to insulin and caloric deficit dieting? Whether or not a person CHOOSES to fail because they want that Twinkie doesn’t really play in to the fact that if they had disciplined themselves, they may (or may not) have enjoyed better results by manipulating insulin levels with controlling processed carbs?
Hi Carl and thank you for your comment.
I think the problem with just looking at the insulin response to a meal (and one of the reasons I think Dr. Fung does a good job at misleading people) is that it’s myopic, in that you’re only looking at acute substrate utilization and storage rather than at the overall picture.
So, yes, high-GI foods cause larger increases in insulin, and insulin acutely inhibits lipolysis (fat breakdown) and stimulates lipogenesis (fat formation).
However, there’s a difference between fat burning (or storage), and net body fat loss (or gain).
The basic argument of Dr. Fung (and a few other proponents of the CIM of obesity) is that fat gain is the result of increases in insulin per se. However, we have a pretty huge body of research which suggests that, although highly refined foods contribute towards obesity, they do that because they result in a positive energy balance, not because of insulin per se.
You’re talking about “outdated studies”, but they are not outdated at all. In fact, the newest research has left pretty much no room for doubt that the carbohydrate-insulin model of obesity is just incorrect.
Here’s a quote from a recent (2018) paper on the topic:
Although refined carbohydrate may contribute to the development of obesity, and carbohydrate restriction can result in body fat loss, the Carbohydrate-Insulin Model (CIM) is not necessarily the underlying mechanism… …Although it is plausible that variables related to insulin signaling could be involved in obesity pathogenesis, the hypothesis that carbohydrate stimulates insulin secretion is the primary cause of common obesity via direct effects on adipocytes is difficult to reconcile with current evidence.”
Link: https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2686143
P.S. I know that it’s sometimes difficult to have a great conversation with this back-and-forth in the comment section, so, if you want, I’m open to doing a Skype call to discuss! 🙂
Antonis
In my last post, of course I meant to write that “our bodies are *not* “black boxes”…”. I accidentally left the “not” out.
Great thread with lots of great information. I would agree that Fung steps beyond the current data but what he does do is draw attention to something that is not thought about frequently when thinking about dieting. As you have pointed out on your site when you weigh more your BMR is higher. As you lose weight you need to adjust your calorie intake to maintain a deficit. That makes perfect sense from the calories in calories out perspective. But that is only a part of the story. think about people that can maintain a low BMI despite eating like a horse/whatever they like. Why can they eat more? If you follow the CICO argument they MUST be burning more calories. This is what Fung is arguing, CICO is part of the picture because it has to be just not the full picture. You cannot ignore thermodynamics and no one is exempt but there are people out there can can simply burn up the excess fuel. What is the difference? Likely some complex combination of genetics / environmental influences that change hormonal signaling that controls metabolism. This is where Fung steps off into making unsubstantiated claims. I found his book interesting until he was so certain. He can THEORIZE but should not be making causal statements with out proper controlled studies when dealing with something this complicated. As a physician he should understand this.
As others have pointed out I have weighed my food with a food scale for months and have had the diary tracker showing a consistent deficit and have only lost a few pounds despite what a traditional calorie based model would predict. This is not an isolated story unless as you are implying people on failed diets are actually just non-compliant. When I stopped ingesting foods that were likely to spike insulin I saw a consistent weight loss despite maintaining the same calorie intake. Of course this is an n=1 and does not mean anything on the population level…
Coming back to Fung, I do not agree with calling him a quak. He is an MD and a nephrologist who treats type II diabetes and obesity. This actually makes him an expert and while expert opinion needs to be challenged I believe it should be respectful and avoid ad hominem attacks despite what your opponent is slinging.
Thank you for your comment, David.
I definitely agree with most of your points.
A couple of things I’d like to comment on:
1. “Think about people that can maintain a low BMI despite eating like a horse/whatever they like. Why can they eat more?”
I’m glad you asked this. There is quite a bit of research suggesting that people who seem like they can eat a lot without gaining weight have a subconscious increase in Non-Exercise Activity Thermogenesis in response to overfeeding. Here’s a quote from a relevant paper: “In summary, these data underscore the highly variable individual compensatory responses with regard to adaptive thermogenesis to overfeeding. From Levine et al., supportive evidence is provided for the susceptibility to gain body mass under standardized overfeeding conditions and identifies an individual’s ability to adapt NEAT as one critical determinant (16, 29, 43). In accordance with findings of other overfeeding studies (reviewed in (57)), adaptations in thermogenesis by changes in NEAT observed between individuals may be an important explanation for why some individuals are particularly susceptible, or resistant, to weight gain.” https://www.ncbi.nlm.nih.gov/books/NBK279077/
“Coming back to Fung, I do not agree with calling him a quak. He is an MD and a nephrologist who treats type II diabetes and obesity. This actually makes him an expert and while expert opinion needs to be challenged I believe it should be respectful and avoid ad hominem attacks despite what your opponent is slinging.”
I agree that discussion has to be respectful, and I generally try to keep it clean. However, it’s very hard to keep it entirely clean when Dr. Fung calls people who disagree with him “stupid” in his YouTube videos, especially when the amount of scientific evidence that go contrary to his claims is so huge. In short, I don’t think anyone “deserves” respect unconditionally.
I’m eating more calories than I ever have, same foods as before, same amount of activity but doing intermittent fasting and I’m losing weight. How does your theory explain this? I do agree that a calorie deficit would work very well for some people, but everyone’s bodies work differently. It never worked for me, only significantly lowered my energy levels.
Hi Lauren and thank you for your comment.
I understand what you’re saying. What’s probably happening is that you think you’re eating the same as before, but you’re eating less, because IF allows less opportunity for you to eat. We see this a lot in IF research: subjects over-report calorie intake (i.e. they report eating more than they do – not on purpose, of course). This is actually the main reason why IF helps people lose weight! In short: IF > decreased opportunity to eat > eat less > caloric deficit > weight loss.
If you’d like to discuss more, feel free to email us and we can arrange a Skype call! 🙂
The explanation is that you are not (or more likely, were not) accurately measuring your caloric intake.
Thank you, thank you, thank you. I was feeling so alone in the world until I read this web page. Exactly what I keep shouting at deaf ears.
You’re definitely not alone! 😀
I think your comments and analysis are spot on. And you do say in your article that the best diet is the one that can be adhered to. I have found all of theSe things to be true in my own experience. I have never been severely overweight but I do think I have underlying insulin resistance and appreciate the things I have learned through trying low-carb and ketogenic diet s in regards to how my body reacts to certain things . I have tried many different diets over the course of many years. I do believe that insulin has a great part in weight loss but that sensitivity and blood sugar control can be achieved in many different ways. Eating whole foods I think is the one rule we all can agree on and from there people can adjust but ultimately it does come down to moving more and eating less for weight loss. . There is no magic macro nutrient. Having said that, each person has to determine what works best for their body and their lifestyle. Diets are tools not magic.
Thanks for your comment, Amy! Spot on! 🙂
I have lost 100kg in the last 2 years, my only methods were calorie deficit and IF for managing my habit of snacking. I stopped eating after dinner till breakfast the next day, the hours I fasted were not as important to me as I used it as a tool to break a bad habit.
I walk for exercise now but most of my weight loss was purely down to eating less and as healthy as possible with the odd treat thrown in.
I have been maintaining my weight now for 6 months.
Wow, way to go!! 🙂
As someone who really likes to consider the science behind arguments made, after I read “The Obesity Code”, I wanted to find a solid counter argument.
Sadly, this one, like many others is veiled in what appears to be fact, but falls short because it doesn’t seem to debunk anything. I’m not a scientist but I am able to reason logically and the arguments above simply don’t hold up. Perhaps I’m missing something and I would love to hear an alternate, science based argument.
First, just to be clear – the only point that I find relevant in Dr. Fung’s book is the theory behind insulin and insulin resistance. In this article and in the commentary that follows, the author seems to assume that simply because he or she’s “debunked” two or three anecdotal points from the book that this somehow completely invalidates Dr. Fung’s primary conclusion that insulin resistance causes weight gain. This is simply false. I am sure there is a term for such a thing in the science community but just because you’ve proven that he misquoted a figure (15% vs 40%, for example, both of which are actually negative) does not mean that you’ve somehow proven his theory wrong.
From my reading of the book, Dr. Fung essentially argues that when you eat is just as important as what you eat. He specifically argues (and seems to provide studies) that insulin release is tied to weight gain and for that reason he believes that intermittent fasting is superior to other methods when it comes to weight loss.
Unfortunately, nothing that you’ve presented seems to debunk that. Can you provide that information? Can you show that when you give people insulin they do not gain weight? If that study exists, I’d love to see it.
All of the studies above show, again, that in the short term all diets work. Dr. Fung says the same in his book. I completely would accept the argument that we need more information on IF and we certainly need more information over a much longer period of time to better understand the arguments made on both sides. But to call this an argument that debunks Dr. Fung’s claims based on science is laughable.
Hi Ivana and thank you for your comment,
There is actually a large body of scientific evidence which suggests that insulin sensitivity and insulin release from food are pretty irrelevant for fat loss, and that the primary criterion is, instead, a sustained hypocaloric diet.
Here are some papers:
This study (https://jamanetwork.com/journals/jama/article-abstract/2673150) aimed to determine the effect of a healthy low-fat (HLF) diet vs a healthy low-carbohydrate (HLC) diet on weight change and if genotype pattern or insulin secretion are related to the dietary effects on weight loss. Here are the conclusions: “In this 12-month weight loss diet study, there was no significant difference in weight change between a healthy low-fat diet vs a healthy low-carbohydrate diet, and neither genotype pattern nor baseline insulin secretion was associated with the dietary effects on weight loss. In the context of these 2 common weight loss diet approaches, neither of the 2 hypothesized predisposing factors was helpful in identifying which diet was better for whom.”
Here is another recent study (https://www.sciencedirect.com/science/article/pii/S0026049516300725), which concluded that “These findings suggest that weight loss itself, rather than diet composition, may be the most critical factor for reducing the chronic inflammation that has been suggested to be a key factor in promoting insulin resistance.”
Here’s a recent review on the carbohydrate-insulin model of obesity: “Several logical consequences of this carbohydrate-insulin model of obesity were recently investigated in a pair of carefully controlled inpatient feeding studies whose results failed to support key model predictions. Therefore, important aspects of carbohydrate-insulin model have been experimentally falsified suggesting that the model is too simplistic.” https://pubmed.ncbi.nlm.nih.gov/28074888/
Thanks again for your comment!
Hi,
Thanks for the informative article. I have personally experienced the entire gamut of massive weight gain, massive weight loss, keto, low fat, and currently have been practicing IF (omad). As Leangains says, IF with eating ad-libitum mostly maintains status quo. If you’re not careful, it could even worsen things. This has happened to me – the sense of entitlement with 23 hours of fasting gives you a ridiculously detrimental false security.
So, in that sense IF is no magic.
But, I encourage you to read Peter Attia’s below article.
https://peterattiamd.com/good-science-bad-interpretation/comment-page-5/
As he says CICO is a description and not an explanation. It is an observation that does not provide any clue about what’s working (and what’s not). Its actually fairly useless as a concept, IMO. Why? Because Calories out is a)not easily measurable b)depends on Calories In (kinda like Heisenberg’s uncertainty principle) c) depends on body weight which itself is variable and dependent on CICO equation. On a day to day basis also CICO only provides a very vague high level starting point – Hormones and endocrine system hugely effect that equation and all of this needs to be found for the individual by trial and error.
So while first law of thermodynamics stays – its not very useful. All calories are equal in their energy value. They’re not equal in body’s utilization and hormonal reaction to them.
So Fung’s not that off, honestly. Although personally I am a Lyle Mcdonald fan and a recent follower of Peter Attia.
Hi and thank you for your comment.
I highly encourage you to read our article on CICO, here: https://www.myoleanfitness.com/cico-evidence-based-truth/
Perfect. I also work in the field of weight loss as a qualified doctor and I am particularly interested in helping people with insulin resistance. I get engaged in helping them with meal composition in which carbs a lower, protein is maintained and vegetables are Central. Why does it work? It is a good combination that generates satiety. Which helps with adherence to calorie control. Simple.
Thank for your comment, Rashmi.
Indeed, it’s mind-boggling how so many people don’t get this!
He has explained why even people who follow the diet gain weight in the long term a number of times, there are even videos of lectures about that.
In short, it has to do with metabolic adaptation (exactly what happens to me). You eat less, your body adapts and spends less energy, especially in a high carbs based diet.
Thank you for you comment, Jonas.
Dr. Fung is being misleading, as no study has ever detected weight gain in subjects reducing their calorie intake.
I came here after reading a few Fung books and noticing some inconsistencies – one of which, to add to the collection, is – “calorie deficit does not work long term cause metabolism revs up.” But then shortly after he tells of how gastric bypass causes enforced calorie restriction (calorie deficit) and says that since it is enforced it works long term. Or something like that.
Gastric bypass is more like caloric restriction and not like insulin based / fasting weight loss. (I am sure there is a more accurate way to say this – but the point remains).
While I had low expectations for this article because of my general distrust for similar websites, which attempt to goad you into buying overpriced products you really don’t need or have to use, I can safely say that this article was very informative and reinforces my positions relating to weight loss. After reading your comments and your sources, I finally felt relieved that I have found another source of good information. While not being an RD or having formal education (although I’m considering it!), but still having a deep interest in nutrition and exercise, it frustrates me constantly to see those WITH seemingly reputable backgrounds spread the most common misinformation (usually to sell a product), especially with the creepy cult like comments. I look forward to reading more articles of yours when I do another deep dive into nutrition in the future! Thank you for combatting misinformation in a civil manner (seriously those cult comments were starting to gaslight me). I’m glad I found this hidden gem.
Thank you for the kind words, Richard! It’s great to know people appreciate the hard work we put into our content 🙂