Carbohydrate-insulin model of obesity is false
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Azdak
Posts: 8,281 Member
http://www.nature.com/ejcn/journal/vaop/ncurrent/full/ejcn2016260a.html
This may be more frustrating to present because I can't access the entire article and it is pretty complex.
Here is the abstract:
"The carbohydrate–insulin model of obesity theorizes that diets high in carbohydrate are particularly fattening due to their propensity to elevate insulin secretion. Insulin directs the partitioning of energy toward storage as fat in adipose tissue and away from oxidation by metabolically active tissues and purportedly results in a perceived state of cellular internal starvation. In response, hunger and appetite increases and metabolism is suppressed, thereby promoting the positive energy balance associated with the development 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. This review describes the current state of the carbohydrate–insulin model and the implications of its recent experimental tests."
The takeaway: there is no evidence to indicate that elevated insulin levels from ingesting higher amounts of carbs have any effect on stored body fat INDEPENDENT of energy balance.
This may be more frustrating to present because I can't access the entire article and it is pretty complex.
Here is the abstract:
"The carbohydrate–insulin model of obesity theorizes that diets high in carbohydrate are particularly fattening due to their propensity to elevate insulin secretion. Insulin directs the partitioning of energy toward storage as fat in adipose tissue and away from oxidation by metabolically active tissues and purportedly results in a perceived state of cellular internal starvation. In response, hunger and appetite increases and metabolism is suppressed, thereby promoting the positive energy balance associated with the development 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. This review describes the current state of the carbohydrate–insulin model and the implications of its recent experimental tests."
The takeaway: there is no evidence to indicate that elevated insulin levels from ingesting higher amounts of carbs have any effect on stored body fat INDEPENDENT of energy balance.
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Replies
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As a recent fan of ketogenic diets and fasting, I'm really interested in this topic. I would geek out over this study but the link requires $32 to access the article which I'm not paying.
I'm a bit biased in that I wholeheartedly believe insulin is a growth factor and excess levels lead to weight gain. I don't think it's the only cause of weight gain but it's a major player, IMO. Given those beliefs, I'd like to know exactly what the "refeeding" diet included. How many patients were enrolled? How did they determine insulin is not an independent factor for weight gain? And probably most importantly, who funded this study? I guess I need a lot more info. than what was provided.
I find it interesting at the end of the abstract (but honestly, that wasn't even an abstract, didn't outline the study design or specific results) they state, "Therefore, important aspects of carbohydrate-insulin model have been experimentally falsified suggesting that the model is too simplistic." I'm not 100%clear on what they intended with that statement but I *think* they're just reaffirming their study results which we don't really know. I would apply the same statement to the old CICO model.2 -
Well, if it's Hall referencing his study, wasn't one of the funders NuSI, Gary Taubes' group?
Unless this is a new study that was a follow up to the first one.5 -
As a recent fan of ketogenic diets and fasting, I'm really interested in this topic. I would geek out over this study but the link requires $32 to access the article which I'm not paying.
I'm a bit biased in that I wholeheartedly believe insulin is a growth factor and excess levels lead to weight gain. I don't think it's the only cause of weight gain but it's a major player, IMO. Given those beliefs, I'd like to know exactly what the "refeeding" diet included. How many patients were enrolled? How did they determine insulin is not an independent factor for weight gain? And probably most importantly, who funded this study? I guess I need a lot more info. than what was provided.
I find it interesting at the end of the abstract (but honestly, that wasn't even an abstract, didn't outline the study design or specific results) they state, "Therefore, important aspects of carbohydrate-insulin model have been experimentally falsified suggesting that the model is too simplistic." I'm not 100%clear on what they intended with that statement but I *think* they're just reaffirming their study results which we don't really know. I would apply the same statement to the old CICO model.
How could it be a factor independent of energy balance? If I'm in an energy deficiency, I'm not going to have net fat storage...same in maintenance.
If you look at blue zone regions of the world, their traditional diets tend to be higher carb, moderate protein, and lower fat (not low fat)...if the carbohydrate/insulin model panned out, they wouldn't be "blue zone"...they'd all be obese or over fat.
Insulin is a growth factor which is why when someone is training and bulking, that carbs are king...but they're also in a calorie surplus...
8 -
As a recent fan of ketogenic diets and fasting, I'm really interested in this topic. I would geek out over this study but the link requires $32 to access the article which I'm not paying.
I'm a bit biased in that I wholeheartedly believe insulin is a growth factor and excess levels lead to weight gain. I don't think it's the only cause of weight gain but it's a major player, IMO. Given those beliefs, I'd like to know exactly what the "refeeding" diet included. How many patients were enrolled? How did they determine insulin is not an independent factor for weight gain? And probably most importantly, who funded this study? I guess I need a lot more info. than what was provided.
I find it interesting at the end of the abstract (but honestly, that wasn't even an abstract, didn't outline the study design or specific results) they state, "Therefore, important aspects of carbohydrate-insulin model have been experimentally falsified suggesting that the model is too simplistic." I'm not 100%clear on what they intended with that statement but I *think* they're just reaffirming their study results which we don't really know. I would apply the same statement to the old CICO model.
Re: the bolded - you'd apply the same statement to the laws of thermodynamics?4 -
I can't remember if it was Hall's study or not but I think there's supposed to be a recent study where they injected glucose or insulin or some such intravenously and it had no impact on hunger? I wonder if that's this study.
I'm sure we'll hear more soon.0 -
cwolfman13 wrote: »As a recent fan of ketogenic diets and fasting, I'm really interested in this topic. I would geek out over this study but the link requires $32 to access the article which I'm not paying.
I'm a bit biased in that I wholeheartedly believe insulin is a growth factor and excess levels lead to weight gain. I don't think it's the only cause of weight gain but it's a major player, IMO. Given those beliefs, I'd like to know exactly what the "refeeding" diet included. How many patients were enrolled? How did they determine insulin is not an independent factor for weight gain? And probably most importantly, who funded this study? I guess I need a lot more info. than what was provided.
I find it interesting at the end of the abstract (but honestly, that wasn't even an abstract, didn't outline the study design or specific results) they state, "Therefore, important aspects of carbohydrate-insulin model have been experimentally falsified suggesting that the model is too simplistic." I'm not 100%clear on what they intended with that statement but I *think* they're just reaffirming their study results which we don't really know. I would apply the same statement to the old CICO model.
How could it be a factor independent of energy balance? If I'm in an energy deficiency, I'm not going to have net fat storage...same in maintenance.
If you look at blue zone regions of the world, their traditional diets tend to be higher carb, moderate protein, and lower fat (not low fat)...if the carbohydrate/insulin model panned out, they wouldn't be "blue zone"...they'd all be obese or over fat.
Insulin is a growth factor which is why when someone is training and bulking, that carbs are king...but they're also in a calorie surplus...
The carbohydrate-insulin theory of obesity discounted the role of energy balance in any of these equations.
That's the whole problem with it. The theory rested solely on the role of insulin causing fat storage.
The only mention that I can recall off the top of my head in the whole thing about energy had to do with increased energy expenditure due to fat oxidation if eating a high fat diet. I believe that was supposed to be the mechanism for weight loss.
From what I can also recall, that increased energy expenditure effect only lasted three weeks.
My recall might be faulty here.0 -
AlabasterVerve wrote: »I can't remember if it was Hall's study or not but I think there's supposed to be a recent study where they injected glucose or insulin or some such intravenously and it had no impact on hunger? I wonder if that's this study.
I'm sure we'll hear more soon.
Hall did say he was going to come out with more later on the whole hunger aspect when that initial study was released. You might be on to something here.0 -
GottaBurnEmAll wrote: »cwolfman13 wrote: »As a recent fan of ketogenic diets and fasting, I'm really interested in this topic. I would geek out over this study but the link requires $32 to access the article which I'm not paying.
I'm a bit biased in that I wholeheartedly believe insulin is a growth factor and excess levels lead to weight gain. I don't think it's the only cause of weight gain but it's a major player, IMO. Given those beliefs, I'd like to know exactly what the "refeeding" diet included. How many patients were enrolled? How did they determine insulin is not an independent factor for weight gain? And probably most importantly, who funded this study? I guess I need a lot more info. than what was provided.
I find it interesting at the end of the abstract (but honestly, that wasn't even an abstract, didn't outline the study design or specific results) they state, "Therefore, important aspects of carbohydrate-insulin model have been experimentally falsified suggesting that the model is too simplistic." I'm not 100%clear on what they intended with that statement but I *think* they're just reaffirming their study results which we don't really know. I would apply the same statement to the old CICO model.
How could it be a factor independent of energy balance? If I'm in an energy deficiency, I'm not going to have net fat storage...same in maintenance.
If you look at blue zone regions of the world, their traditional diets tend to be higher carb, moderate protein, and lower fat (not low fat)...if the carbohydrate/insulin model panned out, they wouldn't be "blue zone"...they'd all be obese or over fat.
Insulin is a growth factor which is why when someone is training and bulking, that carbs are king...but they're also in a calorie surplus...
The carbohydrate-insulin theory of obesity discounted the role of energy balance in any of these equations.
That's the whole problem with it. The theory rested solely on the role of insulin causing fat storage.
The only mention that I can recall off the top of my head in the whole thing about energy had to do with increased energy expenditure due to fat oxidation if eating a high fat diet. I believe that was supposed to be the mechanism for weight loss.
From what I can also recall, that increased energy expenditure effect only lasted three weeks.
My recall might be faulty here.
I believe that was already addressed by Krieger in a previous research review: http://weightology.net/weightologyweekly/index.php/free-content/free-content/volume-1-issue-7-insulin-and-thinking-better/insulin-an-undeserved-bad-reputation/
tl;dr - insulinz iz not da debilz.4 -
GottaBurnEmAll wrote: »cwolfman13 wrote: »As a recent fan of ketogenic diets and fasting, I'm really interested in this topic. I would geek out over this study but the link requires $32 to access the article which I'm not paying.
I'm a bit biased in that I wholeheartedly believe insulin is a growth factor and excess levels lead to weight gain. I don't think it's the only cause of weight gain but it's a major player, IMO. Given those beliefs, I'd like to know exactly what the "refeeding" diet included. How many patients were enrolled? How did they determine insulin is not an independent factor for weight gain? And probably most importantly, who funded this study? I guess I need a lot more info. than what was provided.
I find it interesting at the end of the abstract (but honestly, that wasn't even an abstract, didn't outline the study design or specific results) they state, "Therefore, important aspects of carbohydrate-insulin model have been experimentally falsified suggesting that the model is too simplistic." I'm not 100%clear on what they intended with that statement but I *think* they're just reaffirming their study results which we don't really know. I would apply the same statement to the old CICO model.
How could it be a factor independent of energy balance? If I'm in an energy deficiency, I'm not going to have net fat storage...same in maintenance.
If you look at blue zone regions of the world, their traditional diets tend to be higher carb, moderate protein, and lower fat (not low fat)...if the carbohydrate/insulin model panned out, they wouldn't be "blue zone"...they'd all be obese or over fat.
Insulin is a growth factor which is why when someone is training and bulking, that carbs are king...but they're also in a calorie surplus...
The carbohydrate-insulin theory of obesity discounted the role of energy balance in any of these equations.
That's the whole problem with it. The theory rested solely on the role of insulin causing fat storage.
The only mention that I can recall off the top of my head in the whole thing about energy had to do with increased energy expenditure due to fat oxidation if eating a high fat diet. I believe that was supposed to be the mechanism for weight loss.
From what I can also recall, that increased energy expenditure effect only lasted three weeks.
My recall might be faulty here.
I believe that was already addressed by Krieger in a previous research review: http://weightology.net/weightologyweekly/index.php/free-content/free-content/volume-1-issue-7-insulin-and-thinking-better/insulin-an-undeserved-bad-reputation/
tl;dr - insulinz iz not da debilz.
Yup. I love that.
I always say that people who say "insulin makes carbs store as fat" are only telling half the story because of what I learned from reading Krieger.0 -
Here's a good explanation of Hall's past 2 studies, especially the second one. There's an interview between him and Yoni Freedhoff included:
http://www.thenutritionwonk.com/single-post/2016/05/02/Is-the-Insulin-Theory-of-Obesity-Over2 -
lemurcat12 wrote: »Here's a good explanation of Hall's past 2 studies, especially the second one. There's an interview between him and Yoni Freedhoff included:
http://www.thenutritionwonk.com/single-post/2016/05/02/Is-the-Insulin-Theory-of-Obesity-Over
So it's still... satiety and energy balance.
Whod've thunk it.
I find the increased EE in the very low fat diet interesting, though. I eat low fat, but I don't think I could go as low as the test subjects did in that first study.2 -
I'm thoroughly convinced that the insulin hypothesis of obesity is 100% false.
The interview with Hall and Freedhoff was great too.
Ultimately, just for anyone reading this who might feel like this is some sort of personal attack on their belief system or their diet -- this doesn't mean AT ALL that low carb dieting is ineffective or bad, it simply means that Taubes is wrong about the insulin hypothesis.
Low carb dieting can still be very effective for some people even though it is still governed by energy balance.12 -
I like Hall, Guyenet, Freedhoff and the rest but I don't believe the insulin hypothesis of obesity is quite as dead and buried as they believe. It just makes so much sense and seemingly fits my experience to a T - a low carb diet shuts down that drive to eat and keep eating like a light switch for me.
I think the hypothesis still has merit and is worth investigating further.The existing paradigm doesn’t work and it’s time for new thinking! The Calories In, Calories Out model states that weight control is simply a matter of eating a bit less, and moving a bit more. Although our modern food environment may offer many temptations, it’s ultimately a question of will power. However, this way of thinking disregards a century of research showing that body weight is controlled more by biology than will power over the long term. Indeed, the obesity epidemic has progressed despite an incessant focus on calorie balance by the government, professional nutrition establishment, and, recently, the food industry (witness the 100 Calorie Pack). To add insult to injury, the conventional model blames people with obesity for failure to control their calorie balance. But if conscious control of calorie balance were so crucial, how did people manage to avoid massive swings in weight before the notion of the calorie was invented a century ago?
Contrary to claim, the Insulin-Carbohydrate model is founded on solid science, as detailed above and summarized here:- The body fights back against calorie restriction, with increased hunger and lower metabolic rate — biological adaptations that make weight loss maintenance progressively more difficult over time.
- Metabolic dysfunction involving fat cells has been definitively shown to precede overeating, at least in some models of obesity.
- Primary hypersinsulinemia promotes calorie storage in adipose tissue, lowers the concentration of calories in the blood stream, triggers overeating, and causes long-term weight gain. In a state of hyperinsulinemia, restriction of food intake may diminish the rate of weight gain, but does not prevent excess adiposity.
- Highly processed carbohydrates cause more insulin secretion, calorie for calorie, than any other food, and are consistently associated with the most weight gain in the best cohort studies [Mozaffarian].
- The highest quality weight loss diet trials — with measures to assure differentiation between treatment groups — show clear advantages of a reduced glycemic load diet compared to a low fat diet.
- Reducing glycemic load appears to attenuate the biological adaptations antagonizing weight loss, including decreased energy expenditure [Pereira, Ebbeling].
Thus, the Insulin-Carbohydrate model argues that calorie restriction causes a state of deprivation in the body, resulting in the hallmarks of starvation: rising hunger and falling energy expenditure. This pushback from the body can be mitigated by diet quality — especially by reducing consumption of highly processed carbohydrates — resulting in long-term weight loss with less difficulty. The Insulin-Carbohydrate model also provides a more plausible explanation than lack of willpower for the poor results of conventional diets (as most people with obesity have a strong desire to achieve lasting weight loss).
Of course, much more research will be needed to reach a full understanding of the etiologies of obesity and individual variability in response to treatment. Until then, we must keep our minds open to new, potentially more effective approaches to the public health crisis of obesity-related disease.
Ludwig0 -
AlabasterVerve wrote: »I can't remember if it was Hall's study or not but I think there's supposed to be a recent study where they injected glucose or insulin or some such intravenously and it had no impact on hunger? I wonder if that's this study.
I'm sure we'll hear more soon.
I think you are referring to this one:
https://www.ncbi.nlm.nih.gov/pubmed/27356203
(K.Hall is not among the authors)0 -
Yesterday I tried to respond to someone on the first page who questioned whether I *really* believed insulin was an independent factor in weight gain but failed (lost my c&p, then forgot...old person's issues).
I believe it's an independent risk factor but that differs from saying it's the exclusive risk factor. Calories matter, sure, but I think we need to acknowledge that we've been lauding the CICO model for weight loss at the exclusion of other factors, for too long. For like 30 years CICO has shown time and again it's not great for maintenance of weight loss. There are human studies that show with a drop in caloric intake, there's a reciprocal drop in metabolic rate.
Maintenance is the key factor to study, not weight loss. People lose weight all sorts of ways but we all know that stat of 90-95% gain it back. Sure, there are a anecdotal reports all over MFP of users doing only CICO, eating anything in moderation and losing weight. However, we should be looking at long term weight loss maintenance instead because that's where we'll spend most of our time (hopefully).
As far as doing a randomized, double-blind clinical trial on thousands of people to determine insulin's role in weight gain, you'll likely not see one. It would require something like an identical twin study where both are the same weight, free of diabiates, eat the same foods but one is injected with insulin and one, saline. That kind of study will never be approved in a responsible nation. So, we rely on vague stats and loads of opinions. I think, then, we really need to figure out who has the most valuable opinion. I look to physicians who have had hundreds and sometimes thousands of patients on low carb, low sugar, some variant of fasting-type diets. I look at their writings, listen to their podcasts, scan the original human studies they cite.
Gah, that was so long but it's based on the frustration of seeing the beating of the CICO drum repeatedly, for decades, with complete disregard for the role sugar and carbs play in our weight and health. (You can thank big food/agriculture lobbyists for that). When I read about people asking, "can I eat (insert high sugar processed food)?" and others respond with "IIFYM" and "no foods are bad"....ugh, I can't even. There are bad foods. Can you eat them? Absolutely. Can you eat them daily? You can but it's a horrible idea.2 -
Not going to quote the entire giant comment, but it again mistakes a law of physics for an diet strategy.
Saying "with a drop in calories there is a drop in metabolic rate" only reinforces that weight loss is a matter of energy balance.
Whether cutting calories only is the best approach is a completely different topic and not what is being discussed at all.
The nutritional aspect of foods, their effects on overall health are--again--excellent discussion topics. But they are again irrelevant to this topic.
The effect of certain foods on satiety and behavior--important to consider, but nothing to do with the topic.
The topic deals with one thing and one thing only--the assertion made by people like Taubes and other low-carbers that insulin can cause a person to gain fat independently of energy balance. And there is little or no direct research to support that assertion.14 -
I'm thoroughly convinced that the insulin hypothesis of obesity is 100% false.
The interview with Hall and Freedhoff was great too.
Ultimately, just for anyone reading this who might feel like this is some sort of personal attack on their belief system or their diet -- this doesn't mean AT ALL that low carb dieting is ineffective or bad, it simply means that Taubes is wrong about the insulin hypothesis.
Low carb dieting can still be very effective for some people even though it is still governed by energy balance.
It's definitely important to separate the two. There are a lot of different strategies one can employ to lose weight. Some of them can be grounded in hard science, some can be Jedi mind tricks. Some can be a mixture of both. Given that CICO is the unifying underlying principle to all weight loss, and given the importance of emotion, psychology, and behavioral factors in this process, I am all in favor of Jedi mind tricks if they get the job done.
The main reason that low carbers attract special attention--right or wrong--is that there tends to be a higher percentage of one-true-faith proselytizers in that group and a tendency to reject science and believe in the he Insulin Fairy. As an eating plan, I don't think it is particularly unhealthy, and it can work as well as any other. For some people with certain metabolic profiles it might even be the best choice.9 -
Editing to break this up:For like 30 years CICO has shown time and again it's not great for maintenance of weight loss. There are human studies that show with a drop in caloric intake, there's a reciprocal drop in metabolic rate.
I don't think this is true at all. Societally calories have gone up and up over the past 30 years. Yes, when you lose weight you need to eat less to maintain it, but that has nothing to do with CICO. Also, yes, there's often a metabolic effect of being overweight and losing weight (although how much and how permanent is to be determined), but again that's not contrary to CICO or supportive of the insulin theory (nor is there evidence that low carbing prevents it).
Are there other kinds of studies you are referring to?Maintenance is the key factor to study, not weight loss. People lose weight all sorts of ways but we all know that stat of 90-95% gain it back.
Because they eat more than they burn again. The issue is the factors that help people not overeat, but that has nothing whatsoever to do with calories in vs. calories out being an accurate explanation or not. They do mean that more is typically needed for many to help with psychological factors (IMO, this is largely about structure). And, as Side Steel said low carbing definitely could be the answer for some. But not because insulin trumps calories.
(Also, there's no evidence that low carbing has a better success rate than any other diet. Might it for you? Sure. Just as 80-10-10 vegan might for someone else.)As far as doing a randomized, double-blind clinical trial on thousands of people to determine insulin's role in weight gain, you'll likely not see one. It would require something like an identical twin study where both are the same weight, free of diabiates, eat the same foods but one is injected with insulin and one, saline.
The Hall study was pretty close -- did you follow my link?
One group ate very low carb and did have a huge decrease in insulin, but that didn't lead to more fat loss.
But sure, if you just want someone to agree with your opinion, you can find a diet guru and podcasts saying that. I like nutrition podcasts and have listened to lots of low carb and paleo leaning ones, as well as lots of plant based, low fat ones. Eh, they all say basically the same thing in support of their own pet ways of eating. I think CICO is what matters and beyond that we have to figure out what works for us to have a sustainable, healthy diet that is calorie-appropriate. (My carbs would likely be considered low by many although they are nowhere near keto.) What I find irresponsible and annoying is to tell people that your way is the only workable way.
One last point before I respond to the complaints about diet advice given on MFP, and an important one -- eating a healthful diet or not has nothing, nothing whatsoever to do with the insulin hypothesis. I hope you understand that. You can eat a very low carb diet with little insulin response that is extremely unhealthful and fails to meet nutrient needs. And, you can eat a very high carb diet that has a much higher insulin response that is nevertheless extremely healthful and easily goes way beyond many nutrient needs (I think this is even easier, but I've played around with WFPB diets). Most "junk" food isn't "carbs!" but about half carb/half fat.
(Response to the "people on MFP don't give the right nutrition advice" in a following post.)3 -
AlabasterVerve wrote: »I like Hall, Guyenet, Freedhoff and the rest but I don't believe the insulin hypothesis of obesity is quite as dead and buried as they believe. It just makes so much sense and seemingly fits my experience to a T - a low carb diet shuts down that drive to eat and keep eating like a light switch for me.
I don't think they are claiming this part of it is disproven, but then I haven't seen the newest study yet. I would consider this separate from the insulin hypothesis (as Freedhoff and Hall explain in the interview I linked, for example).
I do think there likely is an appetite effect in some people, whether it's insulin or something else (I've seen other theories on that).0
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