Anthony Colpo recently posted a discussion of one of my older posts on seed oils and body fat gain (1), which reminded me that I need to revisit the idea. As my knowledge of obesity and metabolism has expanded, I feel the evidence behind the hypothesis that seed oils (corn, soybean, etc.) promote obesity due to their linoleic acid (omega-6 fat) content has largely collapsed.
Read more »
Sunday, 21 August 2011
Seed Oils and Body Fatness-- A Problematic Revisit
Thursday, 18 August 2011
Food Palatability and Body Fatness: Clues from Alliesthesia
Part I: Is there a Ponderostat?
Some of the most important experiments for understanding the role of food palatability/reward in body fatness were performed by Dr. Michel Cabanac and collaborators in the 1970s (hat tip to Dr. Seth Roberts for the references). In my recent food reward series (1), I referenced but did not discuss Dr. Cabanac's work because I felt it would have taken too long to describe. However, I included two of his studies in my Ancestral Health Symposium talk, and I think they're worth discussing in more detail here.
Read more »
Some of the most important experiments for understanding the role of food palatability/reward in body fatness were performed by Dr. Michel Cabanac and collaborators in the 1970s (hat tip to Dr. Seth Roberts for the references). In my recent food reward series (1), I referenced but did not discuss Dr. Cabanac's work because I felt it would have taken too long to describe. However, I included two of his studies in my Ancestral Health Symposium talk, and I think they're worth discussing in more detail here.
Read more »
Monday, 15 August 2011
Book review: Sugar Nation
Jeff O’Connell is the Editor-in-Chief for Bodybuilding.com, a former executive writer for Men’s Health, and former Editor-in-Chief of Muscle & Fitness. He is also the author of a few bestselling books on fitness.
It is obvious that Jeff is someone who can write, and this comes across very clearly in his new book, Sugar Nation.
Now, with a title like this, Sugar Nation, I was expecting a book discussing trends of sugar consumption in the USA, and the related trends in various degenerative diseases. So when I started reading the book I was slightly put off by what seemed to be a book about a very personal journey, written in the first person by the author.
Yet, after reading it for a while I was hooked, and literally could not put the book down. Jeff has managed to write something of a page-turner, combining a harrowing personal account with carefully researched scientific information, about a relatively rare form of type 2 diabetes.
Jeff has a genetic propensity to insulin resistance, just like his father did. What makes Jeff’s case a little unusual is that Jeff is thin, and apparently has difficulty gaining weight. The most common type of diabetes is type 2, and most of those who develop type 2 diabetes do so via the metabolic syndrome. Typically this involves becoming obese or overweight before getting diagnosed as a diabetic.
In fact, in a thin person who is insulin resistant it seems that body fat cells become resistant to the normal actions of insulin much sooner than in the obese. This essentially means that they start rejecting fat. This is a problem, because fat should either be stored in fat cells (adipocytes) or used for energy; as opposed to being deposited in other tissues or remaining in circulation. Apparently this makes it even more difficult for them to control glucose levels once insulin resistance sets in; there is no “cushion”, so to speak.
Still, Jeff appears to believe that his case was that of a skinny-fat person, where body fat percentage is a lot higher than expected based on a low body mass index, and where excess visceral fat is a main culprit. In fact, Jeff seems to think that most cases of thin folks who developed type 2 diabetes are like this, as they follow the metabolic syndrome progression pattern. Fasting triglycerides go up and HDL cholesterol goes down, among other things, but in a skinny-fat body.
Somewhat predictably, what Jeff found out is that, in his case, adopting a low carbohydrate diet made an enormous difference. In fact, it made the difference between having a fairly normal life versus constantly suffering through hypoglycemic episodes. And, at the stage in which Jeff caught the problem, he did not have to avoid all natural carbohydrate-rich foods, not even things like apples. (He had to control portions though.) It is the refined carbohydrate-rich foods that were the problem for him.
I must say that I disagree with a few of the statements in the book. For example, the author seems to believe that excess saturated fat and salt may be quite unhealthy. I think that foods rich in refined carbohydrates and sugars are much more of a problem; cut them out and often excess saturated fat and salt either cease to be a problem, or become healthy. Jeff doesn’t seem to think that excess omega-6 fats can also cause diabetes; I believe the opposite to be true, via a pro-inflammatory path.
Still, this is a great book on so many levels. Jeff meticulously records his experience dealing with doctors, most of whom seem to be clueless as to what to do to prevent the damage that is caused by abnormally high glucose levels. This happens even though diabetes is those doctors’ main area of expertise. He talks about himself with complete abandon, and manages to mix that up with quite a lot of relevant research on diabetes. He gives us an insider’s view of the professional bodybuilding culture, including its use of insulin injections. His description of the Amish is very interesting and somewhat surprising.
For these reasons and a few others, I think this is a great book, and highly recommend it!
(Source: Bodybuilding.com)
It is obvious that Jeff is someone who can write, and this comes across very clearly in his new book, Sugar Nation.
Now, with a title like this, Sugar Nation, I was expecting a book discussing trends of sugar consumption in the USA, and the related trends in various degenerative diseases. So when I started reading the book I was slightly put off by what seemed to be a book about a very personal journey, written in the first person by the author.
Yet, after reading it for a while I was hooked, and literally could not put the book down. Jeff has managed to write something of a page-turner, combining a harrowing personal account with carefully researched scientific information, about a relatively rare form of type 2 diabetes.
Jeff has a genetic propensity to insulin resistance, just like his father did. What makes Jeff’s case a little unusual is that Jeff is thin, and apparently has difficulty gaining weight. The most common type of diabetes is type 2, and most of those who develop type 2 diabetes do so via the metabolic syndrome. Typically this involves becoming obese or overweight before getting diagnosed as a diabetic.
In fact, in a thin person who is insulin resistant it seems that body fat cells become resistant to the normal actions of insulin much sooner than in the obese. This essentially means that they start rejecting fat. This is a problem, because fat should either be stored in fat cells (adipocytes) or used for energy; as opposed to being deposited in other tissues or remaining in circulation. Apparently this makes it even more difficult for them to control glucose levels once insulin resistance sets in; there is no “cushion”, so to speak.
Still, Jeff appears to believe that his case was that of a skinny-fat person, where body fat percentage is a lot higher than expected based on a low body mass index, and where excess visceral fat is a main culprit. In fact, Jeff seems to think that most cases of thin folks who developed type 2 diabetes are like this, as they follow the metabolic syndrome progression pattern. Fasting triglycerides go up and HDL cholesterol goes down, among other things, but in a skinny-fat body.
Somewhat predictably, what Jeff found out is that, in his case, adopting a low carbohydrate diet made an enormous difference. In fact, it made the difference between having a fairly normal life versus constantly suffering through hypoglycemic episodes. And, at the stage in which Jeff caught the problem, he did not have to avoid all natural carbohydrate-rich foods, not even things like apples. (He had to control portions though.) It is the refined carbohydrate-rich foods that were the problem for him.
I must say that I disagree with a few of the statements in the book. For example, the author seems to believe that excess saturated fat and salt may be quite unhealthy. I think that foods rich in refined carbohydrates and sugars are much more of a problem; cut them out and often excess saturated fat and salt either cease to be a problem, or become healthy. Jeff doesn’t seem to think that excess omega-6 fats can also cause diabetes; I believe the opposite to be true, via a pro-inflammatory path.
Still, this is a great book on so many levels. Jeff meticulously records his experience dealing with doctors, most of whom seem to be clueless as to what to do to prevent the damage that is caused by abnormally high glucose levels. This happens even though diabetes is those doctors’ main area of expertise. He talks about himself with complete abandon, and manages to mix that up with quite a lot of relevant research on diabetes. He gives us an insider’s view of the professional bodybuilding culture, including its use of insulin injections. His description of the Amish is very interesting and somewhat surprising.
For these reasons and a few others, I think this is a great book, and highly recommend it!
Thursday, 11 August 2011
The Carbohydrate Hypothesis of Obesity: a Critical Examination
Introduction
I'd like to begin by emphasizing that carbohydrate restriction has helped many people lose body fat and improve their metabolic health. Although it doesn't work for everyone, there is no doubt that carbohydrate restriction causes fat loss in many, perhaps even most obese people. For a subset of people, the results can be very impressive. I consider that to be a fact at this point, but that's not what I'll be discussing here.
What I want to discuss is a hypothesis. It's the idea, championed by Gary Taubes, that carbohydrate (particularly refined carbohydrate) is the primary cause of common obesity due to its ability to elevate insulin, thereby causing increased fat storage in fat cells. To demonstrate that I'm representing this hypothesis accurately, here is a quote from his book Good Calories, Bad Calories:
Read more »
I'd like to begin by emphasizing that carbohydrate restriction has helped many people lose body fat and improve their metabolic health. Although it doesn't work for everyone, there is no doubt that carbohydrate restriction causes fat loss in many, perhaps even most obese people. For a subset of people, the results can be very impressive. I consider that to be a fact at this point, but that's not what I'll be discussing here.
What I want to discuss is a hypothesis. It's the idea, championed by Gary Taubes, that carbohydrate (particularly refined carbohydrate) is the primary cause of common obesity due to its ability to elevate insulin, thereby causing increased fat storage in fat cells. To demonstrate that I'm representing this hypothesis accurately, here is a quote from his book Good Calories, Bad Calories:
Read more »
Monday, 8 August 2011
Ancestral Health Symposium
Last weekend I attended the Ancestral Health Symposium at the University of California, Los Angeles, organized by Aaron Blaisdell, Brent Pottenger and Seth Roberts with help from many others. It was a really great experience and I'm grateful to have been invited. I was finally able to meet many of the people who I respect and admire, but knew only through the internet. I'm not going to make a list because it would be too long, but if you take a look at the symposium schedule, I think you'll understand where I'm coming from. I was also able to connect with a number of Whole Health Source readers, which was great. I recognized some of them from the comments section. Now I know it wasn't just my mom with 57 Google accounts.
The symposium was the first of its kind, and represented many facets of the ancestral health community, including "Paleolithic" diet and exercise patterns, low-carbohydrate diets, Weston Price-style diets, traditional health-nutrition researchers as well as other camps. For the most part they coexisted peacefully and perhaps even learned a thing or two from one another.
I was very impressed by the appearance of the attendees. Young men and women were fit with glowing skin, and older attendees were energetic and aging gracefully. It would be hard to come up with a better advertisement for ancestrally-oriented diets and lifestyles. I saw a lot of people taking the stairs rather than the elevator. I like to say I'll take the elevator/escalator when I'm dead. I think integrating exercise into everyday life is healthy and efficient. Escalators and elevators of course make sense for people with physical disabilities or heavy suitcases.
The first talk was by Dr. Boyd Eaton, considered by many to be the grandfather of the paleolithic diet concept. I was very impressed by his composure, humility and compassionate attitude. Half his talk was dedicated to environmental and social problems. Dr. Staffan Lindeberg gave a talk titled "Food and Western Disease", which covered his paleolithic diet clinical trials as well as other evidence supporting ancestral diets. I like Dr. Lindeberg's humble and skeptical style of reasoning. I had the great pleasure of having dinner with Dr. Lindeberg and his wife, Dr. Eaton, Pedro Bastos, Dr. Lynda Frassetto, Dr. Guy-Andre Pelouze and his son Alexandre. Pedro gave a very nice talk on the complexities of traditional and modern dairy. The following night, I was able to connect with other writers I enjoy, including Chris Masterjohn, Melissa McEwen, John Durant, and Denise Minger.
Dr. Pelouze is a french cardiovascular surgeon who strongly supports the food reward/palatability concept of obesity. We had a conversation the evening before the conference, during which he basically made the same points I was going to make in my talk. He is particularly familiar with the research of Dr. Michel Cabanac, who is central to the food reward idea. He eats an interesting diet: mostly raw, omnivorous, and extremely simple. If I understood correctly, he mostly eats raw meat, fish, fruit and vegetables with little or no preparation. He sometimes cooks food if he wants to, but most of it is raw. He believes simple, raw food allows the body's satiety systems to work more effectively. He has been eating this way for more than twenty years, and his son was raised this way and is now about my age (if I recall correctly, Alexandre has a masters and is studying for an MD, and ultimately wants to become an MD/PhD). Both of them look very good, are full of energy and have a remarkably positive mental state. Alexandre told me that he never felt deprived growing up around other children who ate pastries, candy et cetera. They woke up early and ran six miles before the conference began at 8 am.
I gave my talk on Friday. Giving a talk is not like writing a blog post-- it has to be much more cohesive and visually compelling. I put a lot of work into it and it went really well. Besides the heat I got from from Gary Taubes in the question and answer session, the response was very positive. The talk, including the questions, will be freely available on the internet soon, as well as other talks from the symposium. Some of it will be familiar to people who have read my body fat setpoint and food reward series, but it's a concise summary of the ideas and parts of it are new, so it will definitely be worthwhile to watch it.
We have entered a new era of media communication. Every time someone sneezed, it was live tweeted. There are some good aspects to it-- it democratizes information by making it more accessible. On the other hand, it's sometimes low quality information that contains inaccurate accounts and quotes that are subsequently recirculated.
It was a great conference and I hope it was the first of many.
The symposium was the first of its kind, and represented many facets of the ancestral health community, including "Paleolithic" diet and exercise patterns, low-carbohydrate diets, Weston Price-style diets, traditional health-nutrition researchers as well as other camps. For the most part they coexisted peacefully and perhaps even learned a thing or two from one another.
I was very impressed by the appearance of the attendees. Young men and women were fit with glowing skin, and older attendees were energetic and aging gracefully. It would be hard to come up with a better advertisement for ancestrally-oriented diets and lifestyles. I saw a lot of people taking the stairs rather than the elevator. I like to say I'll take the elevator/escalator when I'm dead. I think integrating exercise into everyday life is healthy and efficient. Escalators and elevators of course make sense for people with physical disabilities or heavy suitcases.
The first talk was by Dr. Boyd Eaton, considered by many to be the grandfather of the paleolithic diet concept. I was very impressed by his composure, humility and compassionate attitude. Half his talk was dedicated to environmental and social problems. Dr. Staffan Lindeberg gave a talk titled "Food and Western Disease", which covered his paleolithic diet clinical trials as well as other evidence supporting ancestral diets. I like Dr. Lindeberg's humble and skeptical style of reasoning. I had the great pleasure of having dinner with Dr. Lindeberg and his wife, Dr. Eaton, Pedro Bastos, Dr. Lynda Frassetto, Dr. Guy-Andre Pelouze and his son Alexandre. Pedro gave a very nice talk on the complexities of traditional and modern dairy. The following night, I was able to connect with other writers I enjoy, including Chris Masterjohn, Melissa McEwen, John Durant, and Denise Minger.
Dr. Pelouze is a french cardiovascular surgeon who strongly supports the food reward/palatability concept of obesity. We had a conversation the evening before the conference, during which he basically made the same points I was going to make in my talk. He is particularly familiar with the research of Dr. Michel Cabanac, who is central to the food reward idea. He eats an interesting diet: mostly raw, omnivorous, and extremely simple. If I understood correctly, he mostly eats raw meat, fish, fruit and vegetables with little or no preparation. He sometimes cooks food if he wants to, but most of it is raw. He believes simple, raw food allows the body's satiety systems to work more effectively. He has been eating this way for more than twenty years, and his son was raised this way and is now about my age (if I recall correctly, Alexandre has a masters and is studying for an MD, and ultimately wants to become an MD/PhD). Both of them look very good, are full of energy and have a remarkably positive mental state. Alexandre told me that he never felt deprived growing up around other children who ate pastries, candy et cetera. They woke up early and ran six miles before the conference began at 8 am.
I gave my talk on Friday. Giving a talk is not like writing a blog post-- it has to be much more cohesive and visually compelling. I put a lot of work into it and it went really well. Besides the heat I got from from Gary Taubes in the question and answer session, the response was very positive. The talk, including the questions, will be freely available on the internet soon, as well as other talks from the symposium. Some of it will be familiar to people who have read my body fat setpoint and food reward series, but it's a concise summary of the ideas and parts of it are new, so it will definitely be worthwhile to watch it.
We have entered a new era of media communication. Every time someone sneezed, it was live tweeted. There are some good aspects to it-- it democratizes information by making it more accessible. On the other hand, it's sometimes low quality information that contains inaccurate accounts and quotes that are subsequently recirculated.
It was a great conference and I hope it was the first of many.
Potassium deficiency in low carbohydrate dieting: High protein and fat alternatives that do not involve supplementation
It is often pointed out, at least anecdotally, that potassium deficiency is common among low carbohydrate dieters. Potassium deficiency can lead to a number of unpleasant symptoms and health problems. This micronutrient is present in small quantities in meat and seafood; main sources are plant foods.
A while ago this has gotten me thinking and asking myself: what about isolated hunter-gatherers that seem to have thrived consuming mostly carnivorous diets with little potassium, such as various Native American tribes?
Another thought came to mind, which is that animal protein seems to be associated with increased bone mineralization, even when calcium intake is low. That seems to be due to animal protein being associated with increased absorption of calcium and other minerals that make up bone tissue.
Maybe animal protein intake is also associated with increased potassium absorption. If this is true, what could be the possible mechanism?
As it turns out, there is one possible and somewhat surprising connection, insulin seems to promote cell uptake of potassium. This is an argument made many years ago by Clausen and Kohn, and further discussed more recently by Benziane and Chibalin. See also this recent commentary by Clausen.
Protein is the only macronutrient that normally causes transient insulin elevation without any glucose response. And the insulin response to protein is nowhere near that associated with refined carbohydrate-rich foods. It is much lower, analogous to the response to natural carbohydrate-rich foods.
A very low carbohydrate diet with more animal protein, and less fat, would induce insulin responses after meals, possibly helping with the absorption of potassium, even if potassium intake were rather limited. Primarily carnivorous diets, like those of some traditional Native American groups, would fit the bill.
Also, a low carbohydrate diet with emphasis on fat, but that was not so low in carbohydrates from certain sources, would probably achieve the same effect. This latter sounds like Kwaśniewski’s Optimal Diet, where people are encouraged to eat a lot more fat than protein, but also a small amount of carbohydrates (e.g., 50-100 g/d) from things like potatoes.
Kwaśniewski’s suggestions may sound counterintuitive sometimes. But, as it turns out, potatoes are good sources of potassium. One potato may not be a lot, but that potato will also increase insulin levels, bringing potassium intake up at the cell level.
A while ago this has gotten me thinking and asking myself: what about isolated hunter-gatherers that seem to have thrived consuming mostly carnivorous diets with little potassium, such as various Native American tribes?
Another thought came to mind, which is that animal protein seems to be associated with increased bone mineralization, even when calcium intake is low. That seems to be due to animal protein being associated with increased absorption of calcium and other minerals that make up bone tissue.
Maybe animal protein intake is also associated with increased potassium absorption. If this is true, what could be the possible mechanism?
As it turns out, there is one possible and somewhat surprising connection, insulin seems to promote cell uptake of potassium. This is an argument made many years ago by Clausen and Kohn, and further discussed more recently by Benziane and Chibalin. See also this recent commentary by Clausen.
Protein is the only macronutrient that normally causes transient insulin elevation without any glucose response. And the insulin response to protein is nowhere near that associated with refined carbohydrate-rich foods. It is much lower, analogous to the response to natural carbohydrate-rich foods.
A very low carbohydrate diet with more animal protein, and less fat, would induce insulin responses after meals, possibly helping with the absorption of potassium, even if potassium intake were rather limited. Primarily carnivorous diets, like those of some traditional Native American groups, would fit the bill.
Also, a low carbohydrate diet with emphasis on fat, but that was not so low in carbohydrates from certain sources, would probably achieve the same effect. This latter sounds like Kwaśniewski’s Optimal Diet, where people are encouraged to eat a lot more fat than protein, but also a small amount of carbohydrates (e.g., 50-100 g/d) from things like potatoes.
Kwaśniewski’s suggestions may sound counterintuitive sometimes. But, as it turns out, potatoes are good sources of potassium. One potato may not be a lot, but that potato will also increase insulin levels, bringing potassium intake up at the cell level.
Monday, 1 August 2011
There is no doubt that abnormally elevated insulin is associated with body fat accumulation
For as long as diets existed there have been influential proponents, or believers, who at some point had what they thought were epiphanies. From that point forward, they disavowed the diets that they formally endorsed. Low carbohydrate dieting seems to be in this situation now. Among other things, it has been recently “discovered” that the idea that insulin drives fat into body fat cells is “wrong”.
Based on some of the comments I have been receiving lately, apparently a few readers think that I am one of those “enlightened”. If you are interested in what I have been eating, for quite some time now, just click on the link at the top of this blog that refers to my transformation. It is essentially high in all macronutrients on days that I exercise, and low in carbohydrates and calories on days that I don’t. It is a cyclic approach that works for me; calorie surpluses on some days and calorie deficits on other days.
But let me set the record straight regarding what I think: there is no doubt that insulin is associated with body fat accumulation. I was told that an influential health blogger (whom I respect a lot) denied this recently, going to the extreme of saying that no professional metabolism or endocrinology researcher believes in it, but I couldn’t find any evidence of that statement. It is not hard at all to find professional metabolism and endocrinology researchers who have asserted that insulin is associated with body fat accumulation, based on very reliable evidence. Actually, this is Biochemistry 101.
What I think is truly unclear is whether insulin spikes associated with carbohydrate-rich foods in general are the cause of obesity. This idea is, indeed, probably wrong given the evidence we have from various human populations whose members consume plenty of non-industrialized carbohydrate-rich foods. On a related note, I particularly disagree with the notion that the pancreas gets tired over time due to having to secrete insulin in bursts, which seems to also be one of the foundations on which many low carbohydrate diet varieties rest.
As with almost everything related to health, the role of insulin in body fat gain is complex, and part of that complexity is due to the nonlinear relationship between body fat gain and postprandial insulin release. Industrial carbohydrate-rich foods have a much higher glycemic load than natural carbohydrate-rich foods, even though their glycemic index may be the same in some cases. In other words, the quantity of easily digestible carbohydrates per gram is much higher in industrial carbohydrate-rich foods.
In normoglycemic folks, this leads to an abnormally elevated insulin response, among other hormonal responses. For example, circulating growth hormone, which promotes body fat loss, is inversely correlated with circulating insulin. Insulin drives fat, typically from dietary sources of fat, into adipocytes. That fat may also come from excess carbohydrates, packaged into VLDL particles.
Under normal circumstances, that would be fine, since our body is designed to store fat and release it as needed. But the abnormal insulin response elicited by industrial carbohydrate-rich foods, together with other hormonal responses, leads to a little more body fat accumulation, and for longer, than it should. And I’m talking here about people without any metabolic damage. Saturated and monounsaturated fats are healthy when eaten, but when they are stored as excess body fat, they become pro-inflammatory.
Body fat is like an organ, secreting many hormones into the bloodstream, several of which are pro-inflammatory. One of those pro-inflammatory hormones, which I believe is closely linked with many diseases of civilization, is tumor necrosis factor. (The acronym is now TNF. Apparently the “-alpha” after its name and acronym has been dropped recently.) Dietary fat, particularly saturated fat, seems to be anti-inflammatory. In other words, body fat accumulation is the problem. You only need 30 g/d of excess body fat accumulation to gain around 24 lbs of fat per year. Over three years, that will add up to over 70 lbs of body fat.
In my view, ultimately it is excess inflammation (which is, in essence, a vascular response) that is at the source of most of the diseases of civilization.
That is where the nonlinearity comes in. Insulin is healthy up to a point. Beyond that, it starts causing health problems, over time. And one of the main mechanisms by which it does so is via excessive body fat accumulation, with different damage threshold levels for different people. Insulin may decrease appetite as it goes up, but it increases it if goes down too much. If it goes up abnormally, typically it will go down too much. As it reaches a trough it induces hypoglycemia, even if mildly.
Take a look at the graph below, from this post showing the glucose variations in normoglycemic individuals. There is a lot of variation among different individuals, but it is clear that the magnitude of the hypoglycemic dips is inversely correlated with the magnitude of the glucose spikes. That inverse correlation is due primarily to the effect of insulin. Under normal circumstances, a decrease in circulating insulin would promote an increase in free fatty acids in circulation, which would normally have a suppressing effect on hunger in the hours after a meal. But industrial carbohydrate-rich foods lead to increases and decreases in glucose and insulin that are too steep, causing the opposite effect.
You may ask: why do you keep talking about industrial carbohydrate-rich foods? Why not talk about industrial protein- or fat-rich foods as well? The reason is that the food industry has not been very successful at producing industrial protein- or fat-rich foods that are palatable without adding a lot of carbohydrate to them.
More often than not they need enough carbohydrate added in the form of sugar to become truly addictive.
Based on some of the comments I have been receiving lately, apparently a few readers think that I am one of those “enlightened”. If you are interested in what I have been eating, for quite some time now, just click on the link at the top of this blog that refers to my transformation. It is essentially high in all macronutrients on days that I exercise, and low in carbohydrates and calories on days that I don’t. It is a cyclic approach that works for me; calorie surpluses on some days and calorie deficits on other days.
But let me set the record straight regarding what I think: there is no doubt that insulin is associated with body fat accumulation. I was told that an influential health blogger (whom I respect a lot) denied this recently, going to the extreme of saying that no professional metabolism or endocrinology researcher believes in it, but I couldn’t find any evidence of that statement. It is not hard at all to find professional metabolism and endocrinology researchers who have asserted that insulin is associated with body fat accumulation, based on very reliable evidence. Actually, this is Biochemistry 101.
What I think is truly unclear is whether insulin spikes associated with carbohydrate-rich foods in general are the cause of obesity. This idea is, indeed, probably wrong given the evidence we have from various human populations whose members consume plenty of non-industrialized carbohydrate-rich foods. On a related note, I particularly disagree with the notion that the pancreas gets tired over time due to having to secrete insulin in bursts, which seems to also be one of the foundations on which many low carbohydrate diet varieties rest.
As with almost everything related to health, the role of insulin in body fat gain is complex, and part of that complexity is due to the nonlinear relationship between body fat gain and postprandial insulin release. Industrial carbohydrate-rich foods have a much higher glycemic load than natural carbohydrate-rich foods, even though their glycemic index may be the same in some cases. In other words, the quantity of easily digestible carbohydrates per gram is much higher in industrial carbohydrate-rich foods.
In normoglycemic folks, this leads to an abnormally elevated insulin response, among other hormonal responses. For example, circulating growth hormone, which promotes body fat loss, is inversely correlated with circulating insulin. Insulin drives fat, typically from dietary sources of fat, into adipocytes. That fat may also come from excess carbohydrates, packaged into VLDL particles.
Under normal circumstances, that would be fine, since our body is designed to store fat and release it as needed. But the abnormal insulin response elicited by industrial carbohydrate-rich foods, together with other hormonal responses, leads to a little more body fat accumulation, and for longer, than it should. And I’m talking here about people without any metabolic damage. Saturated and monounsaturated fats are healthy when eaten, but when they are stored as excess body fat, they become pro-inflammatory.
Body fat is like an organ, secreting many hormones into the bloodstream, several of which are pro-inflammatory. One of those pro-inflammatory hormones, which I believe is closely linked with many diseases of civilization, is tumor necrosis factor. (The acronym is now TNF. Apparently the “-alpha” after its name and acronym has been dropped recently.) Dietary fat, particularly saturated fat, seems to be anti-inflammatory. In other words, body fat accumulation is the problem. You only need 30 g/d of excess body fat accumulation to gain around 24 lbs of fat per year. Over three years, that will add up to over 70 lbs of body fat.
In my view, ultimately it is excess inflammation (which is, in essence, a vascular response) that is at the source of most of the diseases of civilization.
That is where the nonlinearity comes in. Insulin is healthy up to a point. Beyond that, it starts causing health problems, over time. And one of the main mechanisms by which it does so is via excessive body fat accumulation, with different damage threshold levels for different people. Insulin may decrease appetite as it goes up, but it increases it if goes down too much. If it goes up abnormally, typically it will go down too much. As it reaches a trough it induces hypoglycemia, even if mildly.
Take a look at the graph below, from this post showing the glucose variations in normoglycemic individuals. There is a lot of variation among different individuals, but it is clear that the magnitude of the hypoglycemic dips is inversely correlated with the magnitude of the glucose spikes. That inverse correlation is due primarily to the effect of insulin. Under normal circumstances, a decrease in circulating insulin would promote an increase in free fatty acids in circulation, which would normally have a suppressing effect on hunger in the hours after a meal. But industrial carbohydrate-rich foods lead to increases and decreases in glucose and insulin that are too steep, causing the opposite effect.
You may ask: why do you keep talking about industrial carbohydrate-rich foods? Why not talk about industrial protein- or fat-rich foods as well? The reason is that the food industry has not been very successful at producing industrial protein- or fat-rich foods that are palatable without adding a lot of carbohydrate to them.
More often than not they need enough carbohydrate added in the form of sugar to become truly addictive.
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