So why does this positive feedback cycle start in some people, but not others?
This is his description:
You think about eating a meal containing carbohydrates.
You begin secreting insulin.
The insulin signals the fat cells to shut down the release of fatty acids (by inhibiting HSL) and take up more fatty acids (via LPL) from the circulation.
You start to get hungry, or hungrier.
You begin eating.
You secrete more insulin.
The carbohydrates are digested and enter the circulation as glucose, causing blood sugar levels to rise.
You secrete still more insulin.
Fat from the diet is stored as triglycerides in the fat cells, as are some of the carbohydrates that are converted into fat in the liver.
The fat cells get fatter, and so do you.
The fat stays in the fat cells until the insulin level drops.
But it gets worse because over time your cells start being resistant to insulin, so in order to overcome that, you emit even more insulin, and so you get even fatter. According to him this is why people tend to get heavier as they age. And if a time comes when you can’t emit enough insulin to overcome the resistance, then you get diabetes.
Two arguments he tries to make from common sense:
No one expects a boy or girl to have their growth stunted from too much exercise. Instead, they will feel hungrier and eat more. In the same way when the insulin makes you get fatter, you will not stunt the fat growth by exercising. Instead, you will feel hungrier and eat more.
Both eating less and exercising more make you hungrier, which makes you eat more, which makes you heavier. So the methods that people tell you to use to lose weight, cannot work. And this corresponds with how fasting diets normally work in the real world: people lose some weight, but they feel hungry all the time, so they stop, and they get the weight back.
His theoretical explanation is that carbohydrates are relatively new to humanity’s diet, at least in significant quantities. So people are not as well adapted to them as to fat and protein. If you are gaining 2lbs of weight per year, that is still a very precise match of calories in to calories out, just not as precise as keeping your weight absolutely even.
But that is where the difference between people will turn out to be. Some people are lactose intolerant for similar reasons, but not everyone is. This is on account of genetic differences. In the same way some people can maintain their weight while eating carbohydrates, but most people cannot, and this would be on account of similar genetic differences. So his overall argument is that if you want to lose weight, you should eat less carbohydrates and more fat and protein. According to him, any degree of this will make you lose weight (or not gain it as fast), and make you healthier (or not get sicker as fast), and doing it more will just have more of those effects, all the way up to having no carbohydrates at all.
That’s pretty clearly not true.
Here is his description of the rat experiment:
In the early 1970s, a young researcher at the University of Massachusetts named George Wade set out to study the relationship between sex hormones, weight, and appetite by removing the ovaries from rats (females, obviously) and then monitoring their subsequent weight and behavior.* The effects of the surgery were suitably dramatic: the rats would begin to eat voraciously and quickly become obese. If we didn’t know any better, we might assume from this that the removal of a rat’s ovaries makes it a glutton. The rat eats too much, the excess calories find their way to the fat tissue, and the animal becomes obese. This would confirm our preconception that overeating is responsible for obesity in humans as well. But Wade did a revealing second experiment, removing the ovaries from the rats and putting them on a strict postsurgical diet. Even if these rats were ravenously hungry after the surgery, even if they desperately wanted to be gluttons, they couldn’t satisfy their urge. In the lingo of experimental science, this second experiment controlled for overeating. The rats, postsurgery, were only allowed the same amount of food they would have eaten had they never had the surgery. What happened is not what you’d probably think. The rats got just as fat, just as quickly. But these rats were now completely sedentary. They moved only when movement was required to get food.
You are thinking of a situation where they are not allowed to eat at all. Of course nothing will get fat in that situation. However, here is another passage:
Let’s think about this for a second. If a baby rat that is genetically programmed to become obese is put on a diet from the moment it’s weaned, so it can eat no more than a lean rat would eat, if that, and can never eat as much as it would like, it responds by compromising its organs and muscles to satisfy its genetic drive to grow fat. It’s not just using the energy it would normally expend in day-to-day activity to grow fat; it’s taking the materials and the energy it would normally dedicate to building its muscles, organs, and even its brain and using that. When these obese rodents are starved to death—an experiment that fortunately not too many researchers have done—a common result reported in the literature is that the animals die with much of their fat tissue intact. In fact, they’ll often die with more body fat than lean animals have when the lean ones are eating as much as they like. As animals starve, and the same is true of humans, they consume their muscles for fuel, and that includes, eventually, the heart muscle. As adults, these obese animals are willing to compromise their organs, even their hearts and their lives, to preserve their fat.
In other words, it is not a question of getting fat without eating. The point is that the body has decided to put on fat, so that is the first thing that is done with the incoming calories. If you do not want to starve, you will have to eat more.
Think of the crowd example. OP suggests “they are overeating because they are getting fat” doesn’t make sense for the crowd. But it does: “more people are coming into the room than leaving, because many of the ones coming in are insisting on staying in and not going out.”
The idea that insulin drives obesity was popular for a while (did Gary Taubes start it?) but I thought it didn’t fare too well when tested against reality (see e.g. this and this)
Two arguments he tries to make from common sense
That’s not common sense, that’s analogies which might be useful rhetorically but which don’t do anything to show that his view is correct.
carbohydrates are relatively new to humanity’s diet, at least in significant quantities
I don’t know about that. Carbs are a significant part of the human diet since the farming revolution which happened sufficiently long time ago for the body to somewhat adapt (e.g. see the lactose tolerance mutation which is more recent).
Besides, let’s consider what was the situation, say, 200 years ago. Were carbs a major part of diet? Sure they were. Was there an “obesity epidemic”? Nope, not at all.
If you want to blame carbs (not even refined carbs like sugar, but carbs in general) for obesity, you need to have an explanation why their evil magic didn’t work before the XX century.
You are thinking of a situation where they are not allowed to eat at all.
No, I’m not. For any animal, humans included, there is non-zero intake of food which will force it to lose weight.
If you do not want to starve, you will have to eat more.
“Starve” seems to mean exactly the same thing as “lose weight by calorie restriction”, but with negative connotations.
And I don’t know about modified rats, but starving humans are not fat. Feel free to peruse pictures of starving people.
but I thought it didn’t fare too well when tested against reality (see e.g. this and this)
I can’t comment on those in detail without reading them more carefully than I care to, but that author agrees with Taubes that low carb diets help most people lose weight, and he seems to be assuming a particular model (e.g. he contrasts the brain being responsible with insulin being responsible, while it is obvious that these are not necessarily opposed.)
That’s not common sense, that’s analogies which might be useful rhetorically but which don’t do anything to show that his view is correct.
They don’t show that his view is correct. They DO show that it is not absurd.
Carbs are a significant part of the human diet since the farming revolution which happened sufficiently long time ago for the body to somewhat adapt (e.g. see the lactose tolerance mutation which is more recent).
Lactose intolerance is also more harmful to people. Gaining weight usually just means you lose a few years of life. Taubes also admits that some people are well adapted to them. Those would be the people that normal people would describe by saying “they can eat as much as they like without getting fat.”
If you want to blame carbs (not even refined carbs like sugar, but carbs in general) for obesity, you need to have an explanation why their evil magic didn’t work before the XX century.
He blames carbs in general, but he also says that sweeter or more easily digestible ones are worse, so he is blaming refined carbs more, and saying the effects are worse.
No, I’m not. For any animal, humans included, there is non-zero intake of food which will force it to lose weight.
Sure, but they might be getting fat at the same time. They could be gaining fat and losing even more of other tissue, and this is what Taubes says happened with some of the rats.
“Starve” seems to mean exactly the same thing as “lose weight by calorie restriction”, but with negative connotations.
No. I meant that your body is being damaged by calorie restriction, not just losing weight.
And I don’t know about modified rats, but starving humans are not fat.
He gives some partial counterexamples to this in the book.
This is his description:
You think about eating a meal containing carbohydrates.
You begin secreting insulin.
The insulin signals the fat cells to shut down the release of fatty acids (by inhibiting HSL) and take up more fatty acids (via LPL) from the circulation.
You start to get hungry, or hungrier.
You begin eating.
You secrete more insulin.
The carbohydrates are digested and enter the circulation as glucose, causing blood sugar levels to rise.
You secrete still more insulin.
Fat from the diet is stored as triglycerides in the fat cells, as are some of the carbohydrates that are converted into fat in the liver.
The fat cells get fatter, and so do you.
The fat stays in the fat cells until the insulin level drops.
But it gets worse because over time your cells start being resistant to insulin, so in order to overcome that, you emit even more insulin, and so you get even fatter. According to him this is why people tend to get heavier as they age. And if a time comes when you can’t emit enough insulin to overcome the resistance, then you get diabetes.
Two arguments he tries to make from common sense:
No one expects a boy or girl to have their growth stunted from too much exercise. Instead, they will feel hungrier and eat more. In the same way when the insulin makes you get fatter, you will not stunt the fat growth by exercising. Instead, you will feel hungrier and eat more.
Both eating less and exercising more make you hungrier, which makes you eat more, which makes you heavier. So the methods that people tell you to use to lose weight, cannot work. And this corresponds with how fasting diets normally work in the real world: people lose some weight, but they feel hungry all the time, so they stop, and they get the weight back.
His theoretical explanation is that carbohydrates are relatively new to humanity’s diet, at least in significant quantities. So people are not as well adapted to them as to fat and protein. If you are gaining 2lbs of weight per year, that is still a very precise match of calories in to calories out, just not as precise as keeping your weight absolutely even.
But that is where the difference between people will turn out to be. Some people are lactose intolerant for similar reasons, but not everyone is. This is on account of genetic differences. In the same way some people can maintain their weight while eating carbohydrates, but most people cannot, and this would be on account of similar genetic differences. So his overall argument is that if you want to lose weight, you should eat less carbohydrates and more fat and protein. According to him, any degree of this will make you lose weight (or not gain it as fast), and make you healthier (or not get sicker as fast), and doing it more will just have more of those effects, all the way up to having no carbohydrates at all.
Here is his description of the rat experiment:
You are thinking of a situation where they are not allowed to eat at all. Of course nothing will get fat in that situation. However, here is another passage:
In other words, it is not a question of getting fat without eating. The point is that the body has decided to put on fat, so that is the first thing that is done with the incoming calories. If you do not want to starve, you will have to eat more.
Think of the crowd example. OP suggests “they are overeating because they are getting fat” doesn’t make sense for the crowd. But it does: “more people are coming into the room than leaving, because many of the ones coming in are insisting on staying in and not going out.”
The idea that insulin drives obesity was popular for a while (did Gary Taubes start it?) but I thought it didn’t fare too well when tested against reality (see e.g. this and this)
That’s not common sense, that’s analogies which might be useful rhetorically but which don’t do anything to show that his view is correct.
I don’t know about that. Carbs are a significant part of the human diet since the farming revolution which happened sufficiently long time ago for the body to somewhat adapt (e.g. see the lactose tolerance mutation which is more recent).
Besides, let’s consider what was the situation, say, 200 years ago. Were carbs a major part of diet? Sure they were. Was there an “obesity epidemic”? Nope, not at all.
If you want to blame carbs (not even refined carbs like sugar, but carbs in general) for obesity, you need to have an explanation why their evil magic didn’t work before the XX century.
No, I’m not. For any animal, humans included, there is non-zero intake of food which will force it to lose weight.
“Starve” seems to mean exactly the same thing as “lose weight by calorie restriction”, but with negative connotations.
And I don’t know about modified rats, but starving humans are not fat. Feel free to peruse pictures of starving people.
I can’t comment on those in detail without reading them more carefully than I care to, but that author agrees with Taubes that low carb diets help most people lose weight, and he seems to be assuming a particular model (e.g. he contrasts the brain being responsible with insulin being responsible, while it is obvious that these are not necessarily opposed.)
They don’t show that his view is correct. They DO show that it is not absurd.
Lactose intolerance is also more harmful to people. Gaining weight usually just means you lose a few years of life. Taubes also admits that some people are well adapted to them. Those would be the people that normal people would describe by saying “they can eat as much as they like without getting fat.”
He blames carbs in general, but he also says that sweeter or more easily digestible ones are worse, so he is blaming refined carbs more, and saying the effects are worse.
Sure, but they might be getting fat at the same time. They could be gaining fat and losing even more of other tissue, and this is what Taubes says happened with some of the rats.
No. I meant that your body is being damaged by calorie restriction, not just losing weight.
He gives some partial counterexamples to this in the book.
Please fix the formatting. Edit: thanks