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Not too much to go on here without the paywall-locked pdf. That said, from the abstract it seems their model of obesity depends on fructose-caused hunger drivin

by dilap 3y ago

Not too much to go on here without the paywall-locked pdf. That said, from the abstract it seems their model of obesity depends on fructose-caused hunger driving consumption of fat: "metabolic effects that result in the increased intake of energy-dense fats." Whatever that means. It is true, I think, that most of our body fat comes from our diet, so at some level any theory of obesity ultimately has to come down to consuming fat. (Which also implies if you stick to a low-fat diet, you will not be obese. Though you might be miserable or unhealthy.) At a population level, has fructose consumption been going up as obesity has increased? That could serve as a sanity-check of the theory. (I don't know the answer to the question, so it's a real question.)

tracerbulletx 3y ago
This is the exact opposite of what I understood to be the case. I thought that if you eat more calories than you consume you store them as fat, it doesn't matter if what you consume is fat or not, in fact consuming fat can help because it takes longer to digest and keeps you full and you may eat less than if you are eating sugary things that digest quickly.
- mnw21cam 3y ago
  You're partially right. It's a complete fallacy to think that just because you consume fat, you store fat. Any fat you eat is broken down before going into the bloodstream, and is generally made available for the body to use as fuel in preference to being stored. The reason you store fat is because you have insulin in your bloodstream, which is a messenger telling cells to store energy. Insulin is released into the bloodstream in response to blood sugar levels going up. So, in order to avoid storing fat, you should avoid eating sugar (and other foods that get converted into sugar quickly, like most carbohydrates). People tend to lose weight if they consume mostly fat, and that is largely because eating fat doesn't raise blood sugar levels, and therefore doesn't stimulate insulin secretion. So it's more complicated than calories in minus calories out, and fat is good for more complicated reasons than it just taking longer to digest. Fructose does have a bad effect. But that's separate from the above - fructose is even more bad than just it being a sugar.
pif 3y ago
> It is true, I think, that most of our body fat comes from our diet I am pretty sure your assumption is wrong. Stored fat has no correlation with the composition of your diet, but only with the amount of excess calories.
- dilap 3y ago
  I don't think this is right -- my understanding is the fat tissue closely correlates with fat in the diet. E.g., "Tissue and blood fatty acids, because they are mainly derived from the diet, have been used as biomarkers of dietary intake for a number of years." from "Fatty acid composition of adipose tissue and blood in humans and its use as a biomarker of dietary intake" https://www.sciencedirect.com/science/article/abs/pii/S0163782708000283?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S01637... Of course, lipogenesis is a thing, but it only produces SFA or MFA -- not PUFA. I can't find a reference, but if I'm not mistaken obese people have a higher percentage of body fat as PUFA than non-obese people, which, if true, is another way we can tell a significant portion of their fat must be coming from the diet. I guess it might be possible to eat sufficient quantities of high-carb, very-low-fat diet to drive enough lipogenesis to get fat, though I don't know if this actually happens in practice. As one sort of silly example, people eating a pure potato diet lose weight easily, with no restriction on total calories.
stetrain 3y ago
> has to come down to consuming fat. Consuming fat is not the only part of your diet that can result in body fat. https://en.wikipedia.org/wiki/Lipogenesis https://en.wikipedia.org/wiki/Lipogenesis
lamontcg 3y ago
> Not too much to go on here without the paywall-locked pdf https://royalsocietypublishing.org/doi/10.1098/rstb.2022.0230 https://royalsocietypublishing.org/doi/10.1098/rstb.2022.023... that works for me.
deleted 3y ago
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by dilap 3y ago

tracerbulletx 3y ago

This is the exact opposite of what I understood to be the case. I thought that if you eat more calories than you consume you store them as fat, it doesn't matter if what you consume is fat or not, in fact consuming fat can help because it takes longer to digest and keeps you full and you may eat less than if you are eating sugary things that digest quickly.

mnw21cam 3y ago
You're partially right. It's a complete fallacy to think that just because you consume fat, you store fat. Any fat you eat is broken down before going into the bloodstream, and is generally made available for the body to use as fuel in preference to being stored. The reason you store fat is because you have insulin in your bloodstream, which is a messenger telling cells to store energy. Insulin is released into the bloodstream in response to blood sugar levels going up. So, in order to avoid storing fat, you should avoid eating sugar (and other foods that get converted into sugar quickly, like most carbohydrates). People tend to lose weight if they consume mostly fat, and that is largely because eating fat doesn't raise blood sugar levels, and therefore doesn't stimulate insulin secretion. So it's more complicated than calories in minus calories out, and fat is good for more complicated reasons than it just taking longer to digest. Fructose does have a bad effect. But that's separate from the above - fructose is even more bad than just it being a sugar.

pif 3y ago

> It is true, I think, that most of our body fat comes from our diet I am pretty sure your assumption is wrong. Stored fat has no correlation with the composition of your diet, but only with the amount of excess calories.

dilap 3y ago
I don't think this is right -- my understanding is the fat tissue closely correlates with fat in the diet. E.g., "Tissue and blood fatty acids, because they are mainly derived from the diet, have been used as biomarkers of dietary intake for a number of years." from "Fatty acid composition of adipose tissue and blood in humans and its use as a biomarker of dietary intake" https://www.sciencedirect.com/science/article/abs/pii/S0163782708000283?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S01637... Of course, lipogenesis is a thing, but it only produces SFA or MFA -- not PUFA. I can't find a reference, but if I'm not mistaken obese people have a higher percentage of body fat as PUFA than non-obese people, which, if true, is another way we can tell a significant portion of their fat must be coming from the diet. I guess it might be possible to eat sufficient quantities of high-carb, very-low-fat diet to drive enough lipogenesis to get fat, though I don't know if this actually happens in practice. As one sort of silly example, people eating a pure potato diet lose weight easily, with no restriction on total calories.

stetrain 3y ago

> has to come down to consuming fat. Consuming fat is not the only part of your diet that can result in body fat. https://en.wikipedia.org/wiki/Lipogenesis https://en.wikipedia.org/wiki/Lipogenesis

lamontcg 3y ago

> Not too much to go on here without the paywall-locked pdf https://royalsocietypublishing.org/doi/10.1098/rstb.2022.0230 https://royalsocietypublishing.org/doi/10.1098/rstb.2022.023... that works for me.

deleted 3y ago

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