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There are two things that come to mind when we ask if dietary fat causes obesity. First: fat and carbohydrates sum to literally all of food. The caloric value o

by scythe 14y ago

There are two things that come to mind when we ask if dietary fat causes obesity. First: fat and carbohydrates sum to literally all of food. The caloric value of protein is (essentially) negligible. What is certainly the case is that we can point to people who are fat (preferred term) on a low-fat diet. We can point to people who are fat on a fat-intermediate diet (rough balance of fat/carbs). Can we find many people who are fat on a low-carb diet? I suggest that if we do, most such people will not be found eating fat in its natural form, but as rendered fat and pressed oil. It is almost certainly the case that the way in which fat is consumed affects satiety: the body cannot see a caloric benefit from fat until it is beta-oxidized in the liver, many hours after it is consumed. So in order to estimate how much you have eaten, the body assumes you have consumed fats in their natural form. This is key to most low-carb diets: fat is usually consumed in its natural form, since nobody drinks oil (eww) and fatty snacks such as potato chips are banned. It is also an intrinsic feature of the "paleo" diets, which ban processed foods. So, it might not be too much of a stretch to say that fat as a naturally occuring part of foods like almonds does not make us fat. The second thing that comes to mind is the balance of omega-6 and omega-3 fatty acids in a healthy diet. When this is tilted excessively in favor of omega-6, the body produces an excess of certain endocannabinoids (arachidonic acid) which contribute to overeating: http://www.sciencedaily.com/releases/2010/07/100726221737.htm http://www.sciencedaily.com/releases/2010/07/100726221737.ht... [NB: the mechanism is up in the air. The effect is real.] The additional, final consideration is the alleged link (as stated in the article) between consumption of land meats and obesity. See https://en.wikipedia.org/wiki/Red_meat#Obesity https://en.wikipedia.org/wiki/Red_meat#Obesity I've been harping on "natural", and meat is natural, so what gives? Weirder yet, the correlation is with meat protein, not with fats. And we do know, though, that people on e.g. ketogenic diets lose weight while eating lots of meat: http://ajcn.nutrition.org/content/82/1/1.short http://ajcn.nutrition.org/content/82/1/1.short The simplest way to assign blame is to cry confounding: while meat itself is natural, it is rarely consumed in a natural-food context. Instead, since meat is culturally considered unhealthy, it is often eaten on white bread or in a pack of Lunchables. Support for the confounding hypothesis would be a low r-value in studies that link meat consumption to body fat (i.e. total variation in body fat is only weakly related to variation in meat consumption); falsification might be a very high r-value, or a very well-controlled study. [NB: I believe the confounding hypothesis.]

BlackJack 14y ago
The caloric value of protein is (essentially) negligible. In what sense? Protein gets you about 4 cal/g like carbohydrates. I agree that the amount of protein we ingest is much smaller than the amount of carbs, but certainly not negligible.
- will_work4tears 14y ago
  Not the person making the claim, but it's more like 3g with TEF taken into effect, and combine that with the satiating effects of protein, it isn't very likely that people are going to eat 2000+ calories of protein. Even if you consume it in vast quantities like many bodybuilders, 300g of protein is only 1200 calories, ignoring TEF. Eat 1200 calories of protein and see how hungry you are for even more. Not quite "negligible" but food for thought. (pun intended)
Goladus 14y ago
The main issue I have with the paleo example and banning of processed foods is that it neglects to explain people who can eat processed foods in moderate quantities without getting fat.
jonnathanson 14y ago
The big issue, addressed in part in the linked article, is that processed foods have been engineered to fool the body's natural hunger and satiety signaling. They've been relentlessly tested and optimized to maximize enjoyment and minimize fullness or desire to stop (this point on the curve being the so-called "bliss point" alluded to in the article). It's possible, and perhaps likely, that the body treats processed fats very differently from natural fats. But the real crux of the issue is everything the fats come packaged in. In an almond, the fat comes packaged with a lot of fiber, a decent amount of protein, and a host of other nutrients. In a handful of Cheetos, the fat comes packaged with an array of chemicals designed to circumvent satiety signals, plus a lot of salt, sugar, and other goodies thrown in for good measure. Dietitians like to draw comparisons between, say, the nutritional profile of a single serving of almonds vs. the nutritional profile of a single serving of Cheetos. But who eats just one serving of Cheetos? That's the real issue. It's pretty hard to eat natural foods to excess; it's exceedingly easy to eat artificial foods to excess. In other words: it's not simply that artificial ingredients, in and of themselves, are bad. It's that artificial ingredients are intentionally combined in ways to increase caloric density and decrease the brain's recognition of said density.

by scythe 14y ago

BlackJack 14y ago

The caloric value of protein is (essentially) negligible. In what sense? Protein gets you about 4 cal/g like carbohydrates. I agree that the amount of protein we ingest is much smaller than the amount of carbs, but certainly not negligible.

will_work4tears 14y ago
Not the person making the claim, but it's more like 3g with TEF taken into effect, and combine that with the satiating effects of protein, it isn't very likely that people are going to eat 2000+ calories of protein. Even if you consume it in vast quantities like many bodybuilders, 300g of protein is only 1200 calories, ignoring TEF. Eat 1200 calories of protein and see how hungry you are for even more. Not quite "negligible" but food for thought. (pun intended)

Goladus 14y ago

The main issue I have with the paleo example and banning of processed foods is that it neglects to explain people who can eat processed foods in moderate quantities without getting fat.

jonnathanson 14y ago

The big issue, addressed in part in the linked article, is that processed foods have been engineered to fool the body's natural hunger and satiety signaling. They've been relentlessly tested and optimized to maximize enjoyment and minimize fullness or desire to stop (this point on the curve being the so-called "bliss point" alluded to in the article). It's possible, and perhaps likely, that the body treats processed fats very differently from natural fats. But the real crux of the issue is everything the fats come packaged in. In an almond, the fat comes packaged with a lot of fiber, a decent amount of protein, and a host of other nutrients. In a handful of Cheetos, the fat comes packaged with an array of chemicals designed to circumvent satiety signals, plus a lot of salt, sugar, and other goodies thrown in for good measure. Dietitians like to draw comparisons between, say, the nutritional profile of a single serving of almonds vs. the nutritional profile of a single serving of Cheetos. But who eats just one serving of Cheetos? That's the real issue. It's pretty hard to eat natural foods to excess; it's exceedingly easy to eat artificial foods to excess. In other words: it's not simply that artificial ingredients, in and of themselves, are bad. It's that artificial ingredients are intentionally combined in ways to increase caloric density and decrease the brain's recognition of said density.