As many of my patients will remember, I used to be a big advocate of low-fat eating for weight control and health and to some extent I still am but with many more reservations. You can read here why I gave up preaching the gospel of low fat.
Since fat is the most calorie-dense macronutrient, it stands to reason that avoiding it makes food less caloric and this is true even for pure macronutrients. For example, a pound of oil has more than twice the calories of a pound of sugar. But if we add to this the fact that healthy low-fat eating should involve the sonsumption of a lot of high-fiber plants and fruits, then we are talking about food with extremely low calorie densities. Nearly everyone has heard the claim that it takes more calories to eat and digest celery than are contained IN the celerly and whether thiis is strictly true, the point is the same: plants generally have a very low calorie density because they are composed of water, fiber and mostly carbohydrate. So this brings me to the first point about low-fat diets:
This is true whether a diet's primary focus is upon fat grams, calories or carbohydrate. Indeed I think that the science of modern nutrition has been led astray by its over-emphasis upon the molecular nature of macronutrients. The more import issue than macronutrient composition is much simpler: plants are good for us. This is why I still like rational low-fat diets such as the kind recommended by Dr. Dean Ornish.
The problem with "pure" low fat diets is that they allow for the consumption of a lot of sugar and high-glycemic starches and there is just far too much evidence in the modern scientific literature that sugar at least is very harmful to human health and is obesigenic.
Again, plants are good. This is what good low fat and good low-carb diets share in common. In the end, as matters stand today in the year 2012, the sort of diet that seems to make the most sense to me is the one with a very silly name: the so-called "Caveman" or "Paleolithic" diet and I'll have a lot more to say about that shortly.
FAT SCIENCE > Nutrition and Weight Loss > Diet and Dieting > Macronutrient Restricted Diets >