Potatoes bad, nuts good for staying slim, Harvard study finds
The findings add to the growing body of evidence that getting heavier is not just a matter of “calories in, calories out,” and that the mantra: “Eat less and exercise more” is far too simplistic. Although calories remain crucial, some foods clearly cause people to put on more weight than others, perhaps because of their chemical makeup and how our bodies process them. This understanding may help explain the dizzying, often seemingly contradictory nutritional advice from one dietary study to the next.
Every time I read a study where they imply that energy isn’t conserved, it seems that they sneak in a caveat, like this:
Although the study did not evaluate why potatoes would be particularly fattening, other research shows that starches and refined carbohydrates such as potatoes cause blood sugar and insulin to surge, which makes people feel less satisfied and eat more as a result, Mozaffarian said.
Eating more = more calories consumed.
As someone who has lost a lot of weight on a low carb diet (and did a lot of research as well), it seems the answer is to do with the ease with which the body can utilize the energy. To use energy in fat form, the body has to expend more energy. This is similar to using oil that is sitting in a barrel, and using oil that is miles underground, that needs to be extracted and refined.
Another thing that should be considered is the calorie output of your body in the form of (ahem) stools. One weight loss drug seems to work by making fat indigestible which results in (rather nasty) oily/fatty stools.
Personally, I’d struggled with my weight for years, trying all sorts of diets, but could not successfully lose significant weight until I discovered low carb, then I managed to go from 107kg down to 83kg (almost my “correct” weight) in around 6 months. It’s certainly true that protein and fat makes you feel full and satisfied, which is one reason this diet works (and so easily at that). ymmv
Of course thermodynamics still wins. However, the issue is that the body is not a simple thermodynamic system – it is actually incredibly complex. The standard physics approach of assuming a spherical cow (calories in – calories out = weight gain) doesn’t work. The body has multiple energy conversion pathways depending upon the source of energy (carbs, fat, protein, alcohol), each with a different preferential weighting and hormonal response. In addition, there are feedback loops within the body particularly with respect to how energy is converted into glucogen or fat. All of this leads to the advice to “eat less and exercise more” being rubbish, as the article you refer to indicates.
The standard dietary guidelines of the U.S. are not based on science, either thermodynamics or physiology, and that is why we have gotten fatter since their implementation and not thinner.
My point is that the article isn’t showing that calories in – calories out is wrong when they admit they aren’t measuring this by saying that the weight-gainers eat more of certain foods. It’s also true of articles that conclude that exercise doesn’t matter because you eat more when you exercise — that doesn’t invalidate the equation.
Some foods may be more or less likely to fill you up and thus you eat more or fewer calories, but at the end of the day these articles have not refuted that your caloric intake and how much you burn is what matters. Dietary advice is ultimately about how you achieve that.
I was just talking about that article because I was flummoxed by it. It is unclear from the article if the patterns are causative or correlative. Do people who eat fruit tend to be more aware of their diet and portion size? This is a highly irritating article.