(versión en español: pinchar aquí)
At the risk of stating the obvious, the quantity of food in your diet has a strong impact on weight. The composition of your diet, though, seems to play little role in weight—a calorie is a calorie, regardless of its source. (see)
— So, those experts say the specific diet is not that important, what matters is the amount of food you eat
— That’s exactly what they say
— Therefore, controlling your appetite and compliance with the caloric reduction are the only ways to lose weight
— That’s exactly what they say
— But you think otherwise…
— I do. In the first place because everybody knows that that doesn’t work (see). Let me ask you a question. Imagine I feed you for 35 days. I start giving you 2700 kcal/day for 5 days, then 3600 kcal/day for another 5 days, and I keep increasing the Calories every 5 days until you reach 6000 kcal/day for the last 10 days of the study. What do you think would happen with your body weight?
— It will increase, no doubt about that. Those calories go way beyond a normal person’s caloric intake. It can’t be otherwise: you get fat.
— Is it possible to lose weight eating that much?
— No, it isn’t. Isn’t that obvious?
— In fact, that experiment has already been done (see), and you can lose weight. But you can also gain weight. The outcome depends on what you eat. I show you the weight evolution (red) and the caloric ingest evolution (blue) for a specific diet. The subjects did lose weight in the experiment.
— How is that even possible? Isn’t that result against the thermodynamics’ laws?
— That’s nonsense: no real-life result can be against the thermodynamics’ laws.
— May be they ate a lot of protein and that result is a consequence of the thermic effect of food?
— Protein content was held constant along the experiment: 64g/day
— What happened then? I don’t understand.
— Read this and you tell me.
— Done. Did their bodies get hot or something like that, to get rid of the extra Calories?
— That is exactly what the researchers concluded. The subjects were eating a high proportion of dietary fat and, according to the researchers, «when the daily fat intake reached levels of 300 to 400 g/day, all subjects reported a strong and persitent sensation of heat«. They also said: «it would apear justifed to conclude that under a low carbohydrate, high fat diet regimen, an increased energy output takes place, which is emited in the form of heat.»
— That’s just unbelievable
— No, it isn’t, once you realize how wrong the energy balance theory is. But I wanted to tell you more: in the same study they also used different diets on obese subjects and they observed that the subjects lost approximately the same weight per day eating 2150 kcal/day on a low carbohydrate diet, than on a calorie-reduced diet (1000 kcal/day). In fact they lost more weight with the low-carb diet: 320g/day -vs- 260g/day. One last thing: if in the low-carb diet fat was exchanged isocalorically for glucose, there was no weight loss.
At the risk of stating the obvious, you can’t trust the «experts».