This is probably something that almost everyone believes: to lose body fat, you have to eat less. But with everything that has to do with how the body works, it’s almost never black and white. Instead, it’s always more subtle than that, it’s always a spectrum of shades of grey. And as I mentioned in the previous post, it is true that the amount we eat both does and doesn’t have to do with fat loss.
On the one hand, there’s no way that the body is going to use fat reserves unless it has to. If you’re constantly eating and digesting, supplying the body with a continuous stream of nutrients, it will never need to use its own energy reserves stock piled in fat cells, which need to be kept in case of need when we run out of food for a while. On the other, when we eat less, the body burns less, because metabolism slows down to adjust to the income energy supply. It’s also true that when we eat more, we burn more as the metabolism speeds up.
The effect on the metabolic rate of the amount of food we eat is in fact very significant. There’s a landmark experiment that was designed to verify that in a perfectly controlled setting of a prison that Gary Taubes reports on in Good Calories, Bad Calories. What they did is have a group of inmates increase their food intake and monitor body composition. But they increase their food intake in a very specific way: they had them on a low carbohydrate diet, increasing only their protein and fat intake. What happened was quite stunning, for most observers: despite an important increase in total calorie intake, nobody gained body fat. Mostly, they just felt really full all the time.
Good Calories, Bad Calories was read by a lot of people, and triggered a huge wave of interest in carbohydrate restriction, both in the research community and in the general population. Because it is so unbelievable to most that you can eat so much and not gain any body fat, the experiment was repeated by several people in recent times. And although these are what we call anecdotal, because they aren’t controlled experiments, they are still very interesting to witness. Here’s one that triggered several others to try it. It was done by Jason Wittrock who doubled his calorie intake from 2000 to 4000 for 21 days in a row, keeping his daily exercise and work routines the same, and maintaining the same very-low carbohydrate keto-style macronutrient ratios. He didn’t gain any fat or even weight: https://www.youtube.com/watch?v=MRop_ltYUlk
The essential takeaway is this: fat gain is not really related to how much we eat. Rather, it has mostly to do with the hormonal effects of what we eat.
G. Belanger, PhD — Kalibra Co-Founder and CSO