There is a form of diet that is not related to weight loss primarily. It is a diet primarily designed for utilizing autophagy called intermittent fasting. To do a full-calorie restriction diet is a hard choice.
What happens when our regular metabolism burns energy for life? Some of that energy escapes and does damage to DNA. The higher the metabolism, the higher the damage, and the higher the division. Every time a cell divide it clips the telomere in half.
We all want to have muscle mass as much as possible and fast metabolism as much as possible so that we can eat and don’t gain weight. The question is how normal is this and what is the price of constant eating with no restriction even if we don’t gain executive weight? Evolutionary biology will again tell us what is healthy.