IIRC the big problem with calorie restriction is that it brings along a greater susceptibility to infectious disease. After all if it were a cost-free win, a gr

IIRC the big problem with calorie restriction is that it brings along a greater susceptibility to infectious disease. After all if it were a cost-free win, a gradient-descending (is that the right term?) optimization process like evolution would have implemented it already. https://www.theguardian.com/science/blog/2009/jul/14/ageing-calorie-restriction-diet https://www.theguardian.com/science/blog/2009/jul/14/ageing-... Regarding suggestions made in another comment that calorie restriction represents the preindustrial norm, I don't think this is something modern nutritional science would have missed, considering the amount of research performed into the diets of extant nomadic and otherwise primitive cultures.