Polycystic ovarian syndrome, which contributes to obesity in women, seems to have adaptive advantages in famine of the type speculated upthread (and also including increased fertility then, though decreased fertility in abundant food situations.)
It's not too much of a stretch to consider that there may be metabolic conditions in men linked to obesity risk that have the same kind of advantages in reduced-food-supply situations.
it is also depends on how much more energy one has to expend to haul that stored energy around.