Todd Moody wrote:
> From a paleolithic standpoint, I tend to assume that the ability
> to store energy as body fat had a high value.  Fat not only is
> energy that can be used later but also serves as insulation.  The
> colder climates where carbs are scarce are precisely the climates
> where such insulation would be needed, so it would make sense
> that we should have an ability to make body fat even under
> low-carb conditions.
I tend to agree, except for one thing - the fat accumulation only
makes sense before food shortage. Fat accumulation on a continuous
basis makes an animal less survivable (clearly true for prey, to
some extent for predators too). I tend to think that this could be
part of the reason why gaining weight in response to carbs evolved -
high density carbs tend to be available before winter (seeds, fruits,
etc.) when fat storage makes sense. However it evolved, high carb
consumption and fat storage go hand in hand.

Ilya