[goda90]

Vitamin D is fat soluble, so it would be feasible to build up a supply in summer to last through winter. I've seen it theorized that a cyclical weight gain and loss tied to preindustrial seasonal food availability also plays a role.

[spacington]

People tend to fatten up on winter and peaking at around winter solstice

Not sure how your plan should work?!

[goda90]

Because of industrial food chains making that possible. Before we could refridgerate and ship food all over, most of your calories came from seasonal foods, and summer is usually more bountiful than winter.