I read somewhere and would love to give credit, but I'm not sure where I read it. The tropical is personal addition however. I won't recreate this theory as eloquently but the general premise is:
in the spring/summer meat was plentiful, we hunted and ate meat, to stay fit enough and athleticly light enough to hunt effectively, we burned the fat as fuel to have the energy to keep hunting and because we had more calories available soon, fat caveman doesn't hunt well
late summer/fall fruit bloomed we ate it and stored it as fat(as we know fructose does)and that gave us both warmth and fuel to survive the winters animals were scarce but coupled with scrounged veggies, fermented whatever, stored meat etc we made it thru winter. As spring hit we were lean from burning the weight over the winter and ready to hunt once more
the more tropical climates were winter was less a concern have fatty fruits like coconut and avacado..?? Coincidence or were they our way of staying trim year round with energetic sat. Fats?
Opinions? (please note original source of this theory if you can)