I believe the theory that humans are biologically predisposed to crave sweet/fatty foods, because once upon a time our survival depended on getting enough calories…
But why do we thrive in sun, and get depressed on rainy, dark days? How did those traits prevent our extinction?
Just wondering.
shoes and pie 
…
But rainy days are the bestest…
At least in Colorado the rainy days happen so little that one can actually appreciate them (though when it’s cold it still sucks to walk in it)
How do you explain craving protein the day after a workout?
I notice I crave fat/sweets more in the winter, seems my body is wanting to insulate itself. It won’t believe me when I say it’s insulated enough.
Perhaps it’s not that the effects of the sun prevented our extinction so much as it’s the fact that the sun has always been part of our lives?
We used to live outside. Houses are new. Sure, we might go sleep in a cave; but we used to spend our days hunting, gathering, and playing outside with the plants and animals.
Our bodies learned to count on a certain amount of exposure to the sun. It evolved to use the sun’s energy to keep itself running smoothly.
The sun is a regular source of electromagnetic radiation. We know that our bodies use the sun to create Vitamin D. Who knows what other things our bodies might use the sun for?
We may be able to live without the sun. Our bodies may be able to compensate… However, it seems we’re currently engineered to run better with a little exposure.
… because you’ll catch a cold if you go outside the cave in the rain. That’s what my Mom would have said if she’d been a cavewoman…