Interesting article by my friend and doctor, Phil Wagner.
"At Sparta we tell our athletes to make their rooms like a cave; cold, dark, and quiet. At first, it was just the theory that our ancestors slumbered in a similar environment. After all, since our nutrition should be focusing on the primal nutrients found in protein and vegetables (seeSpartaPoint 4/14/10), an approach known as the Paleo Diet, shouldn't our sleep mimic the same philosophy?
Recent research has actually supported these cave recommendations, particularly the most important aspect, darkness. A 2010 study out of Ohio State University examined the effects of nighttime light exposure on mice. Despite equal caloric intake and daily activity, the rodents exposed to light at night had significantly greater weight gain. This weight gain was attributed mostly to a larger percentage of food consumption at night. In the nighttime light exposure group, more than half of the day's intake actually occurred late in the evening!"