Burn fat in the dark. Seed magazine at www.seedmagazine.com/news/2006/01/fatburning_in_the_darkscientis.php has a piece that says there is a connection between darkness and metabolic fuel switch, that extended periods of darkness cause a state similar to hibernation, turning the body into a fat-burning machine, i.e., darkness acts as a metabolic signal and that extended periods of darkness cause the release of an enzyme, switching the body from being glucose-fueled to being fat-fueled. They suggest this discovery may be a new to treat obesity and type-2 diabetes.