Good sleep....in pitch black.
Anyway, here is a study I spotted today - Lack of Sleep Makes Your Brain Hungry
"After a night of total sleep loss, these males showed a high level of activation in an area of the brain that is involved in a desire to eat. Bearing in mind that insufficient sleep is a growing problem in modern society, our results may explain why poor sleep habits can affect people's risk to gain weight in the long run. It may therefore be important to sleep about eight hours every night to maintain a stable and healthy body weight."
There is a journal referenced, but I can't find the article yet.
Acute Sleep Deprivation Enhances the Brain's Response to Hedonic Food Stimuli: An fMRI Study. The Journal of Clinical Endocrinology & Metabolism, 2012; DOI: 10.1210/jc.2011-2759