Time Change & Hunger
Why are you so hungry when daylight saving time starts?
Essentially, it's simply from that hour of sleep you lose when the clock springs forward while you're sleeping that messes with your body.
In 2012, researchers (their study was presented at the American Heart Association's Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2012 Scientific Sessions) examined the sleeping habits of adult men and women over the course of a week and found that those who were told to cut an hour and 20 minutes from their typical sleep time consumed an average of 549 extra calories per day. (FYI - that's what you'd find in a fast food hamburger).
Mohsin Maqbool, MD, Medical Director of the Pediatric Sleep Institute in Plano (a department of Texas Health Center for Diagnostics & Surgery) explains that lack sleep makes leptin levels drop (the hormone that makes you feel full) and that increases appetite. “When we are sleep-deprived, our brains respond more strongly to junk food so high calorie comfort food will seem appealing. However, healthy alternatives with protein, for example, may be just as satisfying.”