Getting a good night sleep of 7-8 hours every night can help you lose/maintain weight by affecting the hormones that influence your appetite.

How much you sleep and quite possibly the quality of your sleep can affect the hormones, leptin and ghrelin, that influences your appetite and thus your weight. Ghrelin, which is produced in the gastrointestinal tract, stimulates appetite, while leptin, produced in fat cells, sends a signal to the brain when you are full. A study conducted by researchers at University of Chicago found that sleep deprivation triggers a decrease in leptin (which means you don't feel as satisfied after you eat) and an increase in ghrelin (which means your appetite is stimulated).