As we age, sleep becomes less deep and more fragment. People who are obese are more likely to have poor sleep due to sleep apnea. I often take melatonin 2-4 mg a bedtime to help with my sleep, especially when traveling across time zones. Suppression of natural melatonin release may contribute to obesity. The video below from the Wall Street Journal addresses the question of whether melatonin supplementation (available over-the-counter) can help folks sleep better.
Obesity: Melatonin is involved in energy metabolism and body weight control in small animals. Many studies show that chronic melatonin supplementation in drinking water reduces body weight and abdominal fat in experimental animals, especially in the middle-aged rats. It is interesting to note that the weight loss effect of melatonin does not require the animals to eat less and to be physically more active. A potential mechanism is that melatonin promotes the recruitment of brown adipose tissue (BAT) as well as enhances its activity. This effect would raise the basal metabolic rate by stimulating thermogenesis, heat generation through uncoupling oxidative phosphorylation in mitochondria. Whether the results of animal studies can be extrapolated to human obesity is a matter of future clinical trials, since substantially active BAT has been identified in adult humans.
From the Wall Street Journal: