Lack of sleep linked to obesity.

• Position: Weight Control - Brief article

Can lack of sleep make you fat? A study by the University of Chicago (Ill.) reveals that inadequate sleep is linked to obesity. The research explores how lack of sleep can impact appetite regulation, impair glucose metabolism, and increase blood pressure.

"Obesity develops when energy intake is greater than expenditure. Diet and physical activity play an important part in this, but an additional factor may be inadequate sleep," notes biomedical anthropologist Kristen Knutson. "A review of the evidence shows how short or poor quality sleep is linked to increased risk of obesity by deregulating appetite, leading to increased energy consumption."

Signals from the brain that control appetite regulation are impacted by experimental sleep restriction. Inadequate sleep--less than six hours a day--impacts secretion of the signal hormones ghrelin, which increases appetite, and leptin, which indicates when the body is satiated. This...