Coruscation

A less-than-novel solution -- getting more sleep -- would also help.

The endocannabinoid system is involved in various brain functions, including stress management, immune response and pain modulation. It has even been linked to the "runner's high" that many feel after aerobic exercise. But the new study represents the first time that scientists have found the system to be affected by sleep deprivation, Dr. Hanlon said.

Research suggests that losing sleep slightly increases the body's need for calories, but that people who are sleep deprived often consume far more than they need.

The study comes as Americans are voluntarily curtailing their own sleep, a practice that may correspond to a sharp rise in obesity rates over the last several decades.

Between 2005 and 2007, nearly 30 percent of adults said that they slept six hours or less per day, according to data from the National Health Interview Survey. That's an hour less than the minimum amount of sleep recommended for adults.