Beautiful dreamer: lack of sleep could be causing more than bags under your eyes--how about that saddlebag around your waist!

Weight-watching guys who cut back on sleep time for early mornings on the StairMaster might do better to go back to bed. Studies say sleep deprivation can cause stark hormonal changes that contribute to carbohydrate cravings and, ultimately, weight gain--just what those early risers were trying to fight.

Fat cells in the body produce an appetite-regulating hormone called leptin. It tells your brain when it's time to stop shoving fries in your face. When sleep scientists at the University of Chicago restricted a group of volunteers to four hours of sleep a night over six-days, the participants' leptin levels plunged. Conversely, the sleep-deprived patients experienced elevated levels of ghrelin, a hormone mostly produced by the stomach that makes you hungry for flies in the first place. Not surprisingly, a mini carb-craving epidemic ensued.

The findings complemented the university's 1999 study that found sleep debt can actually cause the body to have trouble digesting carbohydrates, which is itself another risk factor for weight gain and even obesity.

Translation: Sleep less, eat more, digest poorly, get fat. Atkins devotees, it's past your bedtime.

"If people chronically chose to not get enough sleep at night, then that could make their appetites go way up, their consumption go way up, and that could lead to being overweight and obese," warns Jim Gangwisch, an epidemiologist at Columbia University Medical Center. He has conducted a study whose findings have shown that four-hour sleepers are 73% more likely to be obese than people who snooze a full eight hours. Five-hour-a-night guys are 50% more likely, and six-hour men are 23% more likely to have significant weight gain.

Before Thomas Edison perfected the light-bulb, people generally slept 10 hours a night. The average late-night-television--saturated American is now squeaking by with 6.9 hours on weeknights and 7 1/2 on weekends. Most people need a consistent seven to nine hours to remain happy and healthy.

Does this mean that self-indulgence could be the newest diet craze: Just get in bed? Maybe. Robert Vorona, MD, a sleep researcher at Eastern Virginia Medical School, warns that the findings are still relatively new and do not prove a cause-effect relationship between sleep loss and weight gain, just a correlation. He hopes to follow people in weight-loss programs to see if they can literally dream away the spare tire.

But if you're looking to try to make some life changes, it certainly couldn't hurt to do so while unconscious. If you're like 70 million Americans, you probably have trouble sleeping and may want to consult a physician about sleep strategies.

TAKE NOTE! A trick to help you fail asleep is to have a glass of warm milk with honey and a banana before bed. Milk contains the sleep-inducing amino acid tryptophan, which turkey is so famous for. The carbohydrates in honey help tryptophan get to the brain, and the banana's vitamin B6 aids in converting tryptophan to serotonin, which in turn makes you sleepy.