If you’re logging just a few hours of sleep a night, you may actually find yourself gaining weight. Researchers at the University of Chicago Medical Center found that subjects who slept just four hours had a harder time processing carbs. "When you're exhausted, your body lacks the energy to do its normal day-to-day functions, which includes burning calories efficiently," says Talbott.
Also some research shows that the human body is primed to consume most of its calories during daylight hours. But the lifestyle is problematic for many: Because family meals and dinners with friends often are scheduled for after sunset, “people who try to stop eating after 7pm can’t do it every day for the rest of their lives,” says Dr. Seltzer, who supports an alternative strategy: Eating a hearty meal at your regular dinnertime.