Up all night hand-embossing your ceremony programs? Find a dutiful friend to fill in and get some sleep! When we're sleep-deprived our bodies produce more ghrelin, the hormone that tells us when to eat, and less leptin, the hormone that tells us when to put down the fork. It's a diet-destroying combo, especially if you're reaching for junk food. Salty snacks make you bloat, not to mention the fact that eating foods with no nutritional value can leave you feeling sluggish, says Gans.
Sleep deprivation also affects your immune system. "You're more likely to get a viral infection if you haven't been getting enough sleep," says Dr. Frank Lipman, an integrative and functional medicine physician and founder of Eleven Eleven Wellness Center in New York City. Logging enough shuteye also improves your complexion, rids your eyes of dark circles, and—let's face it—makes you a happier, calmer bride. (Your bridal party will thank you.)