"Melatonin does help induce sleep to a moderate degree," says sleep specialist Steven Feinsilver, MD, which is why cherries, which are rich in melatonin, make such a good bedtime snack. According to nutritionist Dana James, MS, CNS, CDN, pumpkin seeds are also a great option. "They're rich in magnesium which helps to induce a deeper sleep by relaxing the muscles in the body," she says.
And finally, a good reason to get popcorn at a night movie: It's high in serotonin, the chemical responsible for regulating our sleep cycle, says nutritionist Keri Glassman, MS, RD. (air-popped is your best bet, since the salt and butter in packaged popcorn could cause you to wake up throughout the night.)