A good night’s sleep is vital to keep you happy, healthy and focused the next day. But eating too late at night will have you tossing and turning. “Sometimes the food that you eat can interfere with your sleep,” warns Taub-Dix. Foods that contain caffeine—a few scoops of coffee ice cream, say, or dark chocolate—can make you feel more alert; high-fat or high-sugar snacks can also energize you just when you want to be winding down.