Pack a healthy snack. If you go too long between meals, you might be more prone to feast on high-calorie foods when you do eat, says a study in the October 2011 Journal of Clinical Investigation. In a small study, participants looked at pics of low-cal and high-cal foods (like ice cream sundaes) between 2 and 4 hours after eating lunch and had their brains scanned. Researchers found that participants were much more interested in the high-cal foods when their blood sugar levels were low versus normal. Satisfy afternoon hunger—and avoid those tempting but less-healthy options—by planning ahead.