In the study, people who ate apples before they shopped bought 28 percent more produce than consumers who had cookies. They also bought fewer unhealthy items. MORE: 4 Snacks You Can Actually Binge Eat The explanation is simple: Once you eat a healthy snack, your subconscious continues to steer you in the same direction, says study author Aner Tal, Ph.D.   That’s good news for your waistline: Instead of consciously trying to change your behavior, this kind of priming helps you make healthier choices with basically no effort, he says. MORE: Is Farmers Market Lettuce Really Better Than Begged Lettuce at the Supermarket? So before you hit the aisles, chow down on a wholesome snack. Just make sure you don’t dawdle around after eating—the effects of priming lessen over time, so the trick really only works if you have the snack right before you head to the store, Tal says. The article “How Eating One Apple Could Help You Eat Healthier for a Week” originally ran on MensHealth.com.