Developed for athletes to keep them from running out of steam during competition, the pocket-sized energy bar has gone mainstream. “Energy bars are a convenient alternative for someone who would otherwise be reaching for a doughnut or using the vending machines for snacks at the office,” explains Liz Applegate, PhD, nutrition expert at the University of California at Davis. They are not a replacement for balanced meals, but combined with other healthy snacks—yogurt, bananas, walnuts—a good quality energy bar can help get you through your afternoon slump without spiking your blood sugar. Choose ones that are low in fat (4-7 grams) and have less than 230 calories. Look for real flavors over artificial flavors, and sugar alcohols (good carbohydrates) instead of sugar (bad carbohydrates). Make sure it contains some protein and at least 3 grams of fiber.