"If you can't pronounce all the ingredients in a bar – or if it has high-fructose corn syrup, artificial sweeteners, or other artificial flavorings, colorings, preservatives, or additives – pick another bar!" says Dr. Suzanne Nelson, director of UC Berkeley's sports-performance nutrition department. Steer clear of anything "hydrogenated," which is code for trans fats. Added sugar can be hard to spot (brown-rice syrup, agave, sorghum syrup), but do your best to pick bars that don't list a sweetener as the first ingredient. It's also important to avoid artificial sweeteners, which hide under the names sucralose, aspartame, and acesulfame-K. Some bars add gelatin or collagen to up protein, but these sources don't contain all essential amino acids. And watch out for bars that contain soy, which can mimic estrogen if you eat enough of it.