Experts say there are two basic categories of foods that can be considered "keeping it off superfoods" because they fill your tummy without piling on the calories: fruits and vegetables. And the nutrient that gives fruits and vegetables that staying power? Fiber. So, if fruits and vegetables are the "keeping-it-off superfood groups," fiber may well be the "keeping-it-off super-nutrient." Protein is another super-nutrient. It's becoming more scientifically accepted that protein may help to curb ...... more