Two foods noticeably missing from celeb trainer Harley Pasternak's 5-Factor are grapes and bananas. Harley, who counts Katy Perry and Lady Gaga as clients, says, "No one is going to live a shorter life if they have bananas or grapes," but he recommends that his clients choose healthier fruits. "I tell my clients to stick to fruits that either have edible skin, edible seeds, or citrus — bananas do not have edible skin, nor do they have edible seeds really, nor is it citrus. Most of the fiber and nutrients that are in a fruit are in a fruit's skin. A banana is just the densest piece of fruit that you can put in your body, and since it doesn't have much fiber, it won't keep you full." As for grapes? "Grapes have a special sugar in them called dextrose, which is the highest glycemic sugar that you can possibly put in your body."