5 Foods That Flush Fat These 5 foods provided by Eat This, Not That! will help to rid your body of fat when combined with proper fitness and calorie-restriction. 1. Guacamole The B6 vitamins in avocados counteract the fat-building stress hormone, cortisol. 2. Oatmeal According to a Tufts University study, those who ate three or more servings of whole grains had 10% less belly fat than those who ate processed white carbs. 3. Sweet Potatoes Rich in carotenoids and antioxidants, sweet potatoes aid the lowering of insulin resistance, preventing calories from turning into fat. 4. Berries The polyphenol antioxidants contained in berries help to burn fat and also prevent it from forming. 5. Eggs Eggs contain a good amount of choline, a nutrient that helps to turn off the genes that cause belly-fat storage.