Building abs is about more than just exercise; your diet is crucial in achieving a defined and toned midsection. To attain well-defined abs, you must cut down on excess body fat and build abdominal muscle through proper diet and exercise. Certain foods, such as lean meats, soy products, and nuts, are known to promote ab definition. No single food can support body fat reduction; however, a calorie deficit is needed to lose body fat. A few foods may help in this process.