A stomach pooch is unsightly, but it's not uncommon. Aging, eating too many sugary, starchy and fatty foods, not getting enough exercise and other lifestyle factors, including stress and lack of sleep, can all lead to excess tummy fat. Abdominal exercises won't work when your goal is to reduce belly fat. You can do hundreds of crunches a day, but if you have a layer of belly fat covering your ab muscles, you'll never see your hard work.