If you have an issue with regularity, then you can do all the cardio and crunches in the world, and you'll still have a little belly pouch. That's because constipation can cause bloating, which will make your belly appear slightly swollen. It's normal to have issues with going to the bathroom every so often, but if you suffer from constipation daily, it can make your middle wider than it needs to be. The solution? Up your intake of soluble fiber. Include apples, pears, berries, oats, quinoa, beans, carrots, cucumbers, and celery in your diet every day. This type of fiber soaks up water and forms a gel-like substance that stimulates the muscles in your digestive system, and helps push things along. Eating enough fiber will not only make you feel better, but it'll help flatten your belly.