There are a few things that will help lessen a poochy tummy; first, practice good posture; stand and sit up straight while keeping your tummy in. Second, always breathe through your chest so your ribcage expands; this helps distribute air throughout your entire body so it's not trapped in your stomach. Third, never eat until you're stuffed or go to sleep right after eating; eating too much can expand your stomach muscles, which can stretch your tummy and make it appear poochier.