You've got the muscles, they're just buried under a few extra pounds of cushion. No problem: there is an easy solution that will let you look buff without actually eating vegetables and (God forbid) drinking less beer. Starting buying your shirts a size or two smaller and everything will stay exactly where you want it. If you buy them small enough, you'll have another benefit: cutting off circulation will give your body a ethereal, almost ghostly look, as though you're an extra from Twiglight. There is really no reason to buy shirts that fit you when you can be staging your own free gun show day in and day out underneath your v-neck tee.
Wear a tight shirt to show off your physique.