When I do photography I look for natural beauty not weather you can show your abs. If you get naked for me or not it's about telling a story or being creative and I consider anyone for a shoot and hate that the media labels women and men for that matter on how you should look and feel.
I am a skinny ugly guy according to the media yet in reality I feel normal. I am not a gym freak it's just naturally who I am. Just be yourself. You are not out to prove the world anything. You should only please yourself and a handfull of others who make you smile. If you happen to get famous or impact a wider audience good for you but that shouldn't be your goal.