I think you just have to be comfortable in your skin. But, I'm a nudist in any case. I've never had a problem with my body and I don't really care what people think, so I have bottoms on and pretty much go topless, or also when we shoot - we did a lot of nude pictures today, too - it doesn't bother me in the slightest.
It's not difficult for me to stay healthy. I like healthy food. It's also become a lifestyle for me and I need a certain fitness level to be able to travel and have good skin and nails. If I ate worse then it would be difficult for me to keep up and it also wouldn't be so good for my looks either.