I'm probably in a minority in that I'm actually relatively small for a man, both my height and my weight. I eat just about anything and I don't gain weight. I have a little bit of a man-gut but the corset takes care of that.
With that said, I have found myself lately, especially as I get closer to forty, watching what I eat, and exercising a little more. I eat a lot more salads than I used to, and I would take walks in the evening over the summer.
I am very physically active both on my job and in my social life, so I've never worked out the way many people do, but I am more and more conscious of taking care of myself. A lot of it's just staying in shape, but a lot of it does have to do with my femme presentation.