I was in the Naval Reserves several years ago - I'm short and stout (always have been to some extent), but got in OK, and managed to come out of boot camp looking pretty good. Hospital Corps school was a lot of eating fast food, and drinking beer, yet I didn't have any problems keeping thin (and making the top of my class). Field Med School was a different story - I spent 2 months playing with Marines, and managed to gain 15 pounds (of fat, not muscle), and I never lost it. Finally after several years on the "Fat Boy" program, I was finally honorably discharges at the convenience of the Navy because of my weight. I later found out, that the active-duty corpsman and the Reserve Center CO had been processing waivers to keep me in, because I was damn good at my job. But I was fat, and when a new CO took over, I was let go. 6 months later the first Gulf war started, and nearly all of my reserve unit got called up and sent to the Gulf.

I was glad to be a fat boy then...