Even an athlete who trains as hard as brady can enjoy during the offseason, put on 5 to 7 lbs and quickly lose..
Brady was once rail thin, so he may be a person who actually has to work to keep weight on. However, as a guy who's the same age as him, I can tell you that as you get older, its a never ending battle to keep it off for most people! Any time I twist something in my back or legs and have to take a couple weeks off from working out, I'm 5 lbs heaver than when I left off.