My husband is 6'2" and has weighed about 175 for the past ten years. Before that he varied somewhat and may have been as high as 200 (which still isn't very high for his height). The change has come about from his adopting an avid exercise program, which he manages to fit into his day despite long hours and a long commute. He usually works out before work (which means leaving the house around 5 a.m.). I have had very mixed feelings about his routine, which I think borders on exercise-anorexia. I have also joined the gym, which gives me a bit more perspective, but I don't enjoy it the way he seems to. He says that because he works out so early in the day, it doesn't interfere with time he would otherwise spend with the family. There is some truth in this, although on the weekend he can spend as much as 2-3 hours at the gym (long cardio sessions followed by weight training), or sometimes he breaks it up and goes to the gym twice, or rides his bike and then goes to the gym for weights. Get the picture?
When I have asked him why exercise is so very important to him, he says that it makes him feel younger (he is 51) and thinks it helps give him sexual stamina (which I have to admit, he does have!) From what I can tell, he eats very little during the day, then has a substantial but not huge dinner, including wine and often ice cream or other dessert.
To his credit he has never complained about my weight gain, and has supported my new WOE, despite his own preference for the old food pyramid proportions. I also figure there are a lot worse habits for husbands to have than exercising too much.