get a girl that supports and will help you. if she isnt willing to maintain a hrealthy lkifestyle with u then she will end up fat anyway so ditch her. My wife goes on diets with me, not cause she needs to (she sheds weight much easier than me) but because she has really good will power and when we do it together she keeps me from cheating the diet. When we go to her parents we just make sure there is a healthy alternative, and if there isn't then we swing by Wendy's on the way and order Chili and chicken breasts for me, or a salad with no crutons or dressing. There is always a healthy alternative, you just gotta plan ahead and get creative