Many couples are unhappy due to the fact that their significant other is overweight. This causes physical and mental attraction to fade. You may think that asking you girlfriends is selfish; in reality, it is selfless if you do it in the right way. If your intentions are pure selfish, then your response will probably not what you hoped for. If you ask your girlfriend to lose weight for the right reason, you may just get the point across without hurting feelings.