Two parts. "Honey, I love you just like you are. You make me happy and the best moments of my life are spent with you. So don't worry about your weight." Then, "Tell you what though, if your weight is making you unhappy, or if you are worried about how it might impact your health, then you and I will do an exercise program together. We are in this together." Use the words that best come out of your mouth, but that is the jist of where you ought to go. My younger brother married a lovely but overweight gal - and they have now had two miscarriages because of her weight. So there are some real health issues here. The trick is to make her feel accepted and at the same time convince her that it never hurts to keep your weight down and be healthy. Separate the two in her mind. You see her as attractive - but you want to keep her healthy and safe. That way you accept her - and you are trying to take care of her and will be with her. This will take diplomacy, but with sufficient tact, you can do it. Quick clarification - It might be best to split this up. When she asks how she looks, you praise her. Then, at another time, you might says something like, "You know, honey, you mentioned the other day that you thought you needed to lose weight. I've been thinking I could stand to lose a few pounds too, so why don't we start an exercise/diet program together?"

That is a loaded question and of course there is no good answer. . And one that speaks more of her lack of self-esteem than her weight. If you think she is beautiful then say that but turn it back to her. For instance "I think you're beautiful but if you want to lose weight then do it."

2-20-2017 I once wrote a list of answers to that question and I recommend you do the same. Twenty five years and only three good answers. Study these so you can whip one out without having to work at remembering it. #1-Do I look stupid? #2-Some gals are built for speed, some are built for comfort. You're built for comfort. #3-I see a few pounds I'm not legally married to.