It's a very delicate subject. You don't want to just put it right out there and say, "Honey, it looks like you've been putting on a few pounds. What's wrong with you?" Instead, suggest exercising with your partner together. "Why don't we go out on a short walk today? We could make our date night a Sunday morning walk on the beach or a jog in the park." Hopefully your partner will be open to that. If not, there are very gentle ways to say, "Look, I am concerned about you. I've noticed that you have put on some weight. I love you, and I am worried about you. Is there anything I can do?" That's a more delicate way to say it, I would think.
