It's not easy, I was there. I actually made a similar confession on reddit and I got some good advice, that now I'll pass on. People told me to keep healthier food in the house, suggest we be more active (e.g. take long walks just for fun), and go to restaurants that had healthier options and order them for myself.

At first, I thought it wasn't going to work. He either seemed to ignore what I was doing or seemed annoyed that I wanted to walk all the time, or I didn't want to go to the same heavy restaurants, or share the food we ordered when he got fattening stuff. But eventually, bit by bit, he came around.

Now we walk together all the time and he says he really likes eating healthier, but he still needs his fix of rich desserts or Italian food once in a while. It took quite a while, but the weight really did come off and he says he feels much better.