Not physically attracted to husband anymore

I love my husband but in the year we’ve been married he’s let himself go and gained a ton of weight. He doesn’t care though and continues to eat really unhealthily. If I cook and it’s something healthy he’ll order fast food. He always makes jokes about the weight he’s gained and doesn’t seem bothered by it at all. I’m not sure the exact amount but I’d say about 40 pounds.

I’m not attracted to him physically anymore but I don’t know how to tell him gently because I know if the tables were turned it would hurt me. Do I keep quiet or say something?