When I first started dating my husband, I gained a few lbs but he was the one that noticed first for himself. He said he gained weight and he had gained 5 lbs. We had been going out to eat quite a bit, especially Indian food. So basically we cut back on Indian food and made a few other changes.
I second the notion of giving up baking! I gave it up years ago. My best girlfriend bakes and I cook, so we have lovely meals together. There's just so much more to cooking than sweets! And it isn't healthy for him, either.
Is he trying to sabotage? or just not understand how your body works? I agree with the others. Sit him down and tell him what you are feeling and how he can help. Maybe ask him to 'problem solve". Most guys like to do that.
Good luck with keeping your communication lines open.