Help?

Okay so me and my boyfriend were talking and he has started to workout says he wants to get rid of his belly fat to get a six back I told him but I like you the way you are (he struggled to gain weight from the beginning of our relationship) and now he has weight and not that much but he wants to get rid of it he's saying I'll love the change but I'm scared I won't what do I do? Do I help him reach his dream body or do I tell him I love how he looks now?