Body dysmorphia

My incredible boyfriend has body dysmorphia. He used to be very fit and muscular but now since he doesn’t hit the gym anymore his muscle tone has decreased and his body fat increased. I still see him and they strong, attractive man I first met. I want to help him see himself in a better light, I have done some research on how to help but he doesn’t want to seek professional help ( he thinks it’s not a big deal). I always tell him how much I love him and how amazing he is but he thinks I’m just telling him want he wants to hear, he doesn’t understand that I see him as my Prince Charming. I was wondering if anyone that has or is still dealing with this problem or knows someone that had has any advice other than just me complimenting him (ex: I love your body it’s the same body that I fell in love with. You’re so strong.) or massages to hopefully make him more comfortable in his skin.