what mostly concerns me is that today is about the weight and tomorrow will be about something else....It's bad if people can affect his choices and his decisions like this....He should be proud of his choice and tell them to back off!
I suggest you to talk to him or email him and tell him that this is who you are and if he doesn't accept you like this then too bad.....
I'm pretty sure he will apologize you....because you are so sweet and unique