Normal shyness?

[Calanthe]

My ds (11rs) has become increasingly shy about his body- mostly completely normal I am sure. But it's got to the stage that he won't even change his T-shirt if I'm in the same room. Is it just me or is this a bit extreme?
Thanks

My DS went through a stage of this at similar age, i finally managed to coax out of him that he thought he was fat and he didn't want anyone to see his body.
He had/has a little puppy fat but nothing more. I would reassure him that he wasnt overweight and in time he's stopped being so shy of his body.
I would say it's completely normal but always worth double checking, perhaps its weight related or someone has said something to him to make him feel like that?