Im sure if this is the right place or not so please move if it is not.

I have a very happy go lucky boy of 7 yrs who over the last 2-3 wks has started getting funn with eatting a meal at night he will eat during the day ok but does not want to eat at night he says that he is fat & chubby when he is under weight at 49lb he will never be big as neither my husband or me are big but I have an ED & this is were it has come from & i hate my self so much for it he has also said that he wishes he is dead sometimes as well which is very upsetting as he his my baby but he only says that when he has had a big fight with his older brother PLEASE help me as I dont know what to do