think my brother has a problem

so my brother is 12 and he’s a bit on the heavy side when he was younger he used t be really skinny and now he eats A LOT he’s greedy and hides his food and drinks in his room , he eats other peoples things sneakily without asking , he eats when he’s bored and i’m actually sick of it because my family’s going through a hard time and they are trying their best to be able to support for us , but that’s hard when they’re constantly buying food and drinks. They know he has this problem and even the doctor gave a prescription to see a weight doctor they don’t seem to be doing anything with him now though,