5 Answers

Your parents should be getting him to eat a proper meal, not you. When he hits puberty and goes through a couple growth spurts he will probably lose the excess weight. You should not worry so much about him. You are not his parent. Mention it to your parents and let them worry about his weight. 

Your concern for your brother is heartwarming; so many siblings are at each other for the smallest indiscretions.
Colleen is right when she tells you this is not your problem, but something your parents should be addressing.  
I don't know if you are overweight, too, as your brother weighs only one pound more than you, or if you are several years older....
YOU can help your brother by letting him know you care about him and want him to be healthy and active.  If he is teased, you cal also say you sure don't like hearing people say stuff about him.  You can even ask about the two of you working on an exercise regimen.
Whatever you do, please don't put him down...it's a hard world to begin with, and being overweight doesn't make it easier.  

Glad to see you are health conscious, ask your parents to provide different foods, rather than the processed stuff.Your brother is only 10 so he is still a growing boy and needs 3 healthy meals a day.When he feels like a snack,  Instead of reaching for the noodles get him to have a piece of fruit , some nuts ,yoghurt ,cheese.Get him out of the house and kick a ball around as exercise helps also with weight management.

7.5 stones at ten in my opinion is not excessive , I have an eight year old who is 5stones and not an ounce of fat on her . At ten his body is about to change into a young adult and nature , along with his changing hormones will alter his body gradually turning any excess fat into new muscle etc. As for his diet get your parents to buy different foods and as much as he protests he dosen't like them when he gets hungry enough he'll devour them whatever they are if you only buy crap for him to eat he will only eat crap but if you buy only healthier foods he will have not any other option but to eat them as an empty tummy is very persuasive and eventually he will develop a taste for healthier foods although there may be some protesting in the mean time from him. Don't worry yourself he'll turn out Ok

There is other options other than noodles and sugar. The thing is when I do help he chooses not to listen and gets angry. I am a junior in school and I was sent at my grandparents house with responsibility on my shoulders. My dad told me to give whatever he wants and if he dosnt like it then i have to make something else.

Sometimes i feel like dying because of this...