HEY I AM 13...PLEASE SOMEONE HELP ME REDUCE WEIGHT?

hi everyone...i am 64 kgs and i feel really embarred about my weight.my friends kind of make fun of me behind my back,and i really hate that.because of my weight problem,i cant concentrate on my studies and my grades are average.i want to reduce at least to 50 kgs.i want to surprise my friends.i need help in reducing weight fast.....anyone ready to help?