First of all, Don't worry about what your friends look like because they are NOT you. Another thing is, if you seriously want to lose pounds, participate at P.E. and also start an excercise routine at home. You can do the same excercises you do at P.E. at home, and then go for a jog. Also, you can start substituting the junk food you eat and grab a piece of fruit. Or if at lunch you're friends always eat the school lunch try bringing you're own.