How did Kelly Osbourne lose 50 pounds so quickly?

I am 12 years old, "4'11",118 pounds and my body is absolutely DISGUSTING. I measure 32-30-35, and 34 inches around my belly on, which I am trying to lose 10 inches from. I am fine with my arms, my legs, my chest and my rear end, but I HATE my gigantic jelly belly, love handles and muffin top. I can't fit any pants that don't have an elastic waist band, which is odd because I eat about 800 calories, 90g of carbs, and 30g of sugar which is about a third of what all of my friends eat, and they are skinny AND curvy (estimated measurements: 35-22-32.) I have tried almost EVERYTHING but nothing has seemed to work.