Back in middle school, I was large. My mom started cooking low carb and that worked really well. High school I was about 280. I went on my own diet I guess you could say. More along the lines of controlling what I ate. I ate smaller portions. Easy way to do that is pick a smaller plate to eat your meals on. I ate less junk and more fruits and veggies. I dropped down to about 220 in 6 months. Then I got a job working outdoors and i dropped down to about 185. Now after getting a job indoors, I went up to about 215:/
Best advice I have is to control what you eat and exercise.