i dont really think its an eating problem u have. unless ur very muscular, 240pounds at 13 isnt really caused by eating unless ur like those people who have mcdonalds every day and tend to drink more coke than water etc. u should go to a doctor because as whisper said, thyroid problems can cause things like this. you may have a condition that u dont know about, are there any other people in ur family(sister, brother, mother, father, grandparents, uncles, aunts) that have weight problems? because it may be genetical and maybe u think ur eating less but what ur eating is high in colesterol so check what ur eating.