Fast food, candy, parents, autocontrol and sometimes the person has other health problems that cause the obesity. Fast food is really, in my opinion, one of the major factors that contribute to the obesity. The last time i ate fast food like Mc Donalds was months ago, because I love chinese food and I always eat it when i'm going out (and its rare). But I think that we need autocontrol and eat what we can when we can. Soemtimes what's tasty isn't good. Also, do exercises is good to health, instead of the ppl being fat or not.