childhood obesity

My research paper is about factors that contribute to childhood obesity. At first my question was about how food advertising alone affects childhood obesity, but as I was writing the first draft of my paper and did more research on the subject, I realized that advertisements aren’t the biggest cause for it. It was also hard to just find articles about food advertisements so I’ve been researching more about childhood obesity as a whole and all of the factors that go into it. One source I found gives statistics on how much childhood obesity has risen in more recent years and gives a few examples of factors that affect it.  This source is helpful providing basic background on the subject that’s helpful to know before doing more in depth research.
http://www.apa.org/topics/kids-media/food.aspx