Here is an article looking at factors that lead to teen obesity:
http://www.helium.com/items/1963966-why-obesity-is-becoming-a-problem-for-teenagers
and here is an article offering tips to deal with it:
http://health.ezinemark.com/overweight-teenagers-here-are-some-weight-loss-tips-169099ef5fb.html
And here is the study proving a link between teen obesity and adult obesity:
http://topnews.net.nz/content/29805-obese-teenagers-have-higher-risk-becoming-obese-adults