Researchers at the University of Minnesota (where, 60 years ago, Ancel Keys did his pioneering work on starvation) are beginning to quantify the links between overweight and eating disorders in kids. Their newest study looks at the risk factors that make overweight teens vulnerable to behaviors that are part of eating disorders: self-induced vomiting, using diet pills and laxatives, and binge eating. They also look at socio-cultural factors that contribute--reading a lot of magazines articles about dieting, for instance.
The research is led by Dianne Neumark-Sztainer, who's done some excellent work on weight over the years. It's worth checking out, especially in light of our current hysteria around obesity and the plethora of intervention efforts aimed at kids, which I fear are creating a tidal wave of eating disorders. (They certainly don't make kids thinner.)
Thanks to Jane for pointing out this research!