How high is the percentage of obese people have eating disorders?

Eating disorders: Hard to answer as there are few studies, but the prevalence rate for anorexia nervosa is 0.3% and the prevalence rates for bulimia nervosa are 1% and 0.1% for young women and young men. Since roughly 30% of our population is obese, it would suggest that a relatively small number have eating disorders, though this isn't accurate since many have undiagnosed eating disorders.

Great question: Many people with binge eating disorder are overweight or obese, but i couldn't find any studies looking at the frequency of binge eating disorder in obese people. (not all obese people have this problem). Another category might be people with night eating disorder -- these people range from normal weight to obese. No studies of this correlation, either -- so both are interesting research topics.