Eating disorders are often thought to be a “rich white girl’s disease,” but a new study shows that black girls and girls from low-income families are more likely to develop bulimia than their wealthier white counterparts. The study is based on information from a government database of 2,300 girls from schools in California, Ohio and Washington D.C. The girls were surveyed annually about their eating habits and body image between the ages of 9 and 20. The study included an equal number of blacks and whites.