An estimated 5-10 million people in the US are affected by some kind of eating disorder. There are officially 12 types of eating disorders including the common anorexia and bulimia, but each is rooted in 3 common causes; biological, environmental and psychological. The causes for the eating disorders usually start from biology but can also arise from psychological and or environmental causes alone.
A lot of eating disorders arise first from a biological pre-disposition to developing an eating disorder and then are usually triggered by a psychological or environmental event or series of events. A common perception is that “Genetics loads the gun, environment pulls the trigger.” Some disorders though do not arise through genetics but instead sever trauma such as sexual abuse, especially as a child. The disorder arises, is this case as a coping mechanism. The abused seek comfort or control through food either as over eating, in the case of comfort or a strict diet in the case of control.
Racism and class standing can also contribute to eating disorders. Maybe not directly but because of the huge amount of stress accompanying the persons situation. I personally don’t see how racism and class standing can cause eating disorders except from the stress it can cause. Maybe if you lived in a part of the world were your race determined how much / what kind of food you get or that being poor may limit your diet but these are more social problems and not a disorder of the person.