If you have ocd as a child, are you at risk for developing anorexia as an adult?

No: No, there are not scientific studies directly linking OCD with anorexia.

Yes, but...: Although there is an association with childhood OCD and anorexia nervosa, most people with OCD do not develop anorexia nervosa. Anorexia nervosa is, itself, a serious illness with inherent obsessive-compulsive features, so there is considerable symptom overlap between anorexia nervosa and ocd. Anorexia nervosa is a life-threatening illness and anyone who may have it needs immediate evaluation.