Is there a relationship between eating disorders and substance abuse? At least one study, known as "Food for Thought - Substance Abuse and Eating Disorders," shows that up to 50 percent of individuals with an eating disorder also abuse alcohol or illicit drugs, as opposed to nine percent of the general population. On the flip side of this, up to 35 percent of alcohol or illicit drug abusers have eating disorders, while the figure for the general public with eating disorders is only three percent.