An eating disorder is a psychological condition characterized by an unhealthy relationship with food. Eating disorders should not be confused with healthy dieting or weight maintenance: they are not a lifestyle choice. Eating disorders are biologically-influenced medical illnesses in which an individual will commonly exhibit an obsession with food, body weight, and shape. When a person has an eating disorder, it creates a dangerous situation that can turn fatal if left unaddressed. Serious medical problems can result from a long-term eating disorder that isn’t professionally treated.