The incidence of food refusal associated with illness is reviewed, not illness by illness, but according to those factors that affect the ability to eat; normal learning about eating, aversive learning about eating, regulation of appetite, children's cognitions about foods, and parental anxiety about intake. Diseases affecting the major organs are likely to generate food refusal based on at least one of these factors, if not all of them. However, some minor disease processes can also have a major impact on food acceptance. Child temperament also affects food acceptance and may interact with the disease process to produce food refusal.