Lack of appetite and nutritional difficulties such as food selection and food phobia are common health problems in childhood, especially in infants and young children. Under each nutritional behavior, there can be important physiological causes as well as psychological reasons. The primary aim of treatment is to determine the underlying causes of loss of appetite and other nutritional problems. In the presence of an underlying organic cause, priority treatment should be elimination of this cause. One of the other important approaches is the identification of nutritional problems. This situation is important for the effectiveness of treatment approaches. Nutritional principles appropriate for the age of the child or baby may support the effective treatment of nutritional problems in practice. Determination of the nutritional strength of the patient and the planning of treatment methods for it are important for the effectiveness of the treatment.