In mordern society, nutritional and appetite disorders occur in epidemic proportions and are serious health harzards. Obesity and diabetes affect over 30% of American population, while eating disorders, such as anorexia nervosa and bulimia nervosa occur in a growing number of adolescences and young adults. The changes in various sociocultural aspects with the introduction of Westernized culture have had the effect of increasing the risk of same problems in Korea. Disorderd eating patterns are a primary symptom of numerous psychiatric disorders and loss of appetite and cachexia, during illness or in the elderly, preclude proper medical treatment for restoring good health or preserving life. Increased understanding of the systems of the body and brain, related to energy and nutrient balance, may help us to treatment and ultimately prevent these commom disorders. In this review, the author highlights the psychobiological mechanisms or factors which are associated with eating behavior, especially in the view of intake psychobiology. This review would be concentrated on 1) the theoretical concepts and theories of eating behavior ; 2) the psychobiological determinants of food intake ; and 3) the psychobiological control of eating behavior.