This report deals with certain theoretical and clinical aspects of the problem of overeating and obesity. It considers the advantages, especially in psychiatric research, if obesity were found to represent, not one disease, but the end stage of a variety of different conditions with differing etiologies. Experimentally-induced obesity in animals serves as a model of such a contingency since it can be produced by different methods, which result in different types of obesity. Some of the most striking differences have been found in the field of behavior, a recent study having demonstrated characteristic differences between the feeding patterns of obese and non-obese mice, and even between the feeding patterns of mice afflicted with different forms of obesity.
The eating behavior of obese human subjects is considered from this point of view, and three distinctive eating patterns are described. The first of these patterns is that of the night-eating syndrome, characterized by morning anorexia, evening hyperphagia, and insomnia. The second pattern is that of the eating binge, in which large amounts of food are consumed in an orgiastic manner at irregular intervals. The third pattern is that of eating-without-satiation which has been observed in persons suffering from damage to the central nervous system.