The Difference between Anorexia Nervosa and Bulimia Nervosa

Dr. David M. Garner is the president of River Center Foundation, a nonprofit committed to advancing research and treatment of eating disorders located in the Toledo, Ohio suburb of Sylvania. Since earning a PhD in clinical psychology from York University in 1975, Dr. David M. Garner has made recognized contributions to the global scientific community through his research on eating disorders, especially anorexia nervosa and bulimia nervosa.

While people with anorexia are often thin and underweight, most people with bulimia maintain an average weight. Even though distinctions between anorexia nervosa and bulimia nervosa have been emphasized in the research literature, it is important to recognize that the different diagnostic subgroups tend to share many features in common. For example, even though anorexia nervosa patients are differentiated into "restricter and "binge eating/ purging subtypes, it must be remembered that most eating disorder patients "restrict their food intake,” and they unduly evaluate their self-worth in terms of weight or shape. Differences between diagnostic groups on psychological variables are generally less remarkable than the extraordinary heterogeneity within each of the diagnostic subgroups in terms of demographic, clinical, and psychological variables. Diagnostic boundaries are fluid since patients have been observed to move between diagnostic categories at different points in time. For example, patients move between the two subtypes of anorexia nervosa (restricting and binge eating/purging types); however, the tendency is for restricters to move toward bulimia (and purging) more often than bulimic anorexics move to an exclusively abstaining. Although extreme weight loss is a defining feature of anorexia nervosa, most bulimia nervosa patients have experienced extreme weight loss as well, they just start at a higher body weight. From a clinical point of view, there is possibly greater heuristic value in directly assessing the psychological domains that are conceptually relevant across all eating-disorder subgroups rather than simply drawing inferences from the DSM-5 diagnostic categories.