Self-starvation, with concomitant weight loss, may serve as a dysfunctional behavior to attenuate negative affective states in anorexia nervosa (AN). A total of 91 participants composed of patients with acute AN, women recovered from AN, clinical controls with either depression or anxiety disorder, and healthy controls were tested on a measure of emotion regulation. Patients with acute AN as well as recovered patients with AN and clinical controls showed increased emotion regulation difficulties as compared with healthy controls. In patients with acute AN, a specific association between body weight and emotion regulation was found: the lower the body mass index in patients with acute AN, the lesser were their difficulties in emotion regulation. This association could only be found in the subsample of patients with acute AN but not in the control groups. Moreover, there were no confounding effects of depression or duration of illness. The findings are consistent with the hypothesis that self-starvation with accompanying low body weight serves as a dysfunctional behavior to regulate aversive emotions in AN.