Eating behavior among women with anorexia nervosa

Disturbances in eating behavior are defining features of eating disorders. Patients with anorexia nervosa (AN) severely restrict dietary intake, whereas patients with bulimia nervosa (BN) experience recurrent episodes of binge eating.

Although disturbed eating is a hallmark of patients with eating disorders, relatively few objective laboratory studies of eating behavior among persons with eating disorders have been conducted. The current study was designed to measure total consumption during a laboratory test meal of patients with AN at low weight and after weight restoration in comparison to control subjects. In addition, the study aimed to examine the relation between eating behavior and self-reported clinical characteristics, such as restraint over eating, and the relation between changes in these measures during treatment. Finally, the study aimed to examine the relation between changes in psychological symptoms, measured by interview and self-report, and changes in test meal intake during the course of inpatient hospitalization for patients with AN.

Twelve women with AN participated in the study. Six participants were diagnosed with AN, restricting subtype (AN-R), and 4 participants were diagnosed with AN, binge-purge subtype (AN-B/P), by the Structured Clinical Interview for DSM-IV (SCID-IV). All patients participated in a test meal session shortly after admission to the hospital. Eleven of 12 patients were retested after weight restoration, which was defined as attaining equal to 90% of ideal body weight. The second test meal occurred at a mean of 54.18 [+ or -]14.48 d (range: 37.0 d to 84.0 d) after initial testing and a mean of 14.55[+ or -] 6.52 d (range: 6.0 d to 31.0 d) after patients reaches 90% ideal body weight (IBW). All patients were between the ages of 18 y and 45 y and were receiving treatment on an inpatient unit at the New York State Psychiatric Institute at Columbia University Medical Center (New York City). Twelve women without eating disorder symptoms served as the control group. Control subjects were required to be between 90% and 120% IBW.

Patients and control subjects consumed a standardized breakfast on the morning of the test meal. Participants did not consume any additional food or liquid, other than water, before reporting to the laboratory for the meal session 4 h later. The test meal was a strawberry yogurt shake; this test meal was used previously in other eating behavior studies. A shake (approximately 1014 kcal) was provided to participants in a covered, opaque, 83-fluid-ounce container with a straw. The instructions specified that participants should consume as much of the shake as they would like and that the meal would serve as their lunch for the day. The instructions asked participants to avoid touching or manipulating the container in any way. The meal was placed on a modified version of an eating monitor, which measured intake (in g) every 5 s. During the meal, participants were observed through a closed-circuit video monitor.

Participants were asked to make ratings before and after the test meal of hunger, fullness, sickness, loss of control, urge to eat, preoccupation with thoughts of food, and fear of fatness on 15 cm visual analog scales (VAS). Patients with AN were also asked whether they intended to eat less than, as much as, or more than the amount they were expected to eat for lunch on the inpatient unit. At the conclusion of the meal, patients with AN chose whether they believed they had eaten less than, as much as, or more than they typically ate for lunch on the unit, and they used a VAS to rate the difficulty of stopping eating, hunger, fullness, sickness, loss of control, urge to eat, preoccupation with thoughts of food, and fear of fatness.

This study found that patients hospitalized for AN consumed substantially less of a single-item test meal than did control subjects, both before and after weight gain. The considerable changes in weight and in psychological and eating-disordered symptoms that occurred during hospital treatment were not paralleled by changes of similar magnitude in food consumption during the test meal. This finding suggests that, immediately after restoration to a normal weight, many patients with AN exhibit a persistent behavioral eating disturbance that may increase vulnerability to relapse.

R. Sysko, B. Walsh, J. Schebendach, G. Wilson. Eating behavior among women with anorexia nervosa. AJCN; 82(2):296-301 (August 2005) [Correspondence: R. Sysko, Rutgers University Eating Disorders Clinic,