BIOLOGICAL AND PSYCHOLOGICAL CORRELATES OF INTERMITTENT DIETING BEHAVIOR IN YOUNG-WOMEN - A MODEL FOR BULIMIA-NERVOSA

The eating disorder bulimia nervosa is characterized by alternating pe riods of strict dieting and overeating. Patients also report mood fluc tuations, frequent eating related thoughts, fear of loss of control ov er eating, impairment of cognitive abilities such as concentration, an d somatic complaints. The present study attempted to clarify to what e xtent these symptoms are consequences of the dieting behavior. Nine he althy young women, classified as unrestrained eaters, were set on a in termittent dieting schedule over 4 weeks. Four days each week (Tue, We d, Thu, Fri) they had to reduce their intake below 600 kcal/day, the o ther 3 days they could eat without restrictions. Psychological variabl es were assessed by means of a standardized diary. Biological indices of starvation were also measured repeatedly. There was no substantial weight loss after the 4 weeks, although subjects had significantly inc reased levels of betahydroxybutyric acid during the dieting periods, a nd decreased levels of t3 after 2 weeks. The reported tendency to over eat and the actual calorie intake during the days of unlimited access to food showed a significant increase over the 4-week period. Eating-r elated thoughts, feelings of hunger, and fear of loss of control were significantly more frequent during periods of dieting, compared to day s of normal eating. Subjects also reported worse mood, heightened irri tability, difficulties concentrating, and increased fatigue. These res ults suggest that a substantial part of symptoms of bulimic patients m ight be associated with the frequent periods of an extremely restraine d eating behavior.