That obese people overeat, at least during periods of weight increase, Bruch said, had been “adequately established.” What she disagreed with was what had now become, thanks in good part to her own research, the conventional interpretation of this observation: that overeating is the cause of obesity, and that the logical treatment is underfeeding. “In the course of my observations,” she noted, “studying many obese people in great detail and following them over a long period of time, I have come to the conclusion that…overeating, though it is observed with great regularity, is not the cause of obesity; it is a symptom of an underlying disturbance…. Food, of course, is essential for obesity—but so is it for the maintenance of life in general. The need for overeating and the changes in weight regulation and fat storage are the essential disturbances.”

In 1973, when Bruch published Eating Disorders: Obesity, Anorexia Nervosa, and the Person Within, she was still struggling with this conflict between psychological and physiological factors in the development of obesity. She acknowledged the need to prescribe reducing diets, and much of her analysis focused on those interpersonal and familial relationships that might contribute to obesity and dietary failure. Yet, she could not escape the suspicion, implied by a growing body of research, that the cause of obesity is a “primary metabolic or enzymatic disorder.” And she acknowledged that it was still up to researchers to unambiguously identify the nature of the disorder. “Studies of human obesity,” she wrote, “are not yet able to differentiate between factors that are the cause of obesity, or the result of it.”

Chapter 17

Chapter Seventeen

CONSERVATION OF ENERGY

The complicated mechanism of the body must be taken into consideration, and the ways it takes to reach its goals are not always the straight paths envisioned in our calculations.

MAX RUBNER, The Laws of Energy Conservation in Nutrition, 1902

BEFORE WORLD WAR II, the proposition that obesity was caused by overeating—the positive-caloric-balance hypothesis—was one of several competing hypotheses to explain the condition. After Hilde Bruch reported that obese children ate immoderately, and Louis Newburgh insisted that a perverted appetite was the fundamental cause of obesity, the positive-caloric-balance hypothesis became the conventional wisdom, and the treatment of obesity, as Jean Mayer observed, became the provenance of psychiatrists, psychologists, and moralists whose primary goal was to rectify our dietary misbehavior. Any attempt to dispute the accepted wisdom was treated, as it still is, as an attempt to absolve the obese and overweight of the necessity to exercise and restrain their appetites, or to sell something, and often both.