Good Calories, Bad Calories

In 1941, when Bauer turned to the question of which biological factors might determine or regulate this lipophilia, the understanding of the function of hormones and enzymes in regulating metabolism was still in its infancy. Bauer based his understanding, as Astwood would twenty years later, largely on clinical observations. Local factors in the adipose tissue itself have to be involved, he thought. How else to explain the lipophilic skin graft? Surely something attached to the skin and the adipose tissue determines how much fat it will hold. Hormonal factors have to be involved. Male sex hormones seem to inhibit the kind of fat formation typically seen in women—men who are castrated or whose testicles are destroyed by disease often develop a fat distribution that is more typically feminine. This type of fat distribution, Bauer wrote, is also present in “obese boys in whom the physiologic production of the testicular hormone is not yet sufficient to prevent the accumulation of adipose tissue of the female type. The larger the quantity of fat deposited, the more striking is the resemblance to the female type….” Female sex hormones do not appear to play a major role in determining where fat appears on the body—women who have their ovaries removed put on fat very much like other women. These hormones do, however, seem to affect the quantity of fat, which would explain the tendency of women to gain weight after menopause. Bauer also suggested that insulin plays a role, by enhancing the deposition of glucose in the adipose tissue, a phenomenon first demonstrated in the 1920s, and by increasing the general affinity of the adipose tissue for accumulating fat. The nervous system plays a role as well, Bauer said: researchers had demonstrated that they could increase the amount of fat in fat deposits by severing the nerve fibers that run to the relevant tissue.

Through the 1920s, discussions of the lipophilia hypothesis were confined to the German and Austrian research communities. The relevant research appeared almost exclusively in the German medical literature. Clinicians in the United States began to take notice only in 1933, after Eugene Du Bois convinced Erich Grafe, director of the Clinic of Medicine and Neurology at the University of Würzburg in Germany, that the American medical community could benefit from an English translation of Grafe’s textbook, Metabolic Diseases and Their Treatment. By that time, as Hugo Rony noted, the hypothesis was “more or less fully accepted” in Europe. “It seems to me this conception deserves attentive consideration,” Russell Wilder of the Mayo Clinic wrote in 1938. “The effect after meals of withdrawing from the circulation even a little more fat than usual might well account both for the delayed sense of satiety and for the frequently abnormal taste for carbohydrate encountered in obese persons…. A slight tendency in this direction would have a profound effect in the course of time.”

Knowledge and research on the hypothesis, though, remained largely confined to the German and Austrian research community. When this school of research evaporated with the rise of Hitler and World War II, the notion of lipophilia evaporated with it. Anti-German sentiments in the postwar era may have contributed as well to the disappearance.^*106 In 1955, the year Bergmann died, the primary German textbook on endocrinology and internal medicine included a lengthy discussion of the lipophilia hypothesis in its chapter on obesity, but it was never translated into English. By that time, English had become the international language of science, and the belief that researchers had at least to read German to keep up with the latest advances no longer held sway. (This disappearance of the German and Austrian influence on obesity research is conspicuous in the literature itself. In Rony’s Obesity and Leanness, published in 1940, 191 of 587 references are from German publications; in the 1949 manual Obesity…, written by the Mayo Clinic physicians Edward Rynearson and Clifford Gastineau, only thirteen of 422 references are from the German literature, compared with a dozen from Louis Newburgh alone. By the 1970s, when George Bray, John Garrow, and Albert Stunkard wrote and edited the next generation of obesity textbooks and clinical manuals, this German research was treated as ancient history and entirely absent.)