Good Calories, Bad Calories

Throughout this period, Van Itallie’s reviews of dietary therapy for obesity were singularly dedicated to dismissing any evidence that favored the use of carbohydrate-restricted diets. They would invariably begin with the declaration that carbohydrate-restricted diets were just another way to restrict calories, and they would proceed to refute claims made about the diets on the basis that these claims (not to be confused with observations of the diets’ efficacy) had not been established beyond reasonable doubt. By the end of these reviews, Van Itallie would promote the continued treatment of obesity by balanced, calorie-restricted diets, while acknowledging that there was “increasing recognition of [their] ineffectiveness.”^*126 He would reject any suggestion that carbohydrate-restricted diets should be tried instead, while simultaneously acknowledging that these diets were “quite popular and have been followed with varying degrees of success by many dieters.”

George Bray’s influence in removing the fattening carbohydrate and carbohydrate-restricted diets from the nutritional wisdom was more subtle than Van Itallie’s, but may have been ultimately more significant. Bray was a graduate of Harvard Medical School. In the late 1960s, he studied animal models of obesity at UCLA’s Harbor General Hospital in Torrance, California. He also collaborated peripherally with Ethan Sims on his experimental obesity studies (Bray had been a medical-school classmate of Sims’s colleague Ed Horton) and had notable disagreements with Sims about how this research should be interpreted. In 1973, Bray cochaired the NIH’s first obesity conference; he then edited and drafted the subsequent NIH report, Obesity in Perspective. In 1977, he chaired the Second International Congress on Obesity and a second NIH conference on obesity. He then edited the NIH report Obesity in America, which was published in 1979. Meanwhile, he edited or wrote three of the half-dozen textbooks or clinical manuals on obesity that were published in the United States during the decade—Treatment and Management of Obesity (1974), The Obese Patient (1976), and Obesity: Comparative Methods of Weight Control (1980)—which means effectively all of those not edited or written by Stunkard.^†127

Bray believed that all diets worked by restricting calories, and since restricting calories eventually failed, nothing else need be discussed. He dismissed as irrelevant the work of those investigators who did actively study the dietary treatment of obesity, like Charlotte Young, who gave the presentation on dietary therapy at the NIH conference on obesity that Bray organized and chaired in 1973. Young specialized in the study of body composition, and she had been studying diets and obesity at Cornell since 1950. In the official NIH report on the conference, Obesity in Perspective. Bray treated her discussion of carbohydrate-restricted diets as naive and of no consequence. In the book he coedited the year after the conference, Treatment and Management of Obesity, Young’s observations on carbohydrate-restricted diets are described as still requiring further “confirmation before they can be fully accepted…. The question of the value of a low carbohydrate diet and its effectiveness in weight loss is still unresolved.” In The Obese Patient, published three years after the NIH conference, Bray wrote of Young’s studies, “The data are suggestive and require careful replication with larger groups of individuals.” Yet nowhere in the NIH report on the conference, including a lengthy list of research priorities and “gaps in our current knowledge,” did Bray raise the possibility that further research was needed on any dietary therapy for obesity, let alone, as Bray’s own textbooks had suggested, the unresolved question of the value of carbohydrate restriction. Bray then proceeded to become the leading proponent of the hypothesis that obesity, like heart disease, was caused primarily by the dense calories of dietary fat, and thus could be cured or prevented by replacing the fat in the diet with carbohydrates.

The dissociation of the science of fat metabolism from any discussions of the cause or treatment of obesity was particularly conspicuous throughout this era and could be considered its legacy. When Bray, Van Itallie, Cahill, and Hirsch gave review talks at these conferences, as they did throughout this period, they would raise the issue of carbohydrate-restricted diets only to refute the claims that such diets offered a metabolic advantage over low- calorie diets. They would omit any mention of research that might explain the reported efficacy of the diets, even when that research was discussed at the same conferences and by investigators they knew personally. In 1977, for instance, Donald Novin, director of the Brain Research Institute at UCLA, discussed what he called the “carbohydrate hypothesis of ingestive behavior” at Bray’s Second International Congress on Obesity. Novin suggested that the “widespread popularity of the low carbohydrate diets” could be explained by the effect of carbohydrates on insulin, and then of insulin on fat deposition and thus hunger. Bray, who had worked closely with Novin at UCLA, gave the summary talk at the conference on obesity therapies and omitted mention of Novin’s hypothesis.^*128 When M. R. C. Greenwood discussed the effect of insulin on the enzyme lipoprotein lipase, LPL, the “gatekeeper” for fat accumulation in cells, at the Fourth International Congress on Obesity, Hirsch ignored the implications in his review of dietary therapy, even though Greenwood had received her doctoral degree with Hirsch.

In retrospect, the influential figures in the clinical investigation of human obesity in the 1970s can be divided into two groups. There were those who believed carbohydrate-restricted diets were the only efficacious means of weight control—Denis Craddock, Robert Kemp, John Yudkin, Alan Howard, and Ian McLean Baird in England, and Bruce Bistrian and George Blackburn in the U.S.—and wrote books to that effect, or developed variations on these diets with which they could treat patients. These men invariably struggled to maintain credibility. Then there were those who refused to accept that carbohydrate restriction offered anything more than calorie restriction in disguise—Bray, Van Itallie, Cahill, Hirsch, and their fellow club members. These men rarely if ever treated obese patients themselves, and they repeatedly suggested that since no diet worked nothing was to be learned by studying diets.

Bray would routinely equate the carbohydrate-restricted diet to every fad diet that came along—the grapefruit diet, the banana diet, the ice-cream diet. But when he testified before McGovern’s subcommittee in 1977 and described McGovern’s Dietary Goals of a carbohydrate-rich diet for the entire nation as “highly commendable,” he also submitted as part of his testimony a two-hundred-page report by the British Medical Research Council entitled Research on Obesity, apparently ignoring the fact that the report contradicted his own testimony. Published the same year, it referred to carbohydrate restriction as the diet “commonly prescribed by general practitioners” and considered it more effective and certainly more worthy of discussion than the prescription of diets that depended on restricting calories. The report also noted that the best weight-reduction results on record were those reported by Robert Kemp and Denis Craddock, both British practitioners who prescribed carbohydrate-restricted diets to their patients and published their results, Kemp in the medical journals and Craddock in Obesity and Its Management.

When a new diet book was published every few years touting yet another physician’s variation on carbohydrate restriction, it was treated by Bray and his colleagues as the ultimate evidence that the diet itself didn’t work. “If such diets are truly successful,” asked Van Itallie in his AMA denunciation of Atkins, “why then, do they fade into obscurity within a relatively short period of time only to be resurrected some years later in slightly different guise and under new sponsorship. Moreover, despite the claims of universal and painless success for such diets, no nationwide decrease in obesity has been reported.” Of course, the efficacy of the diet could explain the continued popularity of such books. The diet had survived more or less continuously for over a century and had certainly thrived since the end of World War II. That the medical and nutrition establishments refused to take it seriously, and had even taken to advocating carbohydrate-rich diets instead, could explain the continued high prevalence of obesity.

This nihilistic argument became a mantra. “The evergrowing list of diets are an affirmation of the fact that no diet yet described is by itself a solution to the problem of obesity,” Bray said in his 1977 testimony to McGovern’s Senate committee. When Hirsch gave the review talk on obesity treatments at the Fourth International Congress on Obesity in 1981, he said: “The proliferation and seemingly endless concern with diets for the treatment of obesity suggests that this search is more motivated by financial rewards for the promoters rather than by an earnest desire