Good Calories, Bad Calories

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.