In the media coverage that followed, those investigators skeptical of the underlying science seemed to have vanished from the public debate. New on the scene were public-interest groups—most notably, the Center for Science in the Public Interest and its director, Michael Jacobson—arguing that neither the NAS nor the surgeon general had gone far enough in pushing a national low-fat diet plan. Both the Washington Post and the New York Times quoted Jacobson scolding the authors of Diet and Health for lacking “the courage” to tell Americans straight out that a healthy lifestyle required much “greater reductions” in total fat, saturated fat, and cholesterol. In the Post article, Arno Motulsky, chairman of the NAS committee that compiled the report, acknowledged that one intention of Diet and Health was to convince Americans further of the existence of a scientific consensus on the benefits of reducing fat in the diet. “Many people may be confused by the vast amount of advice about what to eat,” he said. “Some may have delayed making changes in their diets until they are more convinced that scientists have reached consensus. We hope our report will help these individuals move from inaction and complacency to action.” The public face of the controversy had now shifted entirely. It was no longer about the validity of the underlying science, which was no less ambiguous than ever, but about whether Americans should be eating low-fat diets or very low-fat diets.

One striking fact about this evolution is that the low-fat diets now being recommended for the entire nation had only been tested twice, as I’ve said, once in Hungary and once in Britain, and in only a few hundred middle-aged men who had already suffered heart attacks. The results of those trials had been contradictory. The diets tested since then had been exclusively cholesterol-lowering diets that replaced saturated fats with unsaturated fats.