For decades, public health advocates have confronted industry over dietary policy, their debates focusing on how to address evidentiary uncertainty. In 1977, enough consensus existed among epidemiologists that the Senate Select Committee on Nutrition and Human Need used the diet-heart association to perform an extraordinary act: advocate dietary goals for a healthier diet. During its hearings, the meat industry tested that consensus. In one year, the committee produced two editions of its Dietary Goals for the United States, the second containing a conciliatory statement about coronary heart disease and meat consumption. Critics have characterized the revision as a surrender to special interests. But the senators faced issues for which they were professionally unprepared: conflicts within science over the interpretation of data and notions of proof. Ultimately, it was lack of scientific consensus on these factors, not simply political acquiescence, that allowed special interests to secure changes in the guidelines.