Diet, nutritional status and lifestyle practices are significant determinants of the risk of certain cancers. In 1997 The World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) developed a series of evidence-based recommendations to help reduce the population and individual risk of cancer. However, guidance for evaluating concordance or compliance with these recommendations is limited. To illustrate the challenges in evaluation, four publications were reviewed that explored the task of creating operative criteria from which to assess concordance with the tenets of the WCRF/AICR recommendations. Three documents dealt with secondary analysis, whereas one was a prospective inquiry, with procedures and instruments designed to obtain responses to WCRF/AICR cancer-prevention specification. One considered only population-goal criteria, and two dealt implicitly or explicitly with criteria at both population and individual levels. The assessment approaches used by the authors were compared with alternative semantic and conceptual interpretations of the WCRF/AICR population goals and individual guidelines. Attempts to develop operative criteria for assessment of concordance (reflecting either a more superficial or more in-depth parsing of recommendations) have been inconsistent. The results indicate that the language of the WCRF/AICR leaves a certain degree of semantic ambiguity for evaluation purposes. Future design of prospective studies for analyses of behaviours and relevant exposures (including those reported in the 2007 WCRF/AICR report) should carefully consider evaluation criteria and fully document detailed methodology.