We used our experience assisting in the development of and evaluating the Alberta Nutrition Guidelines for Children and Youth (ANGCY) as a basis for exploring roles that registered dietitians (RDs) can play within health promotion, and how others perceive the RD role. Data were generated via 12 key informant interviews and observations during a multiple case study of recreation facilities that had and had not adopted the ANGCY. We also drew on dialogue and personal observations during development of the ANGCY. Dietitians working in government, academia, community settings, private practice, and industry played an important role throughout the development and implementation of the ANGCY. Some sectors proactively sought RD expertise, while others with less ability to pay accessed RDs' services less. Informants generally regarded RDs in a positive light. Findings indicate the profession should incrementally adjust training models to reflect emerging areas of practice, and highlight the need for RDs to proactively seek new avenues in which to apply their skills. These actions will help RDs remain the trusted source of food and nutrition information, not only in health care, but also within health promotion settings.