Improving results for nutrition: a commentary on an agenda and the need for implementation research.

Research and implementation often exist in separate worlds. To improve results for nutrition, the nutrition research community needs to go beyond "what" works to understand "how" it works. If they do not, nutrition research risks becoming irrelevant to the needs of those who actually make policies and implement programs. Researchers must prioritize research on effectiveness of policies and programs. They should incorporate knowledge and tools of social sciences, including economics, sociology, political science, and management into their work. They should pay greater attention to environmental and institutional variables and understand change strategies, knowledge utilization, and policy processes. Fundamentally, research on implementation should use a systematic approach to produce generalizable evidence and conceptual models, tools, and methods that are communicated effectively to policymakers and programmers. Nutrition researchers need not expand far beyond their disciplinary comfort zone to do this, but they do need to build bridges with other fields to have greater success in addressing nutritional challenges.