Enormous progress has been made in the past 100 years in improving diet and nutritional status. However, the job is not done. This paper summarizes some of the current challenges and proposes priorities for future research and policy development. The nutrition agenda is more complex than it was 100 years ago. The world now faces undernutrition side-by-side with dietary excess and related chronic diseases. The complexity of modern nutrition necessitates using a systems approach to identifying effective policies and programs. There is a renewed interest in addressing the new nutrition agenda.