This case study gives several examples of how theoretical nutrition interventions have been translated into practice. The report identifies successes and failures, problems and solutions, in a variety of nutrition interventions tried by the U.S. Agency for International Development in several different countries. It serves both as a resource for guiding further implementation of the interventions analyzed (i.e., exclusive breastfeeding; integrating family planning into food security; nutrient supplements; nutrient assessment, counseling, and support; and HIV nutrient intervention), and also as a guide for how to assess and evaluate further interventions.