[Preventing maternal and child malnutrition: the nutrition component of the Mesoamerican Health Initiative 2015].

To describe the regional master plan of nutrition to address maternal and child malnutrition in a 5- year period developed by the Nutrition Technical Group. The Nutrition Technical Group developed a situation analysis describing the main nutrition problems, policies and programs in Mesoamerica. The situation analysis and a literature review about effective interventions to address malnutrition were conducted to develop a nutrition master plan. The Nutrition Technical Group held various meetings to develop, discuss and validate the master plan. Theory of change identified problems and barriers, the actions to be developed, the changes and impacts expected. A package of interventions is proposed to reduce undernutrition and micronutrient deficiencies useful under different epidemiological contexts. The nutrition master plan provides a guideline of best practices that can be used for evidence-informed decision making and the development of national policies and programs to reduce malnutrition.