Objective To describe why and how capacity-building systems for scaling up nutrition programmes should be constructed in low- and middle-income countries (LMIC). Design Position paper with task force recommendations based on literature review and joint experience of global nutrition programmes, public health nutrition (PHN) workforce size, organization, and pre-service and in-service training. Setting The review is global but the recommendations are made for LMIC scaling up multisectoral nutrition programmes. Subjects The multitude of PHN workers, be they in the health, agriculture, education, social welfare, or water and sanitation sector, as well as the community workers who ensure outreach and coverage of nutrition-specific and -sensitive interventions. Results Overnutrition and undernutrition problems affect at least half of the global population, especially those in LMIC. Programme guidance exists for undernutrition and overnutrition, and priority for scaling up multisectoral programmes for tackling undernutrition in LMIC is growing. Guidance on how to organize and scale up such programmes is scarce however, and estimates of existing PHN workforce numbers - although poor - suggest they are also inadequate. Pre-service nutrition training for a PHN workforce is mostly clinical and/or food science oriented and in-service nutrition training is largely restricted to infant and young child nutrition. Conclusions Unless increased priority and funding is given to building capacity for scaling up nutrition programmes in LMIC, maternal and child undernutrition rates are likely to remain high and nutrition-related non-communicable diseases to escalate. A hybrid distance learning model for PHN workforce managers' in-service training is urgently needed in LMIC.