The term 'capacity building' is used in the health promotion literature to mean investing in communities, organizations and structures to enhance access to knowledge, skills and resources needed to conduct effective health programs. The Eat Well SA project aimed to increase consumption of healthy food by children, young people and their families in South Australia. The project evaluation demonstrated that awareness about healthy eating among stakeholders across a range of sectors, coalitions and partnerships to promote healthy eating and sustainable programs had been developed. The project achievements were analysed further using a capacity-building framework. This analysis showed that partnership development was a key strategy for success, leading to increased problem-solving capacity among key stakeholders and workers from education, child care, health, transport and food industry sectors. It was also a strategy that required concerted effort and review. New and ongoing programs were initiated and institutionalized within other sectors, notably the child care, vocational education and transport sectors. A model for planning and evaluating nutrition health promotion work is described.