A global health transition is currently underway. The burden of non-communicable diseases (NCDs) is increasing rapidly in the developing world, very much as a result of changes in lifestyles. In addition to changes in tobacco use and physical activity, major changes are taking place in diets, contributing greatly to the growing epidemic of NCD. Thus, a huge global public health challenge is how to influence the trends in diet and nutrition for effective global NCD prevention. The health transition took place rapidly in Finland after World War II and mortality from cardiovascular disease (CVD) was exceptionally high. The North Karelia Project was launched in 1972 as a community-based, and later as a national, programme to influence diet and other lifestyles that are crucial in the prevention of CVD. The intervention had a strong theory base and it employed comprehensive strategies. Broad community organisation and the strong participation of people were the key elements. Evaluation has shown how the diet (particularly fat consumption) has changed and how these changes have led to a major reduction in population serum cholesterol and blood pressure levels. It has also shown how ischaemic heart disease mortality in a working-age population has declined by 73% in North Karelia and by 65% in the whole country from 1971 to 1995. Although Finland is an industrialised country, North Karelia was rural, of rather low socio-economic level and with many social problems in the 1970s and 1980s. The project was based on low-cost intervention activities, where people's participation and community organisations played a key role. Comprehensive interventions in the community were eventually supported by national activities--from expert guidelines and media activities to industry collaboration and policy. Similar principles for nutrition intervention programmes could be used in developing countries, obviously tailored to the local conditions. This paper discusses the experiences of the North Karelia Project in the light of needs from the less-industrialised countries and makes some general recommendations.