To briefly review the current understanding of the aetiology and prevention of chronic diseases using a life course approach, demonstrating the life-long influences on the development of disease.

A computer search of the relevant literature was done using Medline-‘life cycle’ and ‘nutrition’ and reviewing the articles for relevance in addressing the above objective. Articles from references dated before 1990 were followed up separately. A subsequent search using Clio updated the search and extended it by using ‘life cycle’, ‘nutrition’ and ‘noncommunicable disease’ (NCD), and ‘life course’. Several published and unpublished WHO reports were key in developing the background and arguments.

International and national public health and nutrition policy development in light of the global epidemic in chronic diseases, and the continuing nutrition, demographic and epidemiological transitions happening in an increasingly globalized world.

There is a global epidemic of increasing obesity, diabetes and other chronic NCDs, especially in developing and transitional economies, and in the less affluent within these, and in the developed countries. At the same time, there has been an increase in communities and households that have coincident under- and over-nutrition.

The epidemic will continue to increase and is due to a lifetime of exposures and influences. Genetic predisposition plays an unspecified role, and with programming during fetal life for adult disease contributing to an unknown degree. A global rise in obesity levels is contributing to a particular epidemic of type 2 diabetes as well as other NCDs. Prevention will be the most cost-effective and feasible approach for many countries and should involve three mutually reinforcing strategies throughout life, starting in the antenatal period.

To review the evidence on the diet and nutrition causes of obesity and to recommend strategies to reduce obesity prevalence.

The evidence for potential aetiological factors and strategies to reduce obesity prevalence was reviewed, and recommendations for public health action, population nutrition goals and further research were made.

Protective factors against obesity were considered to be: regular physical activity (convincing); a high intake of dietary non-starch polysaccharides (NSP)/fibre (convincing); supportive home and school environments for children (probable); and breastfeeding (probable). Risk factors for obesity were considered to be sedentary lifestyles (convincing); a high intake of energy-dense, micronutrient-poor foods (convincing); heavy marketing of energy-dense foods and fast food outlets (probable); sugar-sweetened soft drinks and fruit juices (probable); adverse social and economic conditions—developed countries, especially in women (probable).

A broad range of strategies were recommended to reduce obesity prevalence including: influencing the food supply to make healthy choices easier; reducing the marketing of energy dense foods and beverages to children; influencing urban environments and transport systems to promote physical activity; developing community-wide programmes in multiple settings; increased communications about healthy eating and physical activity; and improved health services to promote breastfeeding and manage currently overweight or obese people.

The increasing prevalence of obesity is a major health threat in both low- and high income countries. Comprehensive programmes will be needed to turn the epidemic around.

To indicate why the world's most powerful nation state and one powerful sector of the food and drink production and manufacturing industry are determined to demolish the 2004 WHO (World Health Organization) global strategy on diet, physical activity and health, and to disassociate it from the 2003 WHO/FAO (Food and Agriculture Organization) expert report on diet, nutrition and the prevention of chronic diseases, which with its background papers is the immediate scientific basis for the strategy. To encourage representatives of nation states at the 2004 WHO World Health Assembly to support the strategy together with the report, so that the strategy is explicit and quantified, and responds to the need expressed by member states at the 2002 World Health Assembly. This is for an effective global strategy to prevent and control chronic diseases whose prevalence is increased by nutrient-poor food low in vegetables and fruits and high in energy-dense fatty, sugary and/or salty foods and drinks and also by physical inactivity. Of these diseases, obesity, diabetes, cardiovascular diseases and cancers of several sites are now the chief causes of morbidity and mortality in most countries in the world.

A summary of the global strategy and its roots in scientific knowledge accumulated over the last half-century. Reasons why the global strategy and the expert report are opposed by the current US government and the world sugar industry, with some reference to modern historical context. A summary of the trajectory of the global strategy since its first draft made in early 2003, and a further summary of its weaknesses, strengths and potential.

The 2004 WHO global strategy and the 2003 WHO/FAO expert report are perceived by the current US administration as an impediment to US trade and international policy, within a general context of current US government hostility to the UN (United Nations) system as a brake on the exercise of its power as the world's dominant nation. Policy-makers throughout the world should be aware of the contexts of current pressures put on them by powerful nation states and sectors of industry whose ideologies and commercial interests are challenged by international initiatives designed to improve public health and to leave a better legacy for future generations.