The report is the latest in a line of alarm calls about the dangerous rise in obesity taking place in the UK and is aimed at government, health professionals, the food industry and the public.
Over half the UK population is currently either overweight or obese - in 2002, 70 per cent of men and 63 per cent of women - and obesity in two- to four-year-old children almost doubled from 5 per cent to 9 per cent from 1989-1998. If current trends continue, conservative estimates are that at least one-third of adults, one fifth of boys and one-third of girls will be obese by 2020.
A cross-governmental task force should be established at Cabinet level to develop national strategies for tackling overweight and obesity, and to oversee the implementation of these strategies, says the report from the Royal College of Physicians, the Faculty of Public Health and the Royal College of Paediatrics and Child Health.
The strategies should include a sustained public education campaign to improve people's understanding of the benefits of healthy eating and active living, and to motivate people to eat a healthier diet. New standards in nutritional content, food labelling, and food marketing and promotion should be agreed jointly by the food industry and the Food Standards Agency and incentives to encourage the production, promotion and sale of healthier foods should also be introduced, argue the medical experts.
They also call for population-wide initiatives at local level to promote healthy eating and increased physical activity in public places, such as schools and hospitals.
Further funded research to improve understanding of the societal and cultural factors behind the epidemic of overweight and obesity, and the development and implementation of effective prevention and treatments is also needed, according to the report, called 'Storing Up Problems: The medical case for a slimmer nation'.
Being overweight restricts body activity, damages health and shortens life; heart disease, stroke, joint problems and the commonest form of diabetes (type 2) are direct effects of obesity and overweight. People of every age, every region and from all population groups are affected, and the report's recommendations apply to all age groups from childhood to old age, and specifically include people at high risk.
Overweight and obesity also result in a huge financial burden for government, the NHS and society as a whole - the National Audit Office estimates costs to the NHS of at least £0.5 billion a year, and £2 billion to the wider economy.
Professor Peter Kopelman, chair of the working party, said: "This report highlights the terrifying health consequences of the obesity epidemic that will particularly impact on our children unless effective and coherent preventive measures are taken. The report identifies responsibilities of every segment of society from central government to individual families, and makes practical and realistic recommendations that need to be taken forward immediately to achieve a slimmer and healthier nation."
Professor Sian Griffiths, president of the Faculty of Public Health, added: "The solution requires partnerships at all levels - across government, who can regulate and create health policies, within communities where engagement in healthier environments (such as schools, workplaces) can encourage individuals in making healthier choices. Obesity is a serious threat to our well-being and we need to get the health balance right, not only through taking individual responsibility but through measures which make it easier to make healthier choices about how we live."