In a comprehensive dossier revealing how the global obesity epidemic is affecting children, the IOTF said that one in 10 children is overweight, a total of 155 million. Around 30-45 million within that figure are classified as obese - accounting for 2-3 per cent of the world's children aged 5-17. A further 22 million younger children are also affected, according to previous IOTF global estimates based on WHO data for under fives.
The report, Obesity in children and young people: A crisis in public health, was delivered to the World Health Organisation this week on the eve of a critical decision by government ministers in Geneva on adopting a global strategy on diet, activity and health, and warned that childhood obesity was "increasing in both developed and developing countries," with significantly increased risks that children may develop type 2 diabetes, heart disease and a variety of other co-morbidities.
The high profile of the 'obesity epidemic' in the US has perhaps overshadowed the worrying trend towards obesity in developing countries, the IOTF said. In South Africa, for example, some 25 per cent of girls in the 13-19 year age range were found to be overweight or obese, similar to the US average, using IOTF criteria. However, the figure for boys in South Africa was lower at 7 per cent.
While in some developing countries childhood obesity was most dominant in wealthier social groups, it is also rising among the urban poor "possibly due to their exposure to westernised diets coinciding with a history of undernutrition", the report suggests. Children in lower-income families in developed countries are particularly vulnerable because of poor diet and limited opportunities for physical activity. In the US, for example, overweight rose twice as fast in Hispanic and African-American pre-teenage children compared to white children during the 1990s.
Much of the media focus in Europe has centred on the UK market, with its well-documented penchant for snacking and fast food, but the IOTF's report suggests that the problem is in fact worse in southern Europe, despite the widespread belief that the Mediterranean lifestyle and diet is intrinsically healthier.
According to the IOTF, in northern Europe, an overweight prevalence of 10-20 per cent was found for children, while in southern Europe the prevalence was 20-35 per cent. Recent surveys found that 36 per cent of 9-year-olds in mainland Italy and Sicily were overweight or obese, while in Greece the prevalence was 26 per cent in boys and 19 per cent in girls aged 6-17 years. In Spain, 27 per cent of children and adolescents were affected while in Crete 39 per cent of children aged 12 were found to be overweight.
By way of comparison, in the UK the figure reached 20 per cent of children in 1998 using the IOTF's strict reference assessment methods.
The report was prepared by a special IOTF childhood obesity working group chaired by Professors Ricardo Uauy and Louise Baur, and co-ordinated by Dr Tim Lobstein with the help of expert groups including the Federation of International Societies for Paediatric Gastroenterology, Hepatology and Nutrition (FISPGHAN) and backed by the International Paediatrics Association (IPA).
It identifies a number of factors which have influenced the rising levels of obesity among children, including such diverse issues as an increase in the use of motorised transport when going to and from school, a reduction in the opportunities for recreational physical activity, the growth in the number of TV channels, the rising levels of promotion and marketing of energy-dense foods and larger portion sizes.
The report concludes that the domination of 'obesogenic' or obesity-promoting environmental factors means that treatment is unlikely to succeed without strategies to deal only with the prevailing environment through a broad-based, public health programme, and urges policy-makers to develop strong policies to stem the rising problem.
"It must be concluded that interventions at the family or school level will need to be matched by changes in the social and cultural context so that the bene?ts can be sustained and enhanced," the report states. "Such prevention strategies will require a co-ordinated effort between the medical community, health administrators, teachers, parents, food producers and processors, retailers and caterers, advertisers and the media, recreation and sport planners, urban architects, city planners, politicians and legislators."
Calling on the WHO to help countries to develop National Obesity Action Plans with a high priority set for tackling the prevention of childhood obesity, the report highlights a number of key areas where action is needed. These include improving food labelling information, encouraging food companies to provide more nutritious foods marketed for children, developing criteria for advertising that promotes healthier eating and designing secure play facilities and safe local neighbourhoods.
Co-chair Prof Louise Baur, who is based at University of Sydney Department of Paediatrics and Child Health, in Australia, commented: "Almost daily we receive new reports of the impact of type 2 diabetes affecting younger and younger children because of obesity. That alone should make it imperative that all nations take urgent action to address the key issues affecting the growth of obesity."
Prof Ricardo Uauy, from Chile, chair of public health at the London School of Hygiene and Tropical Medicine, added: "This report is the result of one of the most comprehensive collaborations between experts in the paediatric field, all seriously concerned about what is happening to children throughout the world. We really cannot afford delay any longer. We need to address this challenge with an effective global strategy on diet, activity and health. We must act quickly. The world's children deserve no less."