Worldwide, it is estimated that more than 22 million children under five years old are obese or overweight, and more than 17 million of them are in developing countries. Each of these children is at increased risk of developing type 2 diabetes (which used to be known as mature-onset diabetes), say the World Health Organization (WHO) and the International Diabetes Federation (IDF).

Tackling childhood obesity now is a highly effective way of preventing diabetes in the future,” said Dr Catherine Le Gale`s-Camus, WHO Assistant Director-General for Noncommunicable Diseases and Mental Health, in the lead-up to World Diabetes Day on 14 November 2004.

Chronic diseases such as diabetes, heart disease, cancer and stroke are a barrier to economic development. While undernutrition continues to be a key concern, particularly in developing countries, governments are also facing up to the fact that many children in all regions of the world have poor eating habits and are not getting enough exercise.

Globally, an estimated 10% of school-aged children, between five and 17 years old, are overweight or obese, and the situation is getting worse. In the United States, for example, the rate of obesity and overweight among children and adolescents aged 6 to 18 years increased to more than 25% in the 1990s from 15% in the 1970s.

Such increases are not restricted to developed countries. In China, the rate of overweight and obesity observed in a study of urban schoolchildren increased from almost 8% in 1991 to more than 12% six years later. In Brazil, the rate of overweight and obesity among children and adolescents 6 to 18 years old more than tripled from 4% in the mid 1970s to over 13% in 1997. The link between obesity and diabetes is well-established. Around 90% of people with diabetes have type 2 diabetes and of these the vast majority are overweight or obese. “Overweight and obesity increase the risk of many chronic diseases, including type 2 diabetes, heart disease, stroke and some cancers. Unless we address the underlying causes of the obesity epidemic it has the potential to overwhelm health systems throughout the world,” said Dr Le Galès-Camus. “The direct health care costs of diabetes already account for between 2.5% and 15% of annual health care budgets.”

WHO is working with its Member States throughout the world to implement the Global Strategy on Diet, Physical Activity and Health, which was adopted at the May 2004 World Health Assembly.

The strategy recommends a comprehensive range of changes at the individual, community, national and international levels which, if effectively implemented, have the potential to turn around the obesity epidemic. The strategy addresses changes needed in lifestyles that have been linked to the increase in overweight and obese children over the last twenty years.

Increased availability and promotion of foods high in fat and sugar mean that children no longer eat the way their parents did. Nor do they do the same amount of physical activity. In each country the situation is different, but the reasons why children are less active than a generation ago include increased urbanization and mechanization, changes to transport systems and increased hours spent in front of TVs and computers.

Yet small changes can make a big difference. In Singapore, nutrition education in class, combined with a school environment offering healthy foods and drinks, and special attention for students who were already overweight or obese, resulted in a significant decline in the number of obese students. In the UK, limiting access to sweet, fizzy drinks at a group of primary schools resulted in slimmer children. Other studies have demonstrated success by increasing physical activity in school, making changes to school lunches, limiting hours spent watching TV and providing health education.

Professor Pierre Lefèbvre, President of IDF, underlined the need for urgent action. “Children and adolescents who are overweight tend to grow into overweight adults. Poor habits of nutrition and lack of physical activity are likely to endure, putting today’s young people at risk of type 2 diabetes in the future. Even in childhood, overweight and obesity lead to higher levels of blood glucose (sugar), lipid (fat) and blood pressure. In many populations, doctors are seeing increasing numbers of adolescents with type 2 diabetes, a disease that in the past was not normally seen until middle or older age.”

Diabetes is a chronic condition that occurs when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces. People who have type 1 diabetes produce very little or no insulin and require daily injections of insulin to survive. People with type 2 diabetes cannot use insulin effectively. They can sometimes manage their condition with lifestyle measures alone, but oral drugs are often required and, less frequently insulin, in order to achieve good metabolic control. Type 2 diabetes used to be known as non-insulin dependent diabetes or mature onset diabetes.

WHO and IDF are working together to raise awareness about diabetes worldwide. Their joint project, Diabetes Action Now, is supported by a World Diabetes Foundation grant to IDF and by WHO funds.