Although only 15 per cent of Chinese were overweight and 2.6 per cent obese in 2002, well behind the levels of developed countries, the rate at which obesity is increasing is 'alarming', according to Yangfeng Wu, a professor at the Chinese Academy of Medical Sciences and responsible for the country's obesity control programme. "Although the prevalence of obesity in China is relatively low compared with Western countries such as the United States, where over half of adults are either overweight or obese, it is the rapid increase of the condition,4 especially among children, that is particularly alarming," he writes in the current issue of the British Medical Journal. Data from China's national surveys on health in school children showed that the prevalence of overweight and obesity in children aged 7-18 years increased 28 times and obesity increased four times between 1985 and 2000, particularly in boys. The figures suggest that China is fast catching up with the West in terms of its obesity levels, setting itself up for a major public health challenge with rising chronic diseases like heart disease and cancer. Wu says that the government should do more to educate the population about the risks of obesity before it is too late. "The government should develop a better policy for the prevention and control of chronic disease, addressing obesity as one of the key risk factors," he told AP-Foodtechnology.com. "It should use the lessons from the US. They didn't realize how important obesity was as a risk factor for disease but we can learn from them and start to think about how to halt this major risk factor," he added. The rise in obesity in China is a result of major lifestyle changes as higher incomes are spent on processed foods and surging numbers of urbanized populations expend less energy on physical activities. The number of people owning cars has soared in recent years, from 6 million in 2000 to 20 million now, replacing use of bicycles for transport. Also, energy intake from animal sources has increased from 8 per cent in 1982 to 25 per cent in 2002, and the average energy intake from dietary fat among urban Chinese increased from 25 per cent to 35 per cent, above the upper limit of 30 per cent recommended by the WHO. "The obesity epidemic in China may also have its roots in the prevailing social attitudes towards body fatness," writes Wu in the BMJ article. "In Chinese culture, there is still a widespread belief that excess body fat represents health and prosperity. This is perhaps a consequence of China's recent history, where famine and chronic malnutrition caused the deaths of millions of people in the 1950s."Wu said the government was unlikely to take measures that have been proposed in other countries such as subsidizing healthy foods or taxing fatty products. But if enough experts stress the dangers of obesity, it could increase its health education programmes and develop specific policies for the food and agriculture sectors. "The food industry - and especially healthy food providers - have a big role to play and a potentially big market," he added. Further, estimates about risks of obesity for Chinese people appear to have been underestimated. Increasing evidence suggests that standard definitions of overweight based on a body mass index of 25 need to be revised when applied in Asia. "In China, people don't need to be as fat as Americans to develop serious syndromes," explained Wu. This led the government to use lower cut-off points in its guidelines on obesity, with a BMI of 24.0 to 27.9 as overweight, and 28.0 and above as obese. Using these cut points rather than the WHO definitions would increase the prevalence of overweight and obesity in China by a further 66 million, to over a quarter of a billion people.