A serious health threat is hanging over Asia, putting hundreds of millions of lives at risk. It's not swine flu, nor dengue fever, nor any other infectious disease. It's much deadlier than epidemics of those but it gets much less attention because its effects are only felt in the long term.
Malnutrition - both under- and over-nutrition - is pushing a quarter of the region's population into the arms of early death. In the Asia-Pacific region alone, 578 million people are undernourished, World Health Organisation figures show. In India, half of all children under five have stunted growth, and in mainland China, three out of 10 pregnant women are anaemic.
Unlike many developed regions, Asia bears a double burden - undernourishment and obesity at the same time.
In countries such as India and China, with rapidly growing economies, more people are becoming obese and developing associated lifestyle problems, even as millions go hungry. About 10 per cent of the Chinese population have diabetes and more than 40 per cent of men have high blood pressure, according to WHO figures on non-communicable diseases for last year.
It is not just our physical health that is suffering. According to World Bank estimates, reduced productivity caused by malnutrition shaves 3 per cent off global gross domestic product each year.
Even if people are not starving, malnutrition leaves them more prone to illness, according to Dr Francesco Branca, director of the WHO's department of nutrition for health and development.
'About 10 per cent of non-communicable diseases are due to malnutrition. If we can prevent malnutrition, we can prevent a lot of deaths, especially among young children.'
With that goal in mind, the WHO hosted a three-day meeting of health professionals and representatives from 16 regional countries in Colombo, Sri Lanka, last week to boost efforts to improve nutrition.
Branca says a lack of attention to nutrition exists even within the health care sector in many countries, and governments are not investing enough to deal with the issue.
'Countries are only investing one-tenth of what is required in food and nutrition. But in order to protect the world's entire population from the threat of malnutrition, at least US$10 billion should be invested.
'China is going through a major transition. More people are dying of stroke, heart disease and hypertension. In fact, all these could be tackled through simple dietary changes.'
At the same time, many people in rural areas are poorly fed and underweight. They are caught in a vicious cycle: malnutrition impairs intellectual development, which in turn makes it more difficult for victims to lift themselves out of the poverty trap.
'People with adequate nutrition are more productive and can create opportunities to gradually break the cycles of poverty and hunger,' said the WHO's regional director for the western Pacific, Dr Shin Young-soo.
The number of people who are underweight is a serious problem in South and Southeast Asia. In Laos, more than 30 per cent of young children are underweight; in India, Bangladesh and East Timor, the percentage is more than 45.
The dietary habits of Asians contribute to the problem, says the WHO's regional adviser on nutrition in the western Pacific, Dr Luca Tommaso Cavalli-Sforza. More than 70 per cent of Asians do not eat enough vegetables and fruit, resulting in a lack of vitamins and minerals, he says. Worldwide, between 250,000 and 500,000 children go blind every year because of a lack of vitamin A, and half of them die within a year of losing their sight.
Pregnant women also lack iron and folic acid, essential nutrients for the growth of unborn babies.
Branca says providing iron supplements to Asian women would prevent about 180,000 maternal deaths a year.
Experts are unanimous in their fears for the health of Asian populations as countries become richer and their citizens better fed. With growing affluence, the content of meals tends to become fattier and sweeter, Branca says. While citizens of developing countries ate only 10 kilograms of meat per person per year in the 1960s, the figure climbed to 26kg in the 1990s. It is estimated that by 2030, that figure will have risen to 37kg.
By comparison, in 2002 Americans ate 125kg of meat per person per year.
Branca said the proportion of fat in meals in developing countries had also jumped from 20 to 40 per cent in the past decade - and 'as Asians become better fed with meat ... fruit and vegetable production has not been growing sufficiently'.
Cavalli-Sforza says the growing popularity of Western-style fast food is also damaging the Asian diet. Fast-food chains aim strong marketing campaigns at children, such as by offering free gifts, which encourages people to develop unhealthy eating habits from a young age, he says.
Experts warn that while food is becoming more affordable for those in Asia whose affluence is rising, the gap between the rich and poor is growing. The prices of basic foodstuffs, such as rice and wheat, is constantly rising because of climate change and growing demand, says Dr Brian Thompson of the United Nations' nutrition and consumer protection division - so much so that 'sometimes even the farmers cannot feed themselves properly'.
Representatives from Thailand and Malaysia told the meeting their countries would use taxes on tobacco and alcohol to fund health programmes. One would train volunteers to monitor the condition of high-risk pregnant women, to prevent hereditary diseases and the delivery of babies with low birth weights.
A delegate from China, Dr Xu Zongyu, deputy director of the Department of Maternal Child Health and Community Health, told of a new programme with the Women's Federation targeting anaemia prevention among children aged six months to 36 months in the nation's 592 poorest counties.
He also cited a national programme to provide folic-acid supplements to children in rural areas to prevent brain defects.
Cavalli-Sforza called on governments to order food manufacturers gradually to reduce the content of salt in their products. 'If the salt content is decreased by 20 per cent all of a sudden, it might be difficult for consumers to get used to it. So factories can decrease the use of salt by 5 per cent annually.'
Thompson said villagers in rural areas should be encouraged to set up backyard fish ponds and grow fruit in their gardens to give them easy access to better nutrition. Financial incentives could be offered.
He said special programmes needed to target women. 'If women are poorly fed, how can they bear healthy children? It is a vicious cycle, with Asian children at a disadvantage from birth,' he said.