From Bombay to Beijing, a newly affluent Asian middle class is increasingly adapting Western lifestyles. Many city dwellers opt for high calorie fast food instead of healthier traditional meals and are becoming less and less physically active. This comes with a price: diabetes, mainly caused by excess weight and lack of exercise, has reached epidemic levels in Asia. The disease is growing at a faster pace in Asia than anywhere else in the world and is increasingly affecting younger people. Claudia Blume reports from VOA's Asia News Center in Hong Kong.

Diabetes is fast becoming an Asian disease. The continent is home to four of the world's 10 largest diabetic populations - India, China, Japan and Pakistan. In India alone, more than 35 million people are estimated to have diabetes, more than in any other country in the world.

In percentage terms, the worst affected nation is the tiny Pacific island state of Nauru, where more than 40 percent of the population has the disease.

In a healthy body, thepancreasreleases insulin, which transforms blood sugar into energy. People with diabetes either do not make enough insulin or their bodies do not use the insulin they make, resulting in the build-up of sugar in the bloodstream.

Most patients have type 2 diabetes, which is mainly caused by obesity and lack of exercise. Type one diabetes, often called juvenile diabetes, usually strikes children and young adults, and occurs when the body'simmune systemdestroys insulin-producing cells. Both types can lead to complications such as heart disease, kidney damage and blindness.

Medical textbooks often describe type 2 diabetes as a disease of the middle-aged and the elderly. But Jonathan Shaw, deputy director of the International Diabetes Institute in Australia, says this is changing rapidly. Increasingly, people under 40 are affected, especially in Asia.

"We are now even in European populations, but especially in Asian populations, seeing quite commonly type 2 diabetes in adults in their 20s and 30s and there are now reports of type 2 diabetes in adolescence and even children," said Shaw. "So it's occurring at younger and younger ages. At any given sort of level of risk, it always seems that people of Asian origin will more likely to develop diabetes than people of European origin."

Shaw says there is evidence that some ethnic groups in Asia, particularly some in South Asia, and Pacific Islanders, have a genetic predisposition toward diabetes.

But the main culprit is lifestyle. Affluent Asians are rapidly adopting westernized ways of life, such as high-fat fast food diets and sedentary lifestyles. Ronald Ma, a diabetes specialist at the Prince of Wales hospital in Hong Kong, blames unhealthy habits for the fact that about 10 percent of the city's population has diabetes.

"Sometimes if they have to rush they eat a lot of fast food and unhealthy food - high fat, high salt kind of food," he said. "They rarely have time to exercise, they spend a lot of time in front of the computer, sitting around. The general lifestyle is really as unhealthy as it can get in terms of getting these chronic illnesses like diabetes."

Because of its connection to lifestyle, the disease shows up in Asian cities far more than in the countryside. In India, for example, urban residents are four times more likely to develop diabetes than those living in villages.

Jonathan Shaw says the epidemic is exploding faster in Asia than in any other region.

"For example the Western Pacific region currently has 67 million people with diabetes and we project it will increase by 2025 to 99 million, that's a 48 percent increase," said Shaw. "The Indian sub-continent, including Bangladesh, Pakistan and Sri Lanka as well, we estimate currently has 47 million with diabetes. That will grow to 80 million by the year 2025, almost certainly the growth there is underestimated."

As in the West, most people in Asia with type 2 diabetes are overweight. But experts say many Asian diabetics are less overweight than most Western patients. Their body fat tends to be more often stored around the abdomen, however, which increases the risk of getting the disease.

Diabetes is sometimes called a silent killer because many people do not know they have the disease. Often, there are no symptoms for years. The International Diabetes Institute says awareness of the disease is low in Asia, particularly in less developed countries. Information on how to manage diabetes once it is diagnosed often is hard to come by.

Some of those affected have taken matters into their own hands.

Lily Zhou's husband was diagnosed with diabetes two years ago. When the Beijing resident searched for Chinese-language information on the disease on the Internet, she was disappointed by what she found. Zhou decided to create her own Web site, called Tangzhu, which means "master of glucose".

"The Web site is for information exchange and self-management of the diabetes," she said. "We hope it can be a platform for people with diabetes to share their opinions and work together to have a better life."

Diabetes experts say it is crucial to raise the awareness of governments in the region about the enormous scale of the problem. They point out that many diabetics need drugs every day to stay alive, and that diabetes causes many victims to become disabled or to need extensive hospital treatment, all of which can cut into government budgets.

They say Asian health officials often do not recognize that non-communicable diseases such as diabetes are already as big a threat for developing countries as they are for more developed ones.