A change in lifestyle following rapid economic growth is partly to blame
China faces a diabetes epidemic, with almost one in 10 adults having the disease while most cases remain undiagnosed, researchers have said.
Tests showed diabetes was more endemic than previously thought, according to the New England Journal of Medicine.
The figures suggest China has some 90 million diabetics, far more than India.
Rapid economic growth has affected public health, through urbanisation, changed diets and more sedentary lifestyles, researchers said.
Rigorous new tests suggested that more than 92 million Chinese adults had diabetes and that nearly 150 million more were showing early symptoms, researchers said.
This represents a major public health problem for the authorities in Beijing as diabetes is a major factor in illnesses such as heart disease, stroke and kidney disease, correspondents say.
"In the last 10 years, with the country's economy expanding quickly and people's standard of living improving, people's lifestyles have changed," said Yang Wenying, one of the report's 20 authors, who is head of endocrinology at Beijing's China-Japan Friendship Hospital.
"China's economic development has gone from a situation of not being able to eat enough, of poverty, to having enough food and warm clothes, and doing much less exercise," she told the AFP news agency.
The US has a similar percentage of sufferers, but China with its massive population now has more diabetics than anywhere else in the world, says the BBC's Michael Bristow in Beijing.
The Chinese study was based on a representative sample of more than 46,000 adults aged 20 years or older from 14 provinces and municipalities.
Last year, US research suggested that diabetes was becoming a global problem, with more than 60% of all cases likely to occur in Asia.