To the Editor: Shaw and Chisholm described the increasing prevalence of type 2 diabetes in Australia.1 A similar alarming trend exists in China — there will be nearly 1 million new cases of diabetes per year in the 21st century,2 and a total of 290 million people with diabetes by 2010.3

The main risk factor for the development of diabetes in China is obesity. The Chinese are getting fatter.4 As China becomes modernised, people are eating more and exercising less. That eating a healthy diet and becoming physically more active can prevent diabetes is convincingly proven by China’s Daqing IGT (impaired glucose tolerance) and Diabetes Study.5 A total of 577 subjects with IGT were randomised by clinic to either a control group or to one of three active treatment groups: diet only, exercise only, or diet plus exercise. This is the first randomised controlled clinical trial to demonstrate that weight reduction by diet and exercise can significantly reduce the incidence of diabetes in subjects with impaired glucose tolerance.