BOSTON Even a relatively small amount of exercise and a healthy change in diet can delay the development of diabetes in adults, according to a report in ***New England Journal of Medicine***. According to Reuters, earlier research in China and Sweden produced similar findings, but those studies' methods had been questioned. The new test, led by Dr. Jaakko Tuomilehto of the National Public Health Institute in Helsinki, Finland, involved 523 overweight volunteers. The volunteers were asked to strive for five goals: Reduce their weight by at least 5 percent, limit fat in their diet, reduce their saturated fat intake, increase their consumption of fiber, and exercise at least 30 minutes per day. Half of the group was assigned to receive regular, individualized nutrition counseling. Although the average weight loss in the group that received the counseling was less than 10 pounds, "the effect of these changes in lifestyle on the incidence of diabetes was substantial: The risk of diabetes was 58 percent lower in the intervention group," said Drs. Antonio Tataranni and Clifton Bogardus of the U.S. National Institutes of Health, in an editorial in the journal. "Diabetes had not developed in any of the subjects who reached four or five of the goals," the researchers said. Achieving just a few of the goals, such as getting regular exercise, reduced the diabetes risk substantially. Diabetes, a chronic illness with no cure, is a disease in which the body does not produce or use insulin properly. The cause is unknown, but both genetics and environmental factors such as obesity and lack of exercise seem to play a role, according to the American Diabetes Association. Diabetes is the seventh leading cause of death in the United States. The ADA said as many as 15.7 million people, or 5.9 percent of the U.S. population have the disease.