TUESDAY, Sept. 18 (HealthDay News) -- Getting plenty of aerobic exercise can help overweight children reduce their risk of diabetes, according to a new study.

One-third of U.S. elementary school-aged youngsters are overweight or obese. Childhood obesity is associated with a range of health problems formerly thought to occur only in adults, including type 2 diabetes, according to background information in the study.

Researchers assessed how different amounts of aerobic exercise affected diabetes risk factors, such as insulin resistance, levels of overall body fat and abdominal fat in more than 200 inactive overweight or obese U.S. children. The children had an average age of 9.4 years old.

Some of the children were randomly assigned to low (20 minutes a day) or high (40 minutes a day) amounts of aerobic training five days a week for an average of 13 weeks. They were compared to a control group of children who did their normal physical activity.

The study was published in the Sept. 19 issue of the Journal of the American Medical Association, a theme issue on obesity published to coincide with an Obesity Society meeting.

Children who did low and high amounts of aerobic exercise had greater reductions in insulin resistance than those in the control group, along with greater decreases in overall body fat and abdominal fat, said Catherine Davis, of the Medical College of Georgia, and colleagues, in a journal news release.

The exercise-related reductions in diabetes risk factors occurred in both boys girls, and in children of different races.

More information

The U.S. National Diabetes Education Program outlines how to prevent type 2 diabetes in children.

TUESDAY, Sept. 18 (HealthDay News) -- Obese adults with excess abdominal fat and insulin resistance are more likely to develop diabetes than obese adults without these characteristics, a new study suggests.

The research was published in the Sept. 19 issue of the Journal of the American Medical Association, a theme issue on obesity.

The study included more than 700 obese people, aged 30 to 65, who did not have diabetes or cardiovascular disease at the start of the study. During an average follow-up of seven years, 11.5 percent of the participants developed diabetes, according to a journal news release.

Having excess visceral fat (fat located inside the abdominal cavity, around the internal organs) and insulin resistance was associated with an increased risk for type 2 diabetes. But obese adults with higher amounts of total body fat and subcutaneous fat (underneath the skin) did not have this increased risk, the study found.

In insulin resistance, the body does not use the insulin -- a hormone that helps regulate blood sugar -- properly.

The findings suggest that assessing fat distribution and insulin resistance in obese adults may help identify those at increased risk for developing diabetes, said Dr. James de Lemos, of the University of Texas Southwestern Medical Center in Dallas, and colleagues.

The study uncovered an association between abdominal fat and diabetes risk, but didn't prove the existence of a causal relationship.

The researchers noted that rising rates of overweight and obesity have contributed to a doubling in type 2 diabetes incidence over the past three decades.

More information

The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about type 2 diabetes.

TUESDAY, June 5 (HealthDay News) -- The larger your waist circumference, the greater your risk for type 2 diabetes, a new study has found.

The study examined the association between waist circumference, body-mass index (BMI, a measurement of body fat based on height and weight) and type 2 diabetes.

Both waist circumference and BMI were associated independently with diabetes risk, but waist circumference was a stronger risk factor in women than in men, Claudia Langenberg, of the Institute of Metabolic Science at Addenbrooke's Hospital in Cambridge, England, and colleagues said in a news release from the Public Library of Science.

The findings, published online June 5 in the journal PLoS Medicine, suggest that measuring waist circumference in overweight people could be an effective way to prevent diabetes, because it would identify high-risk people who may benefit from counseling about lifestyle changes, the researchers said.

"Our results clearly show the value that measurement of [waist circumference] may have in identifying which people among the large population of overweight individuals are at highest risk of diabetes," the study authors said.

About one-third of people in the United States and United Kingdom are overweight, Langenberg and colleagues noted in the news release.

Although the study showed an association between larger waist circumference and increased risk of type 2 diabetes, it did not prove a cause-and-effect relationship.

More information

The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about type 2 diabetes.