There are no known methods to prevent type 1 diabetes . Several clinical trials are currently in progress or being planned.

Research studies have found that lifestyle changes can prevent or delay the onset of type 2 diabetes among high-risk adults. Lifestyle interventions included diet and moderate-intensity physical activity (such as walking for 2 1/2 hours each week).

Weight
Obesity is the single most important risk factor for type 2 diabetes. Between 80% and 90% of people with diabetes are overweight -- that means they weigh at least 20% more than the ideal body weight for their height and build. To figure out if you're overweight, check the chart below then talk to your doctor. A healthy, low-fat diet and regular exercise can help you lose weight gradually and keep it off.

Age
The risk for type 2 diabetes increases with age. Half of all people diagnosed with diabetes are over 55. Although you can't change your age, you can work on other risk factors if you are over 45 years of age.

Family history
Although you can't change your family history either, it is important for you and your doctor to know what "runs in the family." Having 1 relative with diabetes doubles your chances of having it, and having 2 relatives with diabetes quadruples your chances. Tell your doctor if anyone in your family has diabetes.

Race/ethnic background
Some ethnic groups have a higher risk of diabetes than others. You are at greater risk if you belong to one of these groups:

• Native American
• Hispanic American
• African American
• Pacific Islander

Compared with Caucasians, African Americans are twice as likely to have type 2 diabetes, Hispanic Americans are 2 1/2 to 3 times more likely and Native Americans are 5 times more likely.

Exercise
Exercising and maintaining a healthy weight can reduce your risk of diabetes. Any amount of activity is better than none, but try to exercise 4 to 6 times a week for 30 to 60 minutes each time. If you haven't exercised for a while or you have health problems, talk with your doctor before starting an exercise program.

Diet
A diet high in fat, calories and cholesterol increases your risk of diabetes. In addition, a poor diet can lead to obesity (another risk factor for diabetes) and other health problems. A healthy diet is high in fiber and low in fat. Also, remember to watch your portion size -- how much you eat is just as important as what you eat.

Gestational diabetes
Gestational diabetes is a kind of diabetes that happens only during pregnancy. It occurs in about 3% of pregnant women. Although gestational diabetes goes away after pregnancy, about 40% of women who had gestational diabetes are diagnosed with type 2 diabetes within 15 years.

Even if they don't have gestational diabetes, women who give birth to babies weighing 9 pounds or more are more likely to have type 2 diabetes later in life.

Multiple risk factors
The risk of developing type 2 diabetes increases with the number of risk factors you have. If you have 2 or more risk factors, talk to your doctor about how to delay or prevent type 2 diabetes.