The trick is to get a blood glucose test every three years starting at age 45—or earlier and more frequently for anyone who's overweight and has any of these additional risk factors: high blood pressure, low HDL (good) cholesterol and/or high triglycerides, polycystic ovarian syndrome (a hormone imbalance that can cause infertility and is associated with insulin resistance), or parents or siblings with diabetes. Risk factors also include being of African-American, Hispanic, Native American, Asian, or Pacific Islander descent; having gestational diabetes or delivering an overweight baby; and not getting enough physical activity. In families with a strong history of the disease, testing should begin when overweight kids are in their teens, says endocrinologist Anne Peters, MD, a diabetes specialist and professor at the University of Southern California's Keck School of Medicine. No matter what your age, if you notice excessive thirst, frequent urination, extreme and persistent hunger, or unexplained weight loss despite overeating, get your blood glucose measured: You may already be diabetic. Other symptoms include fatigue, recurrent yeast infections, slow-healing sores, and blurry vision.
If your blood sugar indicates that you're headed for diabetes, there's a lot you can do. In a two- to five-year study, prediabetics who exercised at moderate intensity for 30 minutes five times a week and dropped, on average, 5 to 7 percent of their body weight with a low-fat, reduced-calorie diet cut their risk of the disease by 58 percent. This approach was nearly twice as effective as taking medication, which mainly helped participants who were younger than 45 and extremely obese. Eating 500 fewer calories a day should be enough to knock off the necessary weight, according to Eric Westman, MD, associate professor of medicine at Duke University.
Those already diagnosed with diabetes can also benefit from such lifestyle changes, although it's unclear how long they can control their blood sugar without medication. Typically, diabetes is treated with drugs that lower blood sugar and avert (or postpone) the need for insulin injections. "There are lots of short-term data—usually encompassing weeks to a year—showing that weight loss can ameliorate diabetes, decrease glucose levels, and reduce or even eliminate the need for medication," says David M. Nathan, MD, a professor of medicine at Harvard Medical School and chairman of the Diabetes Prevention Program, which conducted the prediabetes study. A just-launched federal trial called Look Ahead should reveal more in the coming decades.
For further information, call the American Diabetes Association at 800-diabetes or go to the federal government's National Diabetes Information Clearinghouse website, diabetes.niddk.nih.gov.