Age and overweight (or obesity) are the most common traits that make someone likely to develop type 2 diabetes, but hormones may also have something to do with it. A family history of diabetes, prediabetes, minority ethnicity (Hispanic, African American, Native American, Asian, or Pacific Islander), high blood pressure, cardiovascular disease or abnormal cholesterol levels, and inactivity also put people at higher risk of developing diabetes. For women, having high blood pressure develop during pregnancy (called preeclampsia), diabetes during pregnancy (called gestational diabetes), or polycystic ovary syndrome raise the risk even more.

• Get tested. The CDC estimates that more than a quarter of people who have diabetes haven’t been diagnosed. The American Diabetes Association recommends that you get tested every 3 years starting at age 45, especially if you are overweight. The US Preventive Services Task Force recommends that adults with blood pressure above 135/80 be screened every 3 years. If you have some additional risks, such as a family history of diabetes, then you should get tested more frequently.
• Diet and exercise. Yes! The best way to prevent diabetes is with a healthy lifestyle. The National Institutes of Health sponsored a Diabetes Prevention Program trial that used “intensive” lifestyle training. The participants in this large clinical trial were overweight and had prediabetes. More than two thirds of them were women, and nearly half were from an ethnic minority group. Some got intense training to change their diet, physical activity, and habits with the goal of losing just 7% of their body weight. Another group took the diabetes drug metformin and got standard advice about diet and exercise. A third group got the standard advice only. The modest but focused lifestyle change did more than anything else to prevent diabetes. It reduced the number of new diabetes cases 58% more than standard advice alone. In contrast, metformin plus standard advice didn’t do nearly as well, reducing the number of diabetes cases 31% compared with standard advice. The message is that many people can benefit from adopting such habits.