Diabetes affects more than 20 million Americans, and 57 million Americans have prediabetes (early type 2 diabetes). There are many common risk factors to both type 1 and type 2 diabetes, but some are more specific to one or the other. Here’s a comprehensive overview of risk factors.

Family History

Genetics play a role in determining how likely you are to develop some type of diabetes. Although researchers don’t fully understand the role of genetics in the development of diabetes, statistics show that if you have a parent or sibling with diabetes, your odds of developing it yourself increase.

Age

According to the American Diabetes Association, about one in 13 people in the United States have diabetes. But statistics show that your risk of type 2 diabetes increases as you get older, especially after age 45. In fact, more than 80 percent of cases occur in people over age 45, though recent statistics indicate that the incidence of type 2 diabetes is increasing dramatically among children, adolescents, and younger adults. Likely factors include reduced exercise, decreased muscle mass, and weight gain as you age. Type 1 diabetes is usually diagnosed by the age of 30.

Obesity

Excess body fat—especially around your middle—can lead to insulin resistance and increased blood sugar levels. Research suggests that excess fatty tissue can trigger inflammation in the body that leads to insulin resistance. But many people who are overweight never develop diabetes, so research remains inconclusive on the link between obesity and diabetes.

Poor Diet

Studies have shown that malnutrition—especially low protein and fiber intake—is a contributing factor in developing type 2 diabetes. A diet high in calories, fat, and cholesterol raises your risk, as does obesity, which increases your body’s resistance to insulin.

Lack of Exercise

Studies show that exercise makes muscle tissue more responsive to insulin, which is why regular exercise such as aerobic and/or resistance training can help lower your risk of diabetes. Talk to your healthcare provider about an exercise plan that’s right for you.

Ethnicity

Although research is inconclusive, some ethnic groups (particularly African Americans, Native Americans, Asians, Pacific Islanders, and Hispanic Americans) have a higher incidence of diabetes.

Gestational Diabetes

Women who develop gestational diabetes during pregnancy are at higher risk for developing type 2 diabetes later in life. Women who deliver a baby weighing more than 9 pounds are also at greater risk.