Can Type 2 Diabetes Be Prevented?

Prediabetes and type 2 diabetes both involve higher-than-normal blood sugar levels, but they are not the same.

Prediabetes means blood sugar is higher than normal but not high enough for a type 2 diagnosis. It often has no clear symptoms, so many people do not know they have it.

“Prediabetes can be easy to overlook because you may feel perfectly healthy. But even without symptoms, it's important to know your numbers and understand your risk,” says Dr. Tsimikas.

The key difference is how high your blood sugar is and how your body responds to insulin. Type 2 diabetes develops when the body does not use insulin well, causing blood sugar levels to rise too high. Over time, high blood sugar can damage blood vessels and nerves, increasing the risk of heart disease, kidney disease, vision problems, nerve damage and other serious complications.

Prediabetes is common. According to the Centers for Disease Control and Prevention (CDC), about 115 million U.S. adults — more than 2 in 5 — have prediabetes, and about 8 in 10 do not know they have it. An estimated 40 million people in the U.S. have diagnosed or undiagnosed diabetes.

Having prediabetes does not mean you will develop type 2 diabetes. Lifestyle changes and, when appropriate, treatment can improve blood sugar and lower your risk.

Prediabetes usually does not cause noticeable symptoms. A blood test may be the only way to know whether your blood sugar is higher than normal. 

Tests used to diagnose prediabetes include:

• A1C: 5.7% to 6.4%
• Fasting blood glucose: 100 to 125 mg/dL
• Two-hour oral glucose tolerance test: 140 to 199 mg/dL

The American Diabetes Association recommends routine screening for prediabetes and type 2 diabetes beginning at age 35. Your doctor may recommend testing sooner if you are overweight or have obesity and other risk factors.

Risk factors include:

• Overweight or obesity
• Family history of type 2 diabetes
• Not getting enough physical activity
• A history of gestational diabetes
• Polycystic ovary syndrome
• High blood pressure
• High cholesterol
• Certain racial, ethnic or ancestry groups associated with a higher risk of diabetes

You don’t have to lose a lot of weight to see a benefit. If you are overweight or have obesity, losing about 5% to 7% of your body weight can significantly lower your risk of developing type 2 diabetes, according to the CDC. For someone who weighs 200 pounds, that’s about 10 to 14 pounds.

Focus on gradual, sustainable changes rather than restrictive diets or rapid weight loss. 

Regular physical activity can help your body use insulin more effectively, manage blood sugar and maintain a healthy weight.

Aim for at least 150 minutes of moderate-intensity activity each week. Brisk walking, swimming and cycling are good options. You can spread your activity throughout the week, such as by walking for 30 minutes, five days a week.

Choose activities you enjoy rather than ones you feel you’re supposed to do. Starting with something manageable and gradually doing more can make it easier to stay active and build a routine.

There’s no single diet for preventing type 2 diabetes. Instead, focus on an overall eating pattern that includes vegetables, fruits, whole grains, beans, nuts, lean proteins and other minimally processed foods.

Try to limit foods and drinks high in added sugars, refined carbohydrates and saturated fat. A Mediterranean-style diet can be a good option. It emphasizes vegetables, fruits, whole grains, beans, nuts, fish and other nutritious foods.

The best eating plan is one that meets your nutritional needs, fits your lifestyle and is realistic to follow over time. 

Planning meals ahead can make healthy choices easier and help you avoid overeating.

One simple approach is to fill half your plate with nonstarchy vegetables. Divide the other half between lean proteins and whole grains or other nutritious carbohydrate foods.

Nutrition labels can also help you make informed choices. Compare serving sizes, added sugars, saturated fat and other nutrients when choosing between foods.

You don’t have to eat perfectly to help prevent diabetes. Focus on healthy habits you can follow consistently.

Healthy sleep and stress management can make it easier to maintain other healthy habits.

Getting too little or too much sleep, as well as poor-quality sleep, has been associated with a higher risk of type 2 diabetes. If you regularly have trouble sleeping or don’t feel rested, talk with your healthcare provider.

Managing stress can also help you stay active, eat well and maintain healthy routines. Try activities that help you relax, such as walking, meditation or deep breathing.

Prediabetes is an opportunity to make changes that can help prevent or delay type 2 diabetes. "A diagnosis of prediabetes doesn’t mean you’re destined to develop diabetes. It gives you a chance to make changes now that can have a lasting impact on your health," Dr. Tsimikas says.

The Scripps Diabetes Prevention Program, part of the CDC-led National Diabetes Prevention Program, offers a year-long program for eligible adults with prediabetes. Participants work with trained lifestyle coaches to build lasting habits around nutrition, physical activity, weight management and stress.

If you have prediabetes or think you may be at risk for type 2 diabetes, talk with your healthcare provider about testing and steps you can take now to lower your risk.