How to Prevent Type 2 Diabetes

Type 2 diabetes is one of the most preventable chronic diseases. In the landmark Diabetes Prevention Program, people with prediabetes who lost about 7% of their weight and exercised 150 minutes a week cut their risk of developing diabetes by 58% — and by 71% in people over 60.

Know your risk

Prediabetes usually causes no symptoms. Ask for a fasting glucose or HbA1c test if you are 35 or older, overweight with another risk factor, had gestational diabetes, or have a family history of diabetes. Prediabetes means fasting glucose of 100–125 mg/dL or HbA1c of 5.7–6.4%. See the levels chart.

1. Lose some weight — a little goes a long way

Losing 5 to 7 percent of body weight — 10 to 14 lb for someone weighing 200 lb — markedly improves insulin sensitivity. Losing fat around the waist and liver matters most.

2. Move 150 minutes a week

Brisk walking, cycling, swimming or dancing for 30 minutes on five days, plus muscle-strengthening exercise twice a week. Short walks after meals blunt glucose spikes. Break up long periods of sitting every 30 minutes.

3. Eat for steady blood sugar

• Fill half the plate with non-starchy vegetables, a quarter with protein, a quarter with whole grains or legumes.
• Choose whole foods over refined starch and sugar.
• Replace sugar-sweetened drinks with water, unsweetened tea or coffee.
• Eating patterns with good evidence: Mediterranean, DASH, plant-forward, and lower-carbohydrate approaches.

Ideas: 10 foods for steady blood sugar.

4. Sleep, stress and smoking

Aim for 7–9 hours of sleep and get snoring checked for sleep apnea. Chronic stress raises glucose through cortisol. Smoking increases the risk of type 2 diabetes by 30–40% — quitting helps at any age.

5. Get support

CDC-recognized lifestyle change programs (National Diabetes Prevention Program) offer a year of coaching, in person or online, and are covered by Medicare and many insurers for people with prediabetes. For some high-risk people, doctors consider metformin.

Can type 1 diabetes be prevented?

Not at present — it is autoimmune. Relatives of people with type 1 diabetes can be screened for autoantibodies, which allows early monitoring and, for some, treatment that delays onset.