How to Reverse Prediabetes: Diet, Exercise, Medicines and Follow-Up

Prediabetes is a warning light. Blood sugar has risen above normal, and the body is struggling with insulin resistance, but diabetes has not yet developed. Without action, many people with prediabetes go on to develop type 2 diabetes within several years. With action, a large number return to normal blood sugar. Because prediabetes causes no symptoms, most people find it on a routine test, so understanding the results is the first step.

Diagnosing prediabetes

Any one of these suggests prediabetes:

• HbA1c: 5.7-6.4% (39-47 mmol/mol)
• Fasting glucose: 100-125 mg/dL (5.6-6.9 mmol/L)
• 2 hours after a 75 g glucose drink: 140-199 mg/dL (7.8-11.0 mmol/L)

See the complete list of normal blood sugar ranges. Your doctor may repeat the test to confirm it. Prediabetes also raises the risk of heart disease and fatty liver, so blood pressure and cholesterol should be checked.

Who is at risk

South Asians develop insulin resistance at lower body weights. Risk rises with a BMI of 23 or more, a waist of 90 cm or more in men and 80 cm or more in women, family history of diabetes, PCOS, previous gestational diabetes, high blood pressure, fatty liver, inactivity and poor sleep. Check your BMI with our BMI calculator, and read about Asian BMI cutoffs.

What the evidence shows

In the US Diabetes Prevention Program, adults with prediabetes who lost about 7% of their weight and exercised 150 minutes a week reduced their chance of developing diabetes by 58% over three years. Similar results were seen in studies in Finland, China and India, and benefits persisted for many years. Lifestyle change was more effective than metformin in most age groups.

Step 1: Aim for 5-7% weight loss

For a person weighing 80 kg this means losing 4-5.6 kg. Aim for 0.25-0.5 kg a week by creating a small daily calorie deficit rather than starving. Use our TDEE calculator to estimate your daily energy needs. Even if you cannot lose weight, improving diet and activity still lowers sugar.

Step 2: Change what you eat

• Use the plate method: half vegetables and mallum, a quarter protein, a quarter starch.
• Reduce rice and bread portions, choosing red rice, kurakkan, oats or whole-grain options.
• Cut sugary drinks, including sweetened tea, soft drinks and packaged juice.
• Choose pulses and fish more often, and limit fried foods and processed meat.
• Eat fruit in small portions instead of juices.
• Limit sweets and bakery items to rare occasions.

See our diabetic diet guide for Sri Lanka for a sample day of meals.

Step 3: Move more

• At least 150 minutes of brisk walking, cycling or swimming each week, spread over most days.
• Strength training twice a week, because muscle takes up sugar from the blood.
• A 10-15 minute walk after meals lowers post-meal sugar.
• Break up long sitting with a few minutes of walking every 30-60 minutes.

Step 4: Sleep, stress and habits

Poor sleep and chronic stress worsen insulin resistance. Aim for seven to eight hours. Stop smoking, limit alcohol, and ask your doctor about loud snoring with daytime sleepiness, which can indicate sleep apnoea.

Is medicine needed?

Metformin may be considered for people with prediabetes who have a BMI of 35 or more, are under 60, or have had gestational diabetes, or whose blood sugar keeps rising despite lifestyle change. It lowers the risk of diabetes but does not replace healthy living. Do not start any supplement or herbal remedy as a "cure" without medical advice.

Monitoring and follow-up

• Repeat HbA1c or fasting glucose at least once a year, or every 3-6 months if starting lifestyle changes.
• Check blood pressure, cholesterol and weight regularly.
• Return to normal readings means success, but continue the habits, because insulin resistance can return.
• If HbA1c reaches 6.5% or fasting glucose 126 mg/dL, you may now have diabetes and need further tests. Read the early symptoms of diabetes.

Set small goals

A realistic plan beats a perfect one. For example: walk 30 minutes after dinner five days a week, replace sweetened tea with plain tea, and reduce evening rice by a third. Review progress monthly and involve your family, because shared meals make change easier.

When to see a doctor

See a doctor if you have prediabetes, or if you notice excessive thirst, frequent urination, tiredness or weight loss. If you are pregnant or planning pregnancy with prediabetes, get specialist advice. Learn more in our article on whether diabetes can be cured or reversed.

References

• Diabetes Prevention Program Research Group, New England Journal of Medicine, 2002
• American Diabetes Association: Standards of Care in Diabetes, prevention or delay of diabetes
• World Health Organization: diabetes fact sheet