How insulin resistance becomes prediabetes
Think of it as two stages. In the first, your cells respond poorly to insulin and the pancreas makes extra to cover the gap. Glucose tests stay normal. In the second, the pancreas can no longer cover the gap at every meal, so glucose rises above normal but not yet into the range for diabetes. That second stage is prediabetes.
The US Centers for Disease Control and Prevention estimates that more than one in three American adults has prediabetes, and most of them do not know. Rates in Europe are also high, though definitions differ between countries.
What the numbers mean
| Test | Normal | Prediabetes (ADA) | Diabetes |
|---|---|---|---|
| Fasting glucose | Below 100 mg/dL (5.6 mmol/L) | 100 to 125 mg/dL (5.6 to 6.9 mmol/L) | 126 mg/dL (7.0 mmol/L) or more |
| HbA1c | Below 5.7% (39 mmol/mol) | 5.7 to 6.4% (39 to 47 mmol/mol) | 6.5% (48 mmol/mol) or more |
| 2-hour glucose tolerance test | Below 140 mg/dL (7.8 mmol/L) | 140 to 199 mg/dL (7.8 to 11.0 mmol/L) | 200 mg/dL (11.1 mmol/L) or more |
The UK's NICE and the WHO use slightly higher lower limits for fasting glucose and HbA1c (for example HbA1c 42 to 47 mmol/mol in the UK), so the same result can be labeled differently on either side of the Atlantic. Your doctor will use the local criteria.
What the research shows about reversing it
The Diabetes Prevention Program, a large US trial, enrolled adults with prediabetes. Participants who followed an intensive lifestyle program, aiming for about 7 percent weight loss and 150 minutes of activity a week, reduced their risk of developing type 2 diabetes by 58 percent over roughly three years. Metformin reduced it by 31 percent. Ten years later the lifestyle group still had a lower rate of diabetes than the comparison group.
Many people with prediabetes can also bring their numbers back to the normal range. It is worth treating this as a window, not a sentence.
A practical food plan for prediabetes
- Aim for 25 to 38 grams of fiber a day. Women's target is about 25 g and men's about 38 g. Most adults are well under that. Build up over a few weeks.
- Make beans and lentils a daily habit. They give you protein, slow carbohydrate and fermentable fiber in the same bite.
- Swap soft starch for chewy starch. Barley, bulgur, steel-cut oats, al dente pasta and intact grains digest slower than white bread or instant rice.
- Use vinegar. A tablespoon or two in a dressing with a starchy meal has been shown to modestly lower the after-meal glucose rise.
- Drop liquid sugar first. Sodas, sweetened coffee drinks and juice send sugar into the blood faster than any food.
- Walk after meals. Ten to fifteen minutes is enough to see a difference.
Prediabetes recipes people rarely try
Pearl barley is one of the best-studied grains for blood sugar because of its beta-glucan fiber, and it makes a creamy risotto without any rice. Chickpeas with a sharp vinegar dressing give you two proven tricks in one bowl. Both are below.
When to see your doctor
Ask for repeat testing every year if you have prediabetes. If you have a family history, past gestational diabetes, PCOS, or you are over 35, ask about screening even when you feel well.
Mushroom and Pearl Barley Risotto
Pearl barley cooks up creamy and chewy, just like arborio rice, but carries far more fiber and a type of soluble fiber called beta-glucan that blunts the sugar spike.
High-Fiber Chickpea Salad with Vinegar Dressing
Chickpeas and vinegar are a classic pairing in the kitchen.
Quick recipes for prediabetes
Every recipe below takes 30 minutes or less and is built around fiber, protein and slow carbohydrate. Browse the full recipe collection for more.
- Quick Mushroom Barley Risotto (25 Minutes) (25 min): Barley is the easiest way to get the creamy texture of risotto with several times the fiber of white rice.
- Red Lentil Tomato Soup (20 Minutes) (20 min): Red lentils are the fastest legume there is.
- Black Bean and Egg Breakfast Skillet (15 min): A breakfast built on beans and eggs gives you slow carbohydrate, fiber and protein before the day starts.
- Cinnamon Walnut Oatmeal with Chia (10 Minutes) (10 min): Plain instant oatmeal digests quickly.
- Garlic Edamame Broccoli Stir-Fry (15 Minutes) (15 min): Edamame is one of the few plant foods with complete protein, and it is low in digestible carbohydrate.
- High-Fiber Chickpea Salad with Vinegar Dressing (15 min): Chickpeas and vinegar are a classic pairing in the kitchen.
References
- Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002;346:393-403.
- Diabetes Prevention Program Research Group. 10-year follow-up of diabetes incidence and weight loss in the DPP Outcomes Study. Lancet 2009;374:1677-1686.
- American Diabetes Association. Diagnosis and classification of diabetes: Standards of Care. Diabetes Care, current edition.
- Centers for Disease Control and Prevention. National Diabetes Statistics Report.
Please note. This page is for education and is not medical advice. If you take insulin or medication that can cause low blood sugar, such as a sulfonylurea, talk to your care team before making large changes to what you eat. Read our medical disclaimer.