What is the prediabetes diet?

• Impaired glucose tolerance
• Above normal glucose blood levels after fasting
• Above normal glycated haemoglobin (HbA1c)
• Borderline diabetes

Visit our ‘All you need to know about diets’ page for recipes and more expert advice on weight loss, including low-GI and the Mediterranean diet

How will I know if I have prediabetes?

Prediabetes is diagnosed following a blood test because you are unlikely, at this stage, to be presenting symptoms. However, if you are over 45 years old or overweight, have a parent or sibling with type 2 diabetes, have a sedentary lifestyle, have in the past been diagnosed with gestational diabetes or PCOS, or are a certain ethnicity, you may be more likely to develop the condition. If you meet one or more of these criteria and are concerned, contact your GP for further guidance.

Why is prediabetes bad for my health?

If you’ve been told you are prediabetic, this is a warning that you are at increased risk of developing type 2 diabetes, and as a result are more likely to have heart disease or a stroke. It's estimated that 12.3 million people in the UK are in this category. Being at risk doesn’t mean you’ll definitely develop type 2 diabetes, but it does mean that without changes to your diet and lifestyle you are more likely to.

If you do develop type 2 diabetes, it can significantly impact the quality of your life and reduce your life expectancy. That’s because people with persistently high blood sugar are at risk of damaging their blood vessels and overtime this may lead to issues such as kidney failure, blindness and serious nerve damage.

That said, there are lots of things you can do to reduce your risk or delay the onset of type 2 diabetes.

How does diet play a role in prediabetes?

Research suggests that the amount and type of carbohydrate we eat plays a significant role in whether we develop prediabetes. This is because all carbs are broken down by the body to glucose for energy, the amount of glucose in the blood at any point in time is carefully controlled by the hormone insulin. However, as we age, eating a consistently poor diet, doing little exercise, smoking and our genetics can all make insulin less effective at doing its job.

Many of us think of sugary foods like biscuits, cakes, jam and chocolate when we think of managing diabetes, but starchy foods like bread, rice, pasta and potatoes will also influence our blood sugar. That’s because all types of carbohydrates increase blood glucose levels, although some have a slower effect than others. These slow-releasing foods are a better choice and are typically referred to as low-GI foods, they include foods rich in fibre like wholegrains, beans and pulses.

Understanding the glycaemic index (GI) of foods can be helpful in managing your blood sugar levels, but it is only one tool. Adopting a healthy, balanced diet which includes your five a day (more if possible), lean protein, some fat, and foods which are low in sugar and salt will also support your ability to manage your blood sugar.

What are the key components of the prediabetes diet?

There is no specific diet for prediabetes, but there are some important modifications you can make to your diet. These include:

• Eat more whole fruit and vegetables, especially the non-starchy variety like green leaves, broccoli and asparagus. Other useful inclusions are those rich in a compound called nitrate, these include celery, rhubarb and beetroot – including these may help reduce blood pressure and improve circulatory health.
• Make wholegrains your staple, such as jumbo oats, barley, rye, wholewheat flour, wholegrain rice, especially basmati or wild rice.
• Choose lean sources of protein. These help keep you full and reduce the urge to snack – examples include chicken breast, fish and seafood, legumes, unsalted nuts and seeds.
• Include some dairy such as yogurt and cheese, or fortified plant-based alternatives.
• Minimise refined ‘white’ carbs, sugar, sweetened drinks and starchy veg like potatoes.
• Minimise red and processed meats, aiming to keep within guideline amounts.
• Minimise the saturated and trans fats in your diet, focusing instead on the heart-healthy fats in oily fish, nuts and seeds, as well as fruit like olives and avocado.

Don’t forget:

• Wise-up on portions – it may be useful to weigh out your pasta and rice until you can gauge the appropriate quantity for a serving.
• Cook clever – avoid over-cooking foods like rice and pasta, instead create more ‘resistant starch’ by cooking, cooling and thoroughly reheating carbs such as rice, pasta and potatoes.
• Plate up perfectly – fill half of your plate with non-starchy vegetables, a quarter with lean protein and the final quarter with wholegrains.

What else should I do if I have been told I have prediabetes?

As well as adopting a healthy, balanced diet, there are a number of other things you can do to reduce your risk of developing type 2 diabetes:

• Being physically active.
• Achieving and maintaining a healthy weight.
• If you’re a smoker, stop.

If you are considering a change in diet, please consult your GP to ensure you can do so without risk to health.

Further reading

What is diabetes?
How to eat to manage diabetes
Type 2 diabetes in children
What are low-carb diets?

This article was updated on 22 May 2024 by Health Editor Emma Hartfield

Kerry Torrens BSc. (Hons) PgCert MBANT is a BANT Registered Nutritionist® with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including Good Food.

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