What is the prediabetes diet?

In clinical terms ‘prediabetes’ defines a patient with:

• Impaired glucose tolerance with blood sugar levels above normal but not high enough to be classed as diabetic
• Above normal glucose blood levels after fasting
• Above normal glycated haemoglobin (HbA1c)
• Borderline diabetes.

How will I know if I have prediabetes?

To be diagnosed as prediabetic, you will need a blood test. You may be more likely to have it you are:

• Over 45 years old
• Overweight
• Have a parent or sibling with type 2 diabetes
• Have been diagnosed with gestational diabetes or PCOS
• You are a certain ethnicity.

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, you have a higher 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.

Developing type 2 diabetes may even reduce your life expectancy as persistently high blood sugar can put you at risk of damaging blood vessels and overtime this may lead to issues such as kidney failure.

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 developing prediabetes.

All carbs are broken down by the body into glucose to be used for energy – the amount of glucose in the blood is then carefully controlled by the hormone insulin. However, ageing, eating a consistently poor diet, doing little exercise, smoking and our genetics can all make insulin less effective at doing its job.

As well as sugary foods like biscuits, cakes and chocolate, starchy foods like bread, rice, pasta and potatoes will also influence your blood sugar levels. While all types of carbohydrates increase blood glucose, there are some which 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 fibre-rich foods 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 plenty of colourful fruits and vegetables, lean protein, good fats 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 leafy veg, broccoli and asparagus. Also opt for foods which are rich in a compound called nitrate, including celery, rhubarb and beetroot – these may help to reduce blood pressure.
• Make wholegrains your staple, such as jumbo oats, wholewheat flour, wholegrain rice, in particular basmati and wild rice.
• Choose lean sources of protein, these help keep you full and as a result may reduce your urge to snack – examples include chicken breast, fish and seafood, beans and pulses, unsalted nuts and seeds.
• Include some dairy such as yogurt and cheese, or plant-based alternatives.
• Minimise refined ‘white’ carbs, sugar, sweetened drinks and starchy vegetables, 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 what an appropriate quantity for a single serving actually is.
• Cook clever – avoid overcooking foods like rice and pasta, instead create more ‘resistant starch’ by cooking, cooling and thoroughly reheating carbs like rice, pasta and potatoes.
• Plate perfectly – fill half of your plate with non-starchy vegetables, a quarter with lean protein and the final quarter with wholegrains.

Do I need to track my blood sugar levels?

Although previously only available on prescription for those diagnosed with diabetes, continuous blood glucose monitors (CGMs) are now widely available and have seen a recent boom in popularity.

These devices pierce the skin to measure blood sugar levels and send the results to your phone. However, there’s little data to support the use of these devices in people without diabetes, although some small studies suggest there may be some motivational benefits in terms of increasing activity levels, making better food choices and encouraging users to eat earlier in the day. That said, there are other studies that queried the accuracy of CGMs when compared with capillary blood glucose measurements.

Experts argue that CGMs allow for earlier diagnosis of prediabetes or diabetes and may be helpful for people at higher risk. Atlhough there is currently no data or guidance suggesting a need for these devices in those who are healthy.

Ready more about blood sugar and how to manage it in our expert guide.

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:

• Keep physically active – taking regular walks will offer numerous benefits, including helping to balance blood sugar levels after eating. This is because moving your body helps improve how your body responds to insulin.
• Achieve and maintain a healthy weight.
• If you’re a smoker, stop. Having diabetes will increase the harm caused by smoking.
• Focus on your dental hygiene to avoid or minimise the damaging effects of gum disease.
• Keep your alcohol intake within guideline amounts.

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
I'm a diabetic but why is everyone suddenly obsessed with blood sugar?
Type 2 diabetes in children
What are low-carb diets?

This article was updated on 21 July 2025 by Kerry Torrens

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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