Prediabetes diet: What to eat if you’re at risk

Prediabetes diet
Many leading experts in diabetes and prediabetes recommend following a low-carbohydrate diet

Diet plays such a crucial role in managing – and, in some cases, reversing – prediabetes that you ignore it at your peril. The condition increases the risk of cardiovascular disease and stroke by at least 30 per cent for men and up to 50 per cent for women. Up to 70 per cent of people with prediabetes will go on to develop diabetes – unless they change their diet and lifestyle and take steps to reverse it.

What you eat has never been more important. Here’s our guide to the right diet to follow.

Jump to:

What is prediabetes?

Also known as non-diabetic hyperglycaemia, it’s a condition where your blood sugar levels are higher than normal but not yet high enough to be diagnosed as Type 2 diabetes.

The risk factors for prediabetes are broadly similar to those for Type 2 diabetes – particularly being overweight or obese and over the age of 45.

Prediabetes is estimated to affect around 5.1 million people in England, according to Diabetes UK. In people under 40, there has been an increase of almost a quarter in the same period – and experts fear that this is just the tip of the iceberg. According to Diabetes.co.uk, around seven million people are estimated to have prediabetes in the UK.

Why is my diet important in managing pre-diabetes?

Dr David Cavan, a consultant endocrinologist and the author of How to Reverse Type 2 Diabetes and Prediabetes, says: “Prediabetes doesn’t need medication. It doesn’t need exercise. The most important thing is that people need to change what they are eating. Doing this very powerfully treats, and can reverse prediabetes, in a very high number of people.”

Many leading experts in diabetes and prediabetes recommend following a low-carbohydrate diet which involves excluding white grains, sugar and starchy foods in favour of lean meat, vegetables and legumes. One of those experts is Dr David Unwin, who pioneered the approach in the UK and found that 93 per cent of his patients with prediabetes restored their blood sugars to normal after following the diet for two years.

Recommended foods for prediabetes

In order to help bring blood glucose back into balance, build meals around the following foods:

Lean proteins

  • Fish

  • Eggs

  • Dairy such as yogurt, cheese, cottage cheese, milk

  • Tofu and pulses such as lentils and chickpeas

“Getting adequate protein, and spreading protein across the day is vital,” says Carin Hume, a consultant dietitian. Aim to include a good source or protein with every meal.

Eggs on wholegrain toast can up your protein and fibre intake
Eggs on wholegrain toast can up your protein and fibre intake - Getty

Have two servings of fish each week and no more than 70g of red meat per day, but you can also include eggs, yogurt, cheese, cottage cheese, milk, tofu and pulses such as lentils and chickpeas to boost your protein intake.

Vegetables

“Fill your plate with protein and vegetables, particularly leafy green vegetables, and have what I would call a ‘good old fashioned meat-and-two-veg’ type of meal, rather than a rice- or pasta-based meal,” says Dr Cavan. Add salad or vegetables to at least two of your meals and choose as many different varieties as possible to feed your gut bacteria.

Fibre-rich foods

  • High-fibre beans and pulses such as lentils and chickpeas

  • Grains such as buckwheat, quinoa and barley

Research shows that a high-fibre diet can improve glucose metabolism, but Hume warns that many of us aren’t eating enough. As well as vegetables and salads, build high-fibre beans and pulses into your diet.

Healthy fats and omega-3s

  • Olive oil

  • Avocado

  • Oily fish

  • Nuts and seeds, such as flax and chia

Choose healthy fats, particularly heart-healthy monounsaturated and polyunsaturated fats from olive oil and avocado, oily fish and nuts and seeds. An increasing body of research now advocates eating full-fat dairy to help manage blood glucose. Eating nuts can help to improve blood sugar control, and one study found that eating seeds such as flax and chia has the same effect.

Back to page navigation

Food and drink to avoid with prediabetes

  • Liquid calories including juices, sugary drinks, smoothies

  • Alcohol

“Try to make water your main drink, and only consume alcohol in moderation, says Dr Cavan. “I see a lot of people making fruit smoothies because they think they are really healthy, but you can have a huge amount of sugar in a smoothie.”

Processed and refined foods

  • Flavoured yogurts and sauces

  • Refined sugars (found in most shop-bought cakes and breakfast cereals)

Consuming a lot of ultra-processed foods (UPFs) increases the risk of developing Type 2 diabetes – perhaps by as much as 15 per cent. “Most UPFs are highly palatable and easy to overeat,” notes Hume.

While smoothies may seem healthy, they can be full of sugar
While smoothies may seem healthy, they can be full of sugar - Getty

Avoid foods which contain refined sugars, such as cakes, biscuits, breakfast cereals and sweets, along with those which often contain large amounts of hidden sugars, such as flavoured yogurts and sauces. Instead include protein in every meal and fill half your plate with vegetables or salad.

Managing portion sizes

Portion size is important, especially in reducing calorie intake to help with weight loss,” says Hume. On that note, “it may be better to enjoy ‘treat foods’ when eating out as this can make portion control easier, especially if you share dishes and desserts.”

If the thought of cutting out all the sugars and starchy foods feels too much, Dr Cavan recommends using a blood glucose monitor such as the Freestyle Libre to see exactly how your body responds to the foods you eat. This might make you pause before reaching for the biscuit tin.

“This will show you instantly which things are pushing up your sugar levels,” says Dr Cavan. “You can quickly see what you can get away with, and this is so variable. For example, some people can have a small amount of potato and they don’t see any effect, while other people can’t.”

FAQs

Is fasting helpful for prediabetes?

Research suggests that fasting or time-restricted eating can help to improve blood glucose control and potentially prevent or treat prediabetes.

“Prolonging your overnight fast can help reduce the insulin levels in your bloodstream, which helps to counter the pre-diabetes disease process,” explains Dr Cavan. “The main form of fasting that I suggest is to skip breakfast on two or three days (or more) per week. This type of 16-hour fast can be very helpful, especially for people who aren’t hungry in the morning.”

How will I know if I have prediabetes?

“The only way you can tell if you have prediabetes is by asking your GP for a routine blood test,” says Dr Cavan. “When you have prediabetes you have a blood sugar level that’s slightly higher than normal, but nowhere near high enough to cause any symptoms, such as being very thirsty or tired, or passing a lot of urine.”

Your doctor will measure your HbA1C level, which shows your average blood glucose levels for the previous three months. If your HbA1C reading is between 42mmol/mol (6 per cent) and 47mmol/mol (6.4 per cent), this indicates prediabetes. Over 48mmol/mol (6.5 per cent) suggests diabetes.

Back to page navigation