Prediabetes diet: What to eat if you’re at risk
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.
So, what you eat has never been more important. Here’s our guide to the right diet to follow:
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.
According to Diabetes UK, one in five adults in the UK are living with prediabetes and diabetes. It is estimated prediabetes affects 6.3 million people, but some are unaware they have it. Left untreated, prediabetes could turn into type 2 diabetes.
Diagnosing 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.
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
Sources include:
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.
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
Load up on 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
It is well known 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, add in the following:
High-fibre beans and pulses such as lentils and chickpeas
Grains such as buckwheat, quinoa and barley
Healthy fats and omega-3s
To get more omega-3 in your diet, try eating the following:
Avocado
Oily fish
Nuts and seeds, such as flax and chia
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.
Food and drink to avoid with prediabetes
“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.”
Avoid the following:
Flavoured yogurts and sauces
Refined sugars (found in most shop-bought cakes, biscuits, sweets and breakfast cereals)
Liquid calories including juices, sugary drinks, smoothies
Excessive amounts of alcohol
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.
Avoid the foods listed above, and 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.”
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.”
