As many as 3.2 million people in the UK are prediabetic according to Diabetes UK; that is, they are at risk of developing Type 2 diabetes (T2D) due to higher than normal blood glucose levels. Left unchecked, this can lead to serious health complications, including heart disease, stroke and damage to the eyes and nerves.
Prediabetes doesn’t have any symptoms, so most people won’t realise they have it, but the risk factors for developing T2D are well-documented, including being overweight or obese, smoking and lack of physical activity, as well as non-lifestyle factors such as age and ethnicity.
Only a blood test can tell if you are pre-diabetic or not, but lifestyle changes, in particular improving diet quality, are key to preventing and even reversing T2D. One study, which analysed 4.1 million person-years [a measurement that accounts for the number of people in a study and how long they spend in it] of data, revealed that those most closely following a healthy plant-based diet had a 34 per cent lower risk of developing diabetes than those who did not.
The worst food offenders, when it comes to diabetes risk, are ultra-processed sugary and fatty foods and processed meats, but there are a few foods to avoid, or at least limit, in your diet that you may find surprising.
1. High sugar fruits and dried fruit
While fruit is an integral part of a healthy diet, a few fruits, such as red grapes, red apples, bananas, mango and pineapple, are particularly high in sugar and should be eaten in smaller amounts. Similarly, drying fruit concentrates the sugars present, and while they can still be enjoyed as part of a healthy diet, try to limit consumption to 30g (or around one heaped tablespoon) per day.
Top tip
Mitigate potential blood sugar spikes by pairing sugary fruits with healthy fats and protein. Have a date filled with peanut butter or an apple with a slice of cheese.
2. Fruit juices
When fruit is juiced, much of the fibre is removed, which concentrates the sugar and causes it to be absorbed into the bloodstream more quickly. It’s this blood sugar roller-coaster that, over time, can lead to insulin resistance, the precursor for T2D.
Top tip
Have a smoothie rather than juice as more of the fibre is retained, and add oats and/or seeds to the mix. If having juice, limit your portion size to 150ml and consume foods that contain protein and fibre, like eggs on wholegrain toast.
3. Fruit jams
Fruit jams and preserves can be as much as 60 per cent sugar. Eating jam on toast, particularly fibre-rich wholegrain toast, reduces the overall glycaemic load (the rate at which a food raises blood glucose levels), but it’s still a high-carb combo that’s not the best choice for pre-diabetics.
Top tip
Make some low-sugar chia jam by placing 300g of fresh or defrosted frozen fruit in an airtight container; add 50ml water, 1 tsp lemon juice and 2 tbsp chia seeds. Mash together, pop on the lid, and place in the fridge for a couple of hours to thicken. This will keep for up to 4 days.
4. Flavoured yogurts
Plain, live yogurt is a brilliant source of protein and contains lots of gut-friendly bacteria, but most flavoured yogurts have lots of added sugar. Some of the top brands I checked contained as much as four teaspoons per serving.
Top tip
Now you’ve got your chia jam in the fridge, buy a good quality plain Greek yogurt and have a few tablespoons with a generous dollop of jam on top.
5. Rice cakes
Rice cakes may be marketed as a low-calorie healthy choice, but they are also low in protein and fibre – and often low in taste too. Comprised almost entirely of starchy carbohydrates, they have a very high glycaemic index and so will quickly spike blood sugars.
Top tip
Choose wholegrain, seedy crackers which contain more fibre instead and select toppings with plenty of healthy fat and protein, such as avocado, feta or hummus.
6. Diet fizzy drinks
It’s no secret that fizzy drinks are high in sugar; a regular Coke has 35g per 330ml can (which is 39 per cent of your recommended daily intake), so sugar-free diet drinks would seem a good alternative for pre-diabetics. However, recent studies have found that the artificial sweeteners used in these drinks, such as aspartame and sucralose, may also prompt insulin resistance over time.
Top tip
If you love a fizzy drink, stick to sparkling water. You can always flavour it by adding slices of fresh lime, lemon, strawberries or cucumber.
7. ‘Healthy’ sweeteners
In the quest to avoid refined sugar, sweeteners such as honey and maple syrup are often considered healthier natural alternatives. But the truth is they still raise blood sugar levels and should be consumed only in small amounts.
Top tip
Fresh dates have a low glycaemic index thanks to the fibre they contain. Make a fresh date sweetener by blending 200g pitted Medjool dates, 2 tsp lemon juice and 300ml water until smooth. Store in the fridge in an airtight container for up to 3 weeks.