What causes prediabetes?

What causes prediabetes in adults? 

If you have prediabetes, your average blood sugar levels are higher than they should be but below the range for type 2 diabetes. 

Your body isn’t making enough of the hormone insulin, which helps keeps blood sugar levels in a healthy range (below 42mmol). Or the insulin isn’t working very well, known as insulin resistance.

Prediabetes is triggered by a combination of factors individual. Your age (prediabetes risk increases are you get older)

• Family history (genes).
• Living with overweight or obesity – which makes it harder for your body to manage the level of sugar in your blood.
• Having more fat stored in and round your organs, which stops them working so well to control blood sugar levels (sometimes indicated by a high waist measurement - known as your waist to height ratio.
• Your ethnicity – if you’re from a Black African, African Caribbean and South Asian (Indian, Pakistani, Banghadeshi background), your risk of prediabetes is higher and at a younger age and lower bodyweight than someone from a White European background.
• Other medical conditions.
• Poor quality sleep.
• Smoking.

Other things that can increase your risk of prediabetes — and type 2 diabetes — are statins and steroids.

If you want to help prevent prediabetes, follow our tips for how to prevent type 2 diabetes. The advice is the same.

What causes prediabetes in children and young people?

Prediabetes in children and young adults is trigged by a combination of the same risk factors as adults. Because there are no symptoms, it's important to be aware of the risk factors. 

One of the well-known risk factors for prediabetes and type 2 diabetes is living with overweight or obesity but it doesn't on its own cause prediabetes (or type 2 diabetes). Family history, ethnicity and other factors can also play a role. 

If you’re worried your child is at risk of developing prediabetes or type 2 diabetes, we’re here to help with tips and support. Call our helpline on 0345 123 2399. 

See our pages on  children and type 2 diabetes and young people and type 2 diabetes. 

Is prediabetes caused by genes (passed down through the family?)

If your family has a history of diabetes (genes), this puts you at risk of prediabetes and type 2 diabetes.

But even if prediabetes runs in your family (genes), some family members may develop the condition, but others may not.

That’s because prediabetes is trigged by a combination of factors. Although family members share the same genes, their weight, diet, physical activity levels and age will be different.

Am I to blame for my prediabetes? 

We know it can be a shock to be diagnosed with prediabetes. But you are not to blame. 

There is information and support available to help you make health changes, which can help stop prediabetes progressing into type 2 diabetes. If you want to chat things through, do call our helpline on 0345 123 2399.

Prediabetes and body fat 

Our research has shown that how and where the body stores fat, and not just overall weight, is important when it comes to risk of prediabetes and type 2 diabetes. And that this is influenced by our genes and ethnicity.

If your body stores fat in and around organs, such as the liver and pancreas, known as visceral fat, (rather than under the skin), this can cause insulin resistance. Some people call this 'hidden fat'.

This means your body’s cells don’t respond properly to the hormone insulin which helps keep blood sugar levels stable. So instead of keeping your blood sugar levels stable and within a healthy range, your blood sugar levels can rise.

If you are a healthy weight, you can still sometime have visceral fat. It can be indicated by a high waist measurement. Find out if your waist is a healthy size for your height, with the NHS waist to height ratio calculator.

Can I develop prediabetes if I’m a healthy weight?

You can develop prediabetes if you’re a healthy weight for your height and ethnicity. You can check which weight category you're in by using the NHS Body Mass Index, or BMI tool. 

This is because we know prediabetes is caused by many risk factors, including your age, ethnicity and family history.

Some people of a healthy weight, like some people living with overweight or obesity, may have more fat in and around their organs. See our information on prediabetes and body fat above.

If you've gained weight as you've got older but are still in the healthy weight range, it's thought this extra weight increases risk of prediabetes. This is known as your personal fat threshold. 

If you are underweight, losing more weight will not reduce your risk of getting type 2. It is important you see your GP for advice and support. You may be malnourished.

Can food and diet cause prediabetes?

In the same way as there are foods that can help you reduce your risk of type 2 diabetes, we know there is a link between having certain foods and drinks, and an increased risk of prediabetes. 

These include sugary drinks, refined carbs such as white bread, white rice and sugary breakfast cereals and red and processed meats like bacon, ham, sausages, pork, beef and lamb.

See which foods to limit or avoid and those to have more of in our healthy eating tips for prediabetes page. 

Can my living situation cause prediabetes?

We know inequalities significantly impact on the opportunities people have to lead a healthy life.

Living in a deprived community, being from a Black or Asian background, poor quality housing and being on a limited income can all play an indirect part in increasing your risk of prediabetes and type 2 diabetes.

Prediabetes may also follow a change in personal circumstances, such as a job loss, bereavement or having to take on caring responsibilities. This may impact on your ability to keep up healthy habits such as getting adequate sleep, eating well and finding the time and motivation to keep active.

How we can help

If you want a listening ear or have questions, call 0345 123 2399 and speak to one of our trained advisors. 

They have counselling skills and an extensive knowledge of diabetes. They can provide information on prediabetes and type 2 diabetes and type 2 prevention and take the time to talk things through and explore emotional, social, psychological or practical difficulties. 

You don't need a question about diabetes to call us. 

If you’d like to speak in a language other than English, if you provide your name, phone number, and preferred language. We’ll arrange for an interpreter to call you back within a few minutes.