Prediabetes | Tūraru mate huka

Also called borderline diabetes

Prediabetes (tūraru mate huka) is when the amount of glucose (sugar) in your blood is higher than normal but is not high enough to be diabetes yet. This means you are at much higher risk of getting type 2 diabetes and heart disease.

On this page, you can find the following information:

Finding out whether you have prediabetes can be an opportunity to make changes and stop it progressing to type 2 diabetes and increasing your risk of heart disease. 

The best things you can do to prevent prediabetes or delay it progressing to diabetes are to maintain a healthy body weight, make healthy food and drink choices and have regular physical activity.

Image credit: Canva

What is prediabetes?

Prediabetes occurs when the amount of glucose (sugar) in your blood is higher than normal but is not high enough to be diabetes yet. Prediabetes is a warning sign that type 2 diabetes, which affects 1 in 5 New Zealand adults, might be in your future. 

Is having prediabetes a concern?

Yes, having prediabetes is a concern because people with prediabetes have higher blood sugar than normal. This puts them at higher risk of developing type 2 diabetes and heart disease. However, if you follow a healthy lifestyle at this stage, you have a chance to delay or prevent type 2 diabetes developing.

What are the causes of prediabetes?

Insulin is the hormone that usually controls your blood glucose, keeping it in the healthy range. Prediabetes is an indicator that your body is beginning to stop using insulin as efficiently as it should. In other words, your body is starting to become resistant to insulin. When your body resists insulin, the glucose levels in your blood rise, which is how you develop prediabetes and, if that process is not stopped and allowed to progress, type 2 diabetes. Being overweight and eating an unhealthy diet increases your risk of becoming resistant to insulin.    

What are the symptoms of prediabetes?

Not everyone with prediabetes has symptoms. Early signs of prediabetes can include:

  • increased thirst
  • increased hunger
  • needing to urinate (pee) often
  • feeling very tired. 

If you have noticed some or all of these symptoms, visit your doctor for a blood glucose check.

How is prediabetes diagnosed?

There are a few blood tests that can diagnose prediabetes. The most common test is called HbA1c, which measure the amount of glucose that has built up in your blood over a 3-month period. Other tests include a fasting blood glucose and a glucose tolerance test. Read more about how is diabetes and prediabetes diagnosed.   

Who should be tested for prediabetes?

The age at which you should be tested for prediabetes depends on your ethnicity, family history and other medical history. This is because diabetes is more common in Māori, Pasifika and Asian ethnicities, people who are overweight,  people who have whānau/family members with diabetes. Read more about who should be screened for diabetes.  

How is prediabetes treated?

People with prediabetes are also at increased risk of developing diabetes complications, so it needs to be treated. Read more about complications of diabetes.

Prediabetes is treated mainly by changing your lifestyle where needed. This could delay you developing diabetes by 3–4 years or even prevent you developing it. Healthy lifestyles are made up of healthy eating, active living, a healthy body weight and being smoke free.

Other treatment of prediabetes can also include:

If you have prediabetes, it is also important to have an HbA1c test every year to check whether you have progressed to type 2 diabetes.

Lifestyle management

Healthy eating

  • There is no special diabetes diet. Like everyone, you can follow Michael Pollan's advice to “Eat food. Not too much. Mostly plants”.
  • Healthy eating is not about sticking to strict diets or depriving yourself of the foods you love. 
  • Instead, eat a wide range of different foods, mostly plant-based and less processed, that help you feel great, have more energy, improve your outlook and achieve or maintain a healthy weight.
  • Find out more healthy eating basics and advice from the New Zealand Society for the Study of Diabetes on healthy eating.

Active living

  • Regular physical activity, sitting less and moving more can help you have a healthy body weight, feel more positive and lower your risk of diabetes, heart disease and some cancers.
  • Physical activity also helps your body to use insulin properly.
  • Try not to sit down for longer than 30 minutes at a time.
  • Aim to be active for at least 30 minutes every day, increasing to 60 minutes daily if you want to reduce your body weight.
  • A good intensity level is to feel heart rate go up and heavier breathing, but still able to speak a sentence.
  • Include some resistance exercise at least twice a week.
  • Doing some physical activity is still better than doing none.
  • Make sure you wear comfortable, supportive and well-fitting shoes as you are at greater risk of foot problems if you have prediabetes or diabetes. 
  • If you find it hard to start or maintain an exercise routine, talk to your doctor as you may be able to get a green prescription to access support.
  • Find out more about physical activity.

A healthy body weight

  • If you have overweight or obesity, losing 5–10% of your initial body weight can significantly improve your blood glucose, blood pressure and cholesterol.
  • Making good choices about what you eat and drink, and being physically active, are important to achieve and keep a healthy body weight.
  • For every 1 kilogram of weight you lose, your risk of diabetes could reduce by 16%.

Be smoke free

If you are a smoker, quitting smoking is also important.


If you drink alcohol, try to reduce your intake as it contains a lot of calories and can make weight management more difficult. Regular heavy drinking can reduce the body’s sensitivity to insulin, which can trigger type 2 diabetes.

How is prediabetes prevented?

The best things you can do to prevent prediabetes are:

What support is available with prediabetes?

Diabetes support groups Diabetes self-management support (6–8 hours over 1 day or for 3–4 consecutive weeks) is available in some areas. Ask your GP or practice nurse about what’s available in your area.

Learn more

The following links provide further information about prediabetes. Be aware that websites from other countries may have information that differs from New Zealand recommendations. 

Prediabetes Diabetes NZ Auckland Branch
Prediabetes HealthInfo Canterbury, NZ
JumpStart Exercise, nutrition and support programme for people with diabetes and prediabetes
Diabetes NZ


  1. Prediabetes Ministry of Health, NZ & NZ Society for the Study of Diabetes, 2020
  2. Prediabetes – risk factor management Ministry of Health, NZ, 2016
  3. HbA1c testing Health Navigator NZ

Reviewed by

Julie Carter works as a liaison dietitian for the Auckland District Health Board. She has an interest in public health nutrition.
Credits: Health Navigator Editorial Team. Reviewed By: ADHB community liaison dietitian Julie Carter Last reviewed: 01 May 2018