Prediabetes | Tūraru mate huka

Also called impaired glucose tolerance

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. 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:

  • maintain a healthy body weight
  • make healthy food and drink choices
  • 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. About 20% of the adult population is likely to have prediabetes.

Is having prediabetes a concern?

Yes, it is a concern because if you have prediabetes you have higher blood glucose levels than normal. This puts you at higher risk of developing type 2 diabetes and heart disease. However, following a healthy lifestyle is a very powerful way to prevent or delay type 2 diabetes developing.

What are the causes of prediabetes?

Insulin is the hormone your body produces to control the glucose in your blood, keeping it in the healthy range. Prediabetes is an indicator that your body isn't using insulin as well 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. If that process is not stopped and is allowed to progress, you will develop 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/mimi) often
  • feeling very tired. 

If you have noticed some or all of these symptoms, or have any of the risk factors for diabetes, visit your healthcare provider 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 diabetes and prediabetes are 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 South Asian (eg, Indian, Pakistani, Sri Lankan) ethnicities, people who are overweight and people who have whānau 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 at all. Healthy lifestyles are made up of healthy eating, active living, having a healthy body weight and being smoke free.

Other treatments for prediabetes can include:

  • Diabetes medicine – if lifestyle changes don’t lead to your blood glucose levels reducing enough, your healthcare provider may consider prescribing metformin.
  • Treating other cardiovascular risk factors such as high blood pressure and high blood fats (eg, cholesterol).

If you have prediabetes, it's 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 prediabetes 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 really 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 your heart rate go up and experience heavier breathing, but still be 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 healthcare provider 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 are overweight or obese, losing 5–10% of your initial body weight can significantly improve your blood glucose, reduce your risk of developing diabetes, and reduce your blood pressure and cholesterol.
  • Making good choices about what you eat and drink, and being physically active will help you achieve and keep a healthy body weight.

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 also make your body resist 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 for prediabetes?

Diabetes support groups Diabetes self-management support groups or programmes are available in some areas. Ask your healthcare provider 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
  4. Endoscopic weight loss program John Hopkins Medicine, US 
Credits: Health Navigator Editorial Team. Reviewed By: Associate Professor Sue Wells, Public Health Physician, University of Auckland Last reviewed: 05 Dec 2022