Last updated August 2026
What the numbers are now
The test is HbA1c, which measures your average blood glucose over roughly the previous three months. It is a single blood test, usually done alongside whatever else your GP is checking.
★View the Best Health Coaches in Hastings→Under the current New Zealand criteria:
- 40 to 41 mmol/mol is considered normal
- 42 to 47 mmol/mol is prediabetes
- 48 mmol/mol and above indicates diabetes
The diabetes threshold came down from 50, and the prediabetes band narrowed from the old 41 to 49 range. Diabetes New Zealand has published the detail of what changed and why, and Healthify explains what the test itself actually measures.
Why it changed, and who it affects
The change brings New Zealand into line with World Health Organisation criteria. The intention is to catch type 2 diabetes earlier, when there is more that can be done about it, and to reduce the disparities that come from diagnosing some groups later than others.
The practical effect cuts two ways. Around 34,500 more people in New Zealand now meet the criteria for diabetes at a number that previously would have been called prediabetes. At the same time, roughly 200,000 people who were told they had prediabetes no longer meet the definition, because the lower end of the band moved up.
So an old result deserves a second look rather than an assumption. A 41 that worried you a year ago is now inside the normal range. A 48 that was previously “prediabetes, keep an eye on it” is now a diabetes diagnosis.
What prediabetes actually means
It means your blood glucose is higher than it should be but not yet high enough to be called diabetes. It is not a mild version of diabetes and it is not a certainty of getting it.
It is a signal that insulin is not working as efficiently as it used to. Your body still manages, but it is working harder to do so, and the trend usually continues in the same direction unless something changes.
The important part, and the reason it is worth knowing about at all: this is the stage where change makes the most difference. The New Zealand Society for the Study of Diabetes sets out the clinical guidance, and the consistent finding across the research is that sustained changes to eating and activity at this point meaningfully alter what happens next.
It usually has no symptoms
This is the part that catches people out. Prediabetes generally feels like nothing at all.
Some people notice things in hindsight, an afternoon energy dip, waking unrefreshed, weight creeping on around the middle despite no obvious change in habits. But those are vague enough to be attributed to being busy, or to being in your forties, and most people do exactly that.
Which means the only reliable way to know is a blood test. If you are over forty, carrying weight around the middle, have a family history of type 2 diabetes, or are of Māori, Pasifika or South Asian descent, that is a conversation worth having with your GP rather than waiting for a symptom that may never arrive.
What actually moves the number
Four things, in roughly the order of how much difference they tend to make.
What you eat, and when. The quantity and type of carbohydrate has the most direct effect on blood glucose. So does the spacing of meals, because constant grazing means insulin never gets a break.
Muscle. Skeletal muscle is where most glucose gets used. Resistance training two or three times a week improves how your body handles carbohydrate, and it does so at any age.
Sleep. Poor sleep affects glucose regulation the following day and pushes appetite toward quick energy foods. It is unglamorous and it matters.
Weight, particularly around the middle. Not because of appearance, but because visceral fat is metabolically active and is closely tied to insulin resistance.
None of that is a secret and none of it is quick. The people who change the number are the ones who change the habits rather than the ones who try hardest for six weeks.
The Hawke’s Bay complication
There is a local version of this worth naming. Hawke’s Bay grows an enormous amount of very good fruit, and from December through to autumn it is everywhere, cheap and excellent.
Whole fruit is not the problem it gets made out to be, and stripping it out of your diet is rarely the right answer. But quantity matters, and it is easy to eat a great deal more of it here than you would anywhere else in the country without ever registering that you are doing it. Juice is a different thing again, and behaves nothing like the fruit it came from.
The point is not to avoid the good part of living here. It is to know that a summer in Hawke’s Bay is not a neutral background when you are trying to shift a number.
What to do if yours has moved
Start with your GP. Ask what your last HbA1c was, what it is under the current criteria, and whether it is worth retesting. If you have not had one and you fit the risk profile above, ask for one.
If the result puts you in the prediabetes band, that is information rather than a verdict, and the response is a plan rather than a prescription. If it puts you at 48 or above, that is a diagnosis and it belongs firmly with your doctor.
What almost nobody needs is another six week diet.
Where Ingrid Milnes fits
Knowing the number is straightforward. Changing it is where people get stuck, usually because the advice they are given is correct but general, and because the eating patterns that move blood glucose are not the ones most diets are built around.
Ingrid Milnes is a certified metabolic health coach with a degree in psychology, working with adults at midlife and beyond, in person across Hawke’s Bay and online elsewhere in New Zealand. The focus is specifically metabolic: how and when you eat, blood sugar regulation, movement after 40 and sleep, rather than weight in isolation. She is a coach rather than a clinician, so this sits alongside your GP rather than instead of them.
Her programmes run as an eight week one on one at $580, or as a small group of six to eight over Zoom at $349, with an optional continuous glucose monitor for people who would rather see how their own body responds than take anyone’s word for it. The programmes and pricing are listed on her site, along with a plain English explainer of what metabolic health actually means. She offers a free fifteen minute call first, which is the sensible place to find out whether any of it applies to you.
