Prediabetes

Blood sugar that’s higher than normal but not high enough to be diabetes. About 1 in 3 people with prediabetes develop type 2 diabetes within 10 years. The good news: modest weight loss and more movement can roughly halve that risk.

Symptoms

• Usually none. It’s found on a blood test, often during a check-up.
• If you have thirst, frequent urination or repeated infections, get tested for diabetes itself.

Causes and risk factors

• The same things that lead to type 2 diabetes: family history, getting older, extra weight around the waist and not moving much.
• Diabetes in a past pregnancy, or polycystic ovary syndrome (PCOS).
• Higher rates in some communities, including Aboriginal and Torres Strait Islander, Pacific Islander and South Asian people.

How it’s diagnosed

• HbA1c (3-month sugar average) of 6.0–6.4%.
• Or a fasting glucose of 6.1–6.9 mmol/L (impaired fasting glucose).
• Or a 2-hour result of 7.8–11.0 mmol/L on a glucose tolerance test (impaired glucose tolerance).
• In Australia, the AUSDRISK questionnaire estimates your 5-year diabetes risk; a high score means it’s time for a blood test.
• Once you know you have prediabetes, recheck HbA1c every year.

The prediabetes ladder

Lifestyle change is the main treatment and beats tablets in trials. Medicines are an add-on for some people, not a shortcut.

1. Step 1 · Self-careLose 5–10% of your weight and move moreAim for 150–300 minutes a week of moderate activity plus some strength work, and sit less. For a 90 kg person, 5–10% is 4.5–9 kg.

   Works

   Losing 5–10% of body weight halves the risk of developing type 2 diabetes

   Cost

   Free

   How long

   Ongoing

   Watch for

   Crash diets rebound. Slow and sustainable wins.

   You don’t need a new body. You need about 5% less of the current one.

2. Step 2 · ProgramA structured lifestyle programGroup or online coaching on food, activity and habits over months, often with a health coach or dietitian.

   Works

   In the US Diabetes Prevention Program, intensive lifestyle coaching cut new diabetes by 58% over about 3 years

   Cost

   Some programs are free or subsidised; costs vary; dietitian visits rebated with a GP care plan

   How long

   Usually 6–12 months

   Watch for

   Ask your GP what’s available locally; options differ by state and country.

   Accountability is the secret ingredient. Turns out we behave better when someone checks.

3. Step 3 · PrescriptionMetforminA diabetes tablet sometimes used to prevent diabetes in people at highest risk (off-label in Australia).

   Works

   Cut new diabetes by 31% in the same trial: helpful, but less than lifestyle change

   Cost

   Under the $25 PBS co-payment; $7.70 concession

   How long

   Long term, with yearly checks

   Watch for

   Nausea and diarrhoea; take with food. Low B12 over years.

   The understudy. Good, but lifestyle is still the lead.

4. Step 4 · PrescriptionWeight-loss medicines (GLP-1 medicines)Weekly injections that reduce appetite, for people with obesity or extra weight plus a related condition.

   Works

   Average weight loss of about 8–15% or more over 1 to 1.5 years, depending on the medicine; weight loss lowers diabetes risk

   Cost

   Not on the PBS for weight loss, so full private price

   How long

   Long term; weight usually returns after stopping

   Watch for

   Nausea, vomiting, constipation, gallstones.

   A helpful tool for some, not a substitute for the basics.

5. Step 5 · SpecialistWeight-loss (bariatric) surgeryFor people with severe obesity, after other approaches.

   Works

   Prevents progression to diabetes better than usual care in studies

   Cost

   Free in the public system (long waits); private costs often run to thousands

   How long

   One operation, lifelong follow-up

   Watch for

   Needs lifelong vitamin supplements and follow-up.

   A big intervention for a big problem. Not the first rung.

Costs are rough Australian prices in November 2026 and vary by pharmacy and provider. PBS co-payment: $25, or $7.70 with a concession card. Results are typical figures from trials, not promises.

Save your money

Popular, heavily marketed or often asked about, but the evidence is weak or says no.

• Home fingerprick testingNot recommended for prediabetes: sugar rarely goes too low, and a yearly HbA1c tells you more. Save the strips.
• Blood-sugar “balancing” supplementsNo supplement or tablet is approved to prevent diabetes. Walking is free and has the trials.
• Waiting to see what happensAbout a third progress within 10 years. The window to change course is now.

What you can do

• Pick one change you can keep: a daily walk, water instead of soft drink, smaller portions.
• Ask your GP about a structured lifestyle program near you.
• Recheck HbA1c every year, and know your blood pressure and cholesterol too: prediabetes raises heart risk.
• Sleep counts: poor sleep makes weight and sugar harder to manage. See trouble sleeping.
• If you smoke, quitting helps your heart and your sugar.

See your GP if

• You score high on the AUSDRISK test
• You had diabetes in pregnancy, or have PCOS and haven’t had a sugar test lately
• Your HbA1c hasn’t been rechecked in over a year
• You have symptoms such as thirst, frequent urination or repeated infections

See a doctor promptly if you’re very thirsty, passing lots of urine, losing weight without trying, or feeling very unwell: that may be diabetes rather than prediabetes.

Helpful resources

• AUSDRISK diabetes risk testShort questionnaire that estimates your 5-year chance of type 2 diabetes. Free, Australian Government.
• Healthier You: NHS Diabetes Prevention ProgrammeThe national lifestyle program for adults in England at risk of type 2 diabetes. UK.

Evidence and more information

• Australian Diabetes Society: Prediabetes position statement (summary)
• Diabetes Prevention Program results (NIH)
• Diabetes Prevention Program: Lifestyle or metformin for prediabetes (NEJM, 2002)
• Diabetes Victoria: Diagnosis of diabetes
• NDSS: Registration and eligibility
• STEP 1 trial: Semaglutide for weight management (NEJM)

Reviewed 1 November 2026. General education, not personal medical advice. Treatment depends on your situation, so talk to your GP or pharmacist.

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