Preventing Type 2 Diabetes

How to understand your risk and make changes that may prevent or delay diabetes

Type 2 diabetes often develops gradually.

Many people feel well while their blood glucose is slowly rising. By the time symptoms appear, diabetes may already be established.

The encouraging news is that type 2 diabetes is not inevitable for everyone at increased risk. Improving eating patterns, becoming more active, managing weight where appropriate and addressing other risk factors can substantially reduce or delay its development. Diabetes Australia advises that lifestyle changes may prevent or delay type 2 diabetes in many people at high risk.

Prevention does not require perfection. It starts with understanding your risk and choosing changes you can maintain.

What is type 2 diabetes?

Glucose is an important source of energy. The hormone insulin helps glucose move from your bloodstream into your cells.

In type 2 diabetes, the body becomes less responsive to insulin and may eventually be unable to produce enough insulin to keep blood glucose within a healthy range.

Persistently high blood glucose can damage blood vessels and nerves. Over time, type 2 diabetes can increase the risk of:

• Heart attack and stroke
• Kidney disease
• Vision loss
• Nerve damage
• Foot problems
• Delayed healing and infection

Type 2 diabetes is different from type 1 diabetes, which is an autoimmune condition and cannot currently be prevented.

What is prediabetes?

Prediabetes means blood glucose is higher than the healthy range but not yet high enough to meet the diagnostic criteria for diabetes.

It usually causes no symptoms.

Prediabetes is important because it signals an increased risk of developing type 2 diabetes and cardiovascular disease. It is also an opportunity to act before diabetes develops. Lifestyle changes can sometimes return blood glucose to a healthier range or prevent progression for many years.

Prediabetes does not mean diabetes is certain. It means your risk is higher and deserves attention.

Who is at increased risk?

Some risk factors cannot be changed. Others can be reduced or managed.

Your risk may be higher if you:

• Are getting older
• Have a parent, brother or sister with diabetes
• Are Aboriginal or Torres Strait Islander
• Have Pacific Islander, Māori, Asian, Middle Eastern, North African or Southern European heritage
• Have previously had high blood glucose
• Had gestational diabetes
• Have polycystic ovary syndrome
• Take medicine for high blood pressure
• Have excess weight, particularly around the waist
• Are physically inactive
• Smoke
• Have cardiovascular disease
• Have obstructive sleep apnoea

No single factor proves that you will develop diabetes. Risk factors combine, and their importance varies between individuals.

Check your risk with AUSDRISK

The Australian Type 2 Diabetes Risk Assessment Tool, known as AUSDRISK, estimates your chance of developing type 2 diabetes within the next five years.

It asks about factors including:

• Age
• Sex
• Cultural background
• Family history
• Previous high blood glucose
• Blood-pressure treatment
• Smoking
• Fruit and vegetable intake
• Physical activity
• Waist circumference

A score of:

• 5 or less indicates low five-year risk
• 6–11 indicates intermediate risk
• 12 or more indicates high risk or possible undiagnosed diabetes

AUSDRISK is a screening tool, not a diagnosis. A high score should lead to a discussion with your GP and usually a blood test.

How is diabetes risk checked?

Your GP may assess your risk using AUSDRISK, your medical and family history, physical measurements and blood tests.

Common tests include:

HbA1c

HbA1c estimates your average blood glucose over the previous two to three months.

It does not usually require fasting.

Fasting blood glucose

This measures blood glucose after fasting, usually overnight.

Oral glucose tolerance test

This measures how your body handles a standard glucose drink. It may be used when other results are uncertain, during pregnancy or when gestational diabetes is being assessed.

One abnormal result may need confirmation unless symptoms and blood glucose are clearly diagnostic. Your GP will interpret the result in context rather than relying on a home glucose meter or wearable sensor alone.

Eat in a way that supports metabolic health

There is no single “diabetes prevention diet”.

A useful eating pattern generally includes:

• Plenty of vegetables
• Whole fruit rather than juice
• Legumes such as beans, lentils and chickpeas
• Mostly wholegrain or high-fibre carbohydrates
• Fish, eggs, tofu, lean meat, poultry or other protein sources
• Nuts, seeds, avocado and unsaturated oils
• Water as the main drink

Try to reduce frequent intake of:

• Sugary drinks
• Highly refined snack foods
• Large portions of discretionary foods
• Processed meats
• Excess alcohol

Carbohydrate foods do not all need to be removed. Quality, quantity and what you eat with them matter.

Wholegrains, legumes and minimally processed foods generally provide more fibre and produce a steadier rise in blood glucose than sugary drinks, confectionery and highly refined foods.

Move more and build muscle

Physical activity helps muscles use glucose and improves the body’s response to insulin.

It may also improve blood pressure, cholesterol, sleep, mood and weight management.

Aim to build towards:

• At least 30 minutes of moderate activity on most days
• Strength exercise on at least two days each week
• More light movement throughout the day
• Regular breaks from prolonged sitting

Walking, cycling, swimming, dancing, gardening and active household tasks can all help. Resistance bands, body-weight exercises and weights can build muscle.

You do not need to reach the full target immediately. Starting with a ten-minute walk and increasing gradually is worthwhile.

Weight loss can help — but it is not the only goal

For people carrying excess weight, particularly around the waist, modest weight loss can significantly reduce the risk of developing type 2 diabetes.

You do not need to reach an “ideal” BMI before gaining benefit. A reduction of around 5–10% of starting weight may improve insulin sensitivity, blood pressure and blood glucose.

Weight loss is not appropriate for everyone. People who are underweight, frail, pregnant or living with an eating disorder require a different approach.

Even when weight changes little, better food quality, increased movement and improved fitness remain valuable.

Sleep, stress and smoking also matter

Poor sleep and untreated obstructive sleep apnoea can make metabolic health harder to manage.

Stress can affect appetite, sleep, activity and the ability to maintain routines. It may also influence blood glucose through hormonal pathways.

Smoking increases cardiovascular risk and is included in the AUSDRISK assessment. Stopping smoking is one of the most valuable steps for long-term health, regardless of whether weight temporarily changes afterwards.

What if you had gestational diabetes?

Gestational diabetes increases the future risk of type 2 diabetes.

Blood glucose should be reassessed after pregnancy and then monitored regularly. Annual screening is often recommended for people with a history of gestational diabetes.

The months after pregnancy can be demanding, and lifestyle changes may need to be gradual. Breastfeeding, sleep disruption, mental health, family support and future pregnancy plans should all be considered.

Can medicine prevent type 2 diabetes?

Lifestyle support remains the foundation of prevention.

For some people at particularly high risk, a GP may consider medicine such as metformin. This is an individual decision based on blood glucose, age, weight, medical history, pregnancy plans and the likelihood of benefit.

Weight-management medicines may also reduce diabetes risk in selected people living with overweight or obesity, but they are prescription treatments with potential adverse effects, contraindications and costs.

Medicine should not be started solely on the basis of an online risk score, and products from unregulated websites or social media may be counterfeit or unsafe.

How often should you be screened?

The appropriate interval depends on your risk.

Screening may be considered:

• Around every three years from age 40 when risk is present
• Every one to two years for people with prediabetes or multiple risk factors
• Every year for Aboriginal and Torres Strait Islander adults
• Every year after gestational diabetes

Your GP may recommend a different interval based on previous results and your individual circumstances.

Seek earlier assessment if you develop symptoms such as:

• Excessive thirst
• Frequent urination
• Unexplained weight loss
• Blurred vision
• Recurrent infections
• Marked tiredness

These symptoms are not specific to diabetes but deserve medical review.

Start with one change

Choose one action you can repeat:

• Complete the AUSDRISK questionnaire
• Book a GP check if your score is high
• Replace sugary drinks with water
• Walk for ten minutes after a regular meal
• Add vegetables to lunch or dinner
• Begin two short strength sessions each week
• Arrange help to stop smoking
• Ask whether you are due for an HbA1c or fasting glucose test

Small actions become powerful when they are sustained.

The bottom line

Type 2 diabetes develops through a combination of genetics, age, biology, lifestyle and environment. It is not simply the result of poor choices.

Many people can substantially reduce or delay their risk through regular movement, nourishing food, weight management where appropriate, better sleep, smoking cessation and regular health checks.

Use AUSDRISK to understand your five-year risk, but do not rely on the score alone. A GP assessment and blood tests can identify prediabetes or diabetes before symptoms appear.

Acting early gives you more options — and small, realistic changes can make a meaningful difference.