Prediabetes is a warning zone: blood glucose is higher than it should be, but not high enough for a diabetes diagnosis. The good news is that, when detected early, the risk of progression to type 2 diabetes can be significantly reduced through weight loss, nutrition, exercise and medical monitoring.
This article is for information and does not replace a medical consultation. If your results are abnormal, discuss them with a doctor who can interpret them in your context: age, weight, treatments, family history and other health conditions.
Which levels define prediabetes?
According to criteria used in current clinical guidelines, prediabetes may be suggested by any of the following:
- HbA1c between 5.7% and 6.4%;
- fasting blood glucose between 100 and 125 mg/dL (5.6–6.9 mmol/L);
- blood glucose 2 hours into a glucose tolerance test between 140 and 199 mg/dL (7.8–11.0 mmol/L).
An isolated result needs confirmation and medical interpretation. Sometimes HbA1c and fasting glucose may tell different stories: for example, HbA1c can be affected by anaemia, blood disorders, pregnancy or certain treatments. To reach the correct diagnosis, the doctor may therefore recommend a combination of tests.
Who should be tested?
Testing is particularly important if you have overweight or obesity, an increased waist circumference, a family history of diabetes, high blood pressure, high triglycerides, low HDL, fatty liver or a history of gestational diabetes. Prediabetes is often linked to insulin resistance, and signs may be subtle or absent.
If you are over 45, even without clear symptoms, it is worth discussing regular testing with your doctor. If you are younger but have risk factors, testing may be indicated earlier.
Useful tests when assessing prediabetes
- HbA1c – shows average blood glucose over approximately the last 3 months. See the dedicated guide to glycated haemoglobin.
- Fasting blood glucose – a blood sample is taken after fasting, usually in the morning.
- Glucose tolerance test – useful when there is a suspicion but other tests are inconclusive.
- Lipid profile, blood pressure and waist circumference – help assess cardiometabolic risk and possible metabolic syndrome.
- ALT, AST, GGT – may guide assessment towards metabolic fatty liver disease, often associated with insulin resistance.
What can you do if you have prediabetes?
The interventions with the strongest evidence are sustained and measurable. Losing 5–7% of your starting weight and increasing physical activity to at least 150 minutes a week can significantly reduce the risk of type 2 diabetes in people at high risk.
In practice, this means consistent steps rather than an extreme diet:
- regular meals, with protein and fibre at each meal;
- reducing sweetened drinks and high-sugar sweets;
- choosing complex carbohydrates: pulses, wholegrains and vegetables;
- brisk walking or another moderate activity on most days;
- enough sleep and stress management, because both affect appetite and blood glucose.
A personalised nutrition plan is useful when you need clear examples, portions, shopping lists and adjustments to your actual schedule.
When do you need a consultation?
Arrange an assessment if your HbA1c is in the prediabetes range, your fasting glucose repeatedly exceeds 100 mg/dL or you have several risk factors. During an online diabetes consultation, the doctor can relate your tests to your history and recommend monitoring, nutrition or treatment where appropriate.
