In short: your body keeps blood glucose in a narrow range with insulin. When cells respond poorly to insulin, glucose rises, first to prediabetes, then often to type 2 diabetes. Large trials show that losing a little weight, moving more and eating well cut the risk of progressing by more than half.
At a glance
| Key hormone | Insulin lowers blood glucose; glucagon raises it |
|---|---|
| Fasting glucose (WHO) | Normal below 6.1 mmol/L (110 mg/dL); diabetes from 7.0 mmol/L (126 mg/dL) |
| HbA1c | Diabetes from 48 mmol/mol (6.5%); ranges for prediabetes differ by guideline |
| Main risk factors | Excess weight around the waist, inactivity, family history, age, past gestational diabetes |
| What prevents it | About 5–7% weight loss, 150 minutes of activity a week, more fibre, good sleep |
Know your numbers
Fasting glucose and HbA1c show where you stand.
Move after meals
Muscles take up glucose when they work.
Results over time
Keep every glucose and HbA1c result in the app, in either unit.
How does the body control blood sugar?
After a meal, carbohydrates are broken down into glucose, which enters the blood. The pancreas releases insulin, which lets muscle, liver and fat cells take glucose in. Between meals and overnight, glucagon tells the liver to release stored glucose. This keeps blood glucose in a narrow range all day.
What are prediabetes and type 2 diabetes?
In insulin resistance, cells respond less to insulin, so the pancreas makes more. When it can no longer keep up, glucose rises. Prediabetes means levels are above normal but below the diabetes threshold; type 2 diabetes means they are high enough to damage blood vessels, nerves, eyes and kidneys over time. Many people with either have no symptoms, which is why testing matters.
What do the numbers on a report mean?
Fasting glucose measures glucose after at least 8 hours without food; HbA1c reflects the average over about three months. WHO defines diabetes as fasting glucose of 7.0 mmol/L (126 mg/dL) or more, or HbA1c of 48 mmol/mol (6.5%) or more, confirmed by a repeat test. Thresholds for prediabetes differ between WHO, ADA and national guidelines. Your doctor interprets your own results.
Who is at risk?
Risk rises with excess weight, especially around the waist, physical inactivity, a parent or sibling with type 2 diabetes, age over 40–45, past diabetes in pregnancy, high blood pressure and some ethnic backgrounds, including South Asian, African and Caribbean. Polycystic ovary syndrome and short sleep also raise risk. Ask your doctor about testing if several apply.
What actually prevents type 2 diabetes?
The US Diabetes Prevention Program and the Finnish Diabetes Prevention Study showed that losing 5–7% of body weight and doing about 150 minutes of moderate activity a week reduced progression from prediabetes to diabetes by about 58%. Helpful habits:
- Choose whole grains, legumes, vegetables and fruit over refined carbohydrates.
- Swap sugary drinks for water.
- Break up long sitting; a short walk after meals lowers glucose peaks.
- Sleep at least 7 hours and stop smoking.
Any treatment decision, including medicines, is for your doctor.
Key terms
- Glucose: the main sugar in the blood and a key fuel for cells.
- Insulin: a hormone from the pancreas that lets cells take up glucose.
- Insulin resistance: when cells respond less to insulin.
- HbA1c: the share of haemoglobin with glucose attached, reflecting about three months of glucose levels.
- Prediabetes: glucose above normal but below the threshold for diabetes.
Sources
- WHO: Diabetes fact sheet
- Knowler et al., Diabetes Prevention Program, NEJM (2002)
- NIDDK: Insulin resistance and prediabetes
- CDC: Prediabetes
- Tuomilehto J et al. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance (Finnish Diabetes Prevention Study). N Engl J Med 2001
Frequently asked questions
What is a normal blood sugar level?
In WHO terms, a fasting glucose below 6.1 mmol/L (110 mg/dL) is normal. Values after meals are higher. Laboratories print their own reference range, and your doctor interprets results in context.
Can prediabetes be reversed?
In many people, yes. Weight loss, regular activity and better food can bring glucose back to the normal range. It needs ongoing habits, not a short diet.
Does eating sugar cause diabetes?
Not directly, but diets high in sugary drinks and refined carbohydrates promote weight gain and are linked to higher risk. Overall diet and weight matter most.
Do I need a glucose monitor if I don't have diabetes?
Continuous glucose monitors are designed for people with diabetes. For others, the value of tracking is unproven; a blood test with your doctor is the standard check.
What are early signs of diabetes?
Often none. Some people notice thirst, passing urine often, tiredness, blurred vision or slow-healing cuts. See a doctor if you have these.
How often should I be tested?
It depends on your age and risk factors and on national guidance. Ask your doctor; many recommend testing every one to three years for people at higher risk.
Try it in Anpheros Daily
Note how you sleep, eat, feel and move in Anpheros Daily, next to your lab results, and see the patterns over weeks.
Anpheros builds a medical record that the patient controls and can share with any clinic, on an HL7 FHIR R4 platform, based in the EU. These guides help you understand and organise your health; they do not replace your doctor.
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