How to Lower Glucose Levels: Diet, Lifestyle & Meds

How to lower glucose levels is a question that matters for millions of people across the UK, whether they have been diagnosed with diabetes, told they are at risk, or simply want to understand their blood sugar better. Raised blood glucose, if left unmanaged, can lead to serious long-term complications affecting the heart, kidneys, eyes, and nerves. The good news is that a combination of dietary changes, physical activity, and, where needed, medication can make a significant difference. This article explains what drives blood glucose up, what you can do about it, and when to seek medical advice.

What causes blood glucose levels to rise in the first place?

Blood glucose rises when insulin production or action is impaired, as in type 1 or type 2 diabetes, and can also spike due to refined carbohydrates, inactivity, stress, certain medicines, or hormonal changes. A fasting plasma glucose of 7.0 mmol/l or above confirms diabetes under NICE criteria.

Blood glucose levels rise when the body cannot produce enough insulin, cannot use insulin effectively, or both. Insulin is the hormone produced by the pancreas that allows cells to absorb glucose from the bloodstream and use it for energy. When this process is disrupted, glucose accumulates in the blood, a state known as hyperglycaemia.

In type 2 diabetes, the most common form in the UK, cells become resistant to insulin's effects over time. The pancreas initially compensates by producing more insulin, but eventually cannot keep pace with demand. In type 1 diabetes, the immune system destroys the insulin-producing beta cells of the pancreas, meaning little or no insulin is made at all.

Several factors can cause blood glucose to spike even in people without a diabetes diagnosis. These include:

• Eating foods high in refined carbohydrates or sugar, which are digested rapidly and flood the bloodstream with glucose

• Physical inactivity, which reduces the muscles' ability to take up glucose

• Stress and illness, which trigger the release of hormones such as cortisol and adrenaline that raise blood glucose

• Certain medicines, including corticosteroids and some antipsychotics

• Hormonal changes, such as those occurring during pregnancy (gestational diabetes) or the menstrual cycle

Understanding the underlying cause is important because it shapes the most appropriate management strategy. In UK practice, diabetes is typically confirmed using one of the following tests: a fasting plasma glucose of 7.0 mmol/l or above, an HbA1c of 48 mmol/mol (6.5%) or above, a random plasma glucose of 11.1 mmol/l or above in someone with symptoms, or an oral glucose tolerance test (OGTT) where the two-hour value is 11.1 mmol/l or above. An HbA1c of 42 to 47 mmol/mol (6.0 to 6.4%) indicates a high risk of developing type 2 diabetes (sometimes called prediabetes). These thresholds are set out in NICE guidance and NHS diagnostic criteria.

How can you lower your glucose levels through diet and lifestyle?

Choosing low-GI carbohydrates, increasing fibre, reducing free sugars, and achieving at least 150 minutes of moderate aerobic activity per week are the NICE-recommended first-line approaches to lowering blood glucose. A short walk after meals can also meaningfully reduce post-meal glucose rises.

Diet and lifestyle changes are the first-line approach recommended by NICE for managing raised blood glucose, and they can produce meaningful improvements even before any medication is needed. The core principle is reducing the speed and quantity of glucose entering the bloodstream while improving the body's sensitivity to insulin.

Dietary adjustments that evidence supports include:

• Choosing low glycaemic index (GI) carbohydrates such as wholegrains, legumes, and most vegetables rather than white bread, white rice, or sugary drinks

• Reducing portion sizes of starchy foods at each meal

• Increasing dietary fibre, which slows glucose absorption

• Limiting free sugars, including those in fruit juices, confectionery, and ultra-processed foods

• Spacing meals evenly through the day to avoid large glucose spikes

Physical activity is equally important. Muscle contraction allows cells to absorb glucose independently of insulin. The UK Chief Medical Officers' physical activity guidelines recommend adults aim for at least 150 minutes of moderate-intensity aerobic activity per week, alongside muscle-strengthening activity on two or more days.^[6][7] Even a short walk of 10 to 15 minutes after meals has been shown in research to help reduce post-meal glucose rises, and Diabetes UK includes this as practical advice for people managing blood sugar.^[23]

Important safety note for people on insulin or sulfonylureas: if you are taking insulin or a sulfonylurea (such as gliclazide), changes to your diet or activity levels can increase the risk of hypoglycaemia (low blood sugar). Speak to your GP, diabetes nurse, or pharmacist before making significant changes, ensure you are monitoring your glucose more frequently during any adjustment period, and always carry a fast-acting glucose source with you.

Weight management plays a significant role. Losing 5 to 10 per cent of body weight in people who are overweight can substantially improve insulin sensitivity and reduce HbA1c, as supported by NICE guidance on type 2 diabetes management.^[1][2] The NHS Type 2 Diabetes Path to Remission programme (formerly the Low Calorie Diet Programme) offers a structured, time-limited dietary intervention for eligible adults with a recent type 2 diabetes diagnosis and a BMI above a specified threshold.^[9] Evidence from the programme has demonstrated that structured weight loss can lead to remission in some people with early type 2 diabetes. Eligibility criteria and referral routes are available via NHS England.

Smoking cessation and reducing alcohol intake also support better glucose control, as both can impair insulin sensitivity and complicate diabetes management.

When should you speak to a GP about high blood sugar?

See a GP if you have persistent symptoms of hyperglycaemia such as increased thirst, frequent urination, or fatigue, or if home readings are consistently above your agreed target range. Seek emergency care via 999 or A&E immediately if DKA or HHS is suspected.

You should speak to a GP if you experience persistent symptoms of high blood sugar, particularly if they do not resolve with dietary changes. Classic symptoms of hyperglycaemia include increased thirst, frequent urination (especially at night), unexplained fatigue, blurred vision, and slow-healing cuts or infections. These symptoms warrant a blood test to check your glucose and HbA1c levels.

You should also contact your GP if:

• A home blood glucose reading is consistently above the target range agreed with your care team

• You have been told you have prediabetes and have not had a review in the past year

• You are pregnant or planning pregnancy and have concerns about blood sugar, as gestational diabetes requires prompt assessment

• You are taking a medicine known to raise blood glucose, such as a corticosteroid, and notice new symptoms

For people already diagnosed with diabetes, contact your GP or diabetes nurse if your glucose control has deteriorated despite following your current management plan, or if you are experiencing more frequent hypoglycaemic episodes alongside periods of high readings.

Seek emergency care via 999 or attend A&E immediately if you or someone else shows signs of diabetic ketoacidosis (DKA), which can include vomiting, abdominal pain, rapid breathing, confusion, or a fruity smell on the breath. DKA is a medical emergency most commonly associated with type 1 diabetes but can occur in type 2 diabetes under certain circumstances, including when taking SGLT-2 inhibitors.^[10][11]

People with type 2 diabetes, particularly older adults or those who are very unwell, may also be at risk of hyperosmolar hyperglycaemic state (HHS). Warning signs include severe thirst, very high blood glucose readings, signs of dehydration, drowsiness, and confusion. HHS is also a medical emergency requiring immediate care via 999 or A&E.

For urgent advice that does not require emergency attendance, NHS 111 is available 24 hours a day. Do not delay seeking help if you are unsure, as uncontrolled high blood glucose can cause serious complications over time.

What medicines does the NHS use to help lower blood glucose?

Metformin is the NICE-recommended first-line medicine for type 2 diabetes; SGLT-2 inhibitors, GLP-1 receptor agonists, DPP-4 inhibitors, sulfonylureas, and insulin may be added based on individual cardiovascular risk, kidney function, and tolerability. Type 1 diabetes is managed primarily with insulin replacement.

Several classes of medicine are recommended by NICE to help lower blood glucose in people with type 2 diabetes, and the choice depends on individual circumstances including kidney function, cardiovascular risk, weight, and tolerability. Medicines for type 1 diabetes centre on insulin replacement and are managed differently.

Metformin remains the first-line medicine for most people with type 2 diabetes, as recommended by NICE (NG28). It works primarily by reducing glucose production in the liver and improving insulin sensitivity. It is generally well tolerated, does not cause hypoglycaemia when used alone, and has a long safety record.

When additional glucose lowering is needed, NICE recommends considering:

• SGLT-2 inhibitors (such as dapagliflozin or empagliflozin), which cause the kidneys to excrete excess glucose in the urine. These also have cardiovascular and renal protective benefits and are recommended by NICE for people with established heart disease or chronic kidney disease. People taking SGLT-2 inhibitors should be aware of sick-day rules: during illness, dehydration, fasting, or surgery, these medicines should generally be paused and medical advice sought promptly, as there is a risk of DKA even when blood glucose is not markedly elevated.

• GLP-1 receptor agonists (such as semaglutide, available as Ozempic for type 2 diabetes management, or as Wegovy for chronic weight management at doses up to 2.4 mg weekly with a 7.2 mg maintenance option also licensed), which stimulate insulin release in response to meals and reduce appetite. Liraglutide is licensed for type 2 diabetes as Victoza; a separate higher-dose formulation, Saxenda, is licensed for weight management rather than glucose lowering.^[19][20] Tirzepatide (Mounjaro), a dual GIP and GLP-1 receptor agonist, is MHRA-authorised both for type 2 diabetes and for chronic weight management.^[13][14]

• DPP-4 inhibitors (such as sitagliptin), which enhance the body's own incretin response

• Sulfonylureas (such as gliclazide), which stimulate insulin release but carry a risk of hypoglycaemia^[12][22]

• Insulin therapy, used when other medicines are insufficient

Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online weight-management consultations, with prescriber review and pharmacist support, where clinicians can assess which treatment, if any, may be appropriate for an individual. Mounjaro is one option a prescriber may consider following an online consultation with Bolt Pharmacy, and is only prescribed where clinically appropriate. All medicines should be prescribed and monitored by a qualified clinician, and any suspected side effects can be reported to the MHRA via the Yellow Card scheme at yellowcard.mhra.gov.uk.

Scientific References

1. Type 2 diabetes in adults: management (NG28).
2. Type 2 diabetes in adults: management (NG28) – full guideline PDF.
3. Type 2 diabetes in adults: choosing, reviewing and stopping medicines – visual summary (NG28).
4. Type 2 diabetes: prevention in people at high risk (PH38).
5. High blood sugar (hyperglycaemia).
6. Physical activity guidelines: UK Chief Medical Officers' report.
7. UK Chief Medical Officers' physical activity guidelines (full text).
8. Physical activity guidelines for adults aged 19 to 64.
9. Early findings from the NHS Type 2 Diabetes Path to Remission programme.
10. SGLT2 inhibitors: updated advice on the risk of diabetic ketoacidosis.
11. Empagliflozin 10 mg film-coated tablets – SGLT2 inhibitors: advice on the risk of diabetic ketoacidosis.
12. Type 2 diabetes – treatment summary.
13. Tirzepatide.
14. MHRA authorises diabetes drug Mounjaro (tirzepatide) for weight management and weight loss.
15. Tirzepatide.
16. Semaglutide.
17. Medicines regulator approves up to 7.2 mg dose of semaglutide (Wegovy) for patients with obesity.
18. Single-dose 7.2 mg semaglutide (Wegovy) pen approved to treat adult patients with obesity.
19. Liraglutide.
20. Liraglutide: a medicine to treat type 2 diabetes or obesity.
21. GLP-1 medicines for weight loss and diabetes: what you need to know.
22. Gliclazide 40 mg Tablets.
23. Effects of short-bout accumulated exercise on postprandial metabolism in adults: A systematic review and meta-analysis.

Frequently Asked Questions