The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
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Waist Measure: NHS UK Guidance
Your waist measurement is an important health indicator that the NHS recommends monitoring alongside your weight and BMI. Unlike BMI alone, waist circumference directly reflects abdominal fat, which carries greater health risks. This UK health guide explains NHS waist measurement thresholds, why your GP recommends checking it, and how to measure accurately for your health.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
NHS Waist Measurement Thresholds for UK Adults
The NHS and NICE recommend monitoring waist circumference as a key health marker. For UK adults, healthy waist limits vary by sex and ethnicity:
- Men: Below 94cm (37 inches) = low health risk; 94–102cm = increased risk; above 102cm (40 inches) = high risk
- Women: Below 80cm (31.5 inches) = low health risk; 80–88cm = increased risk; above 88cm (34.5 inches) = high risk
- South Asian, Chinese, Black African, and Black Caribbean adults: Lower thresholds apply — 90cm for men and 80cm for women indicate increased risk due to higher cardiovascular disease risk in these populations at lower waist circumferences
Waist measurement is particularly valuable because it identifies people with central obesity — excess fat around the organs — which poses greater health risks than fat stored elsewhere. Your GP may ask about your waist measurement during health checks, especially if your BMI falls in the overweight or obese range.
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How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
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How to Measure Your Waist Accurately
Accurate waist measurement requires the right technique. Stand with your feet hip-width apart and wear no heavy clothing or belts. Using a soft measuring tape, find the midpoint between your lowest rib and your hip bone. Wrap the tape loosely around your waist — it should sit flat but not compress your skin. Breathe normally and read the measurement at the end of a natural breath out. Measure twice to ensure accuracy.
Track your waist measurement regularly as part of your overall health monitoring. Combined with your BMI and weight, waist circumference gives a fuller picture of your health risk. Use our free BMI calculator alongside your waist measurement to understand your complete health profile, and discuss results with your GP for personalised health guidance.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
Why is waist measurement important if I already know my BMI?
BMI doesn't distinguish between muscle and fat, or show where fat is stored. Waist measurement identifies central obesity — excess abdominal fat that poses greater cardiovascular and metabolic risks. The NHS recommends using both metrics together for a complete picture of your health risk.
What's the difference between waist measurement thresholds for different ethnic groups?
South Asian, Chinese, Black African, and Black Caribbean populations face higher health risks at lower waist circumferences. NHS thresholds for these groups are 90cm for men and 80cm for women (compared to 94cm and 80cm for other populations), reflecting different metabolic risk profiles across ethnic groups.
How often should I measure my waist?
Monthly measurements are reasonable for weight management monitoring. If you're following a weight loss programme or taking weight loss medication, tracking every 2–4 weeks helps you see progress alongside weight and BMI. Discuss frequency with your GP based on your individual health goals.
Can I rely on waist measurement alone for health assessment?
No — waist measurement is most useful alongside BMI, weight, and other health markers like blood pressure and blood glucose. Never self-diagnose based on waist measurement alone. Your GP can assess your complete health picture and advise whether intervention is needed.
Does waist measurement change differently than overall weight?
Yes — some people lose waist circumference faster than overall weight, especially in the early stages of weight loss or when starting weight loss medication. This is positive because reducing abdominal fat specifically reduces health risks. Track both metrics to see the full benefit of lifestyle or medication changes.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.