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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MUST Score Calculator — Assess Nutritional Risk
The MUST (Malnutrition Universal Screening Tool) score is a simple, evidence-based assessment used across the UK to identify adults at risk of malnutrition. It's recommended by NICE and the British Association for Parenteral and Enteral Nutrition (BAPEN) and is widely used in GP surgeries, hospitals, care homes, and community settings. Understanding your MUST score helps you and your healthcare team identify whether nutritional support or dietary intervention may be needed to protect your health.
10,000+ calculations today · NHS-aligned thresholds · 100% free
Calculate Your BMI Instantly
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.
How MUST Score Works and What It Measures
The MUST score combines three key measurements to create a single risk assessment: body mass index (BMI), unintentional weight loss, and current acute illness status. Each component is scored separately, and the total determines whether someone is at low, medium, or high risk of malnutrition.
- BMI component: Calculated using your weight and height. Our free BMI calculator above can help you determine your current BMI instantly in UK measurements (kg, stone, or pounds).
- Weight loss component: Measures how much weight you've lost unintentionally in the past 3–6 months.
- Acute illness factor: Identifies whether you have a current medical condition affecting food intake or nutrient absorption.
A score of 0 indicates low risk, 1 indicates medium risk, and 2 or above indicates high risk. The higher your score, the more important it is to seek GP advice and dietary support.
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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.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
When You Should Use MUST Score and Next Steps
MUST screening is particularly important if you're experiencing unintentional weight loss, have a low BMI (under 18.5), are over 75 years old, have a long-term medical condition, or live in a care home. If you're concerned about weight loss or your nutritional status, speak to your GP who can perform a formal MUST assessment and refer you to a registered dietitian if needed. Your GP can also check for underlying health conditions affecting your nutrition and arrange appropriate dietary support or supplementation.
Maintaining good nutrition is essential for immunity, recovery from illness, and overall health. If you're struggling with your weight or diet, the NHS Weight Loss Plan and other community resources are available to support you.
- 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.
What's the difference between MUST score and BMI?
BMI is just one component of the MUST score. While BMI measures weight relative to height, MUST is a fuller assessment that also includes recent weight loss and acute illness status. BMI alone doesn't capture malnutrition risk — MUST does. Use our free BMI calculator to check your BMI as part of understanding your overall nutritional health.
Can I calculate my MUST score at home?
You can gather the measurements needed (height, weight, recent weight loss), but a formal MUST assessment should be done by a healthcare professional like your GP or a dietitian. They can accurately assess your acute illness status and provide clinical interpretation of your score and recommended next steps.
What counts as unintentional weight loss for MUST scoring?
Unintentional weight loss is loss that happens without deliberately trying to lose weight — often a sign of underlying illness, poor nutrition, or malabsorption. MUST considers weight loss over 3–6 months. If you've lost weight unintentionally, tell your GP, as it may indicate a health issue needing investigation.
Is MUST score only for older people?
No. While MUST is commonly used to screen older people and those in hospitals or care homes, it can be applied to any adult to identify malnutrition risk. Anyone experiencing unintentional weight loss, low BMI, or acute illness may benefit from MUST screening regardless of age.
What should I do if my MUST score is high?
If your MUST score is high, speak to your GP promptly. They may refer you to a registered dietitian, arrange blood tests to check nutrient levels, investigate the cause of weight loss, or recommend nutritional supplements or dietary changes to support your health.
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.