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
Free tracker included with every download this week
Fat Reduction: A UK Health Guide to Safe and Sustainable Weight Management
Fat reduction is a key component of healthy weight management in the UK, supported by NHS guidance and evidence-based health advice. Whether through lifestyle changes, dietary adjustments, or medical support, reducing excess body fat can significantly improve your health outcomes. This guide covers NHS recommendations, how to approach fat reduction safely, and the UK resources available to support your journey toward a healthier weight.
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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.
NHS Guidance on Fat Reduction and Healthy Weight Management
The NHS recommends a gradual, sustainable approach to reducing body fat — typically losing 0.5 to 1 kg per week for long-term success. This rate of loss helps preserve muscle mass and makes dietary changes easier to maintain. According to NHS guidance, a calorie deficit of around 500 kcal per day generally results in approximately 0.5 kg weight loss per week.
- Combine dietary changes with regular physical activity — both are essential for sustainable fat reduction
- Focus on whole foods, lean proteins, vegetables, and fibre-rich carbohydrates
- Stay hydrated and prioritise adequate sleep, which supports metabolism and reduces cravings
- For adults with a BMI of 30 or above, or 27 or above with weight-related health conditions, NHS specialist services may offer prescription weight management support alongside lifestyle changes
The NHS emphasises that fat reduction is not just about appearance — losing even 5–10% of your body weight can meaningfully reduce your risk of type 2 diabetes, cardiovascular disease, and other weight-related health conditions. Your GP can provide personalised guidance based on your individual health profile and help you access appropriate support services.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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.
UK Tools and Resources to Support Your Fat Reduction Journey
Understanding your starting point is essential. Use our free BMI calculator to assess your current healthy weight range according to NHS standards — this helps you set realistic fat reduction targets. Our weight converter makes it easy to track progress across kg, stone, and pounds, which is especially useful since UK adults typically measure weight in stone.
If you're considering medical support, our GLP-1 weight loss calculator can help you understand how prescription weight management medications might fit alongside lifestyle changes. For ongoing support, track your progress with our free progress tracker and always consult your GP before starting any new diet, exercise programme, or considering prescription medication for weight management.
- 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 is the safest rate of fat reduction?
The NHS recommends losing 0.5 to 1 kg per week for sustainable, safe fat reduction. This rate helps preserve muscle mass and makes lifestyle changes easier to maintain long-term. Very gradual weight management should only be attempted under medical supervision.
Can I reduce fat without changing my diet?
Exercise alone is less effective than combining diet and physical activity. Fat reduction requires a calorie deficit, which is most effectively achieved through both dietary changes and regular exercise. The NHS emphasises both components.
What does NHS guidance say about fat reduction medication?
The NHS offers prescription weight management medications (such as GLP-1 injections) through specialist tier 3 and tier 4 services for eligible adults. These are used alongside reduced-calorie diets and increased physical activity, not instead of them.
How can I tell if I have excess body fat?
BMI is a useful screening tool, but it has limitations as it doesn't distinguish between muscle and fat. Your GP can assess your individual risk using BMI, waist circumference, and other health markers relevant to your specific situation.
Where can I get support for fat reduction in the UK?
Start with your GP, who can provide personalised advice and refer you to NHS weight management services if appropriate. Many NHS areas offer community programmes, and your GP can discuss prescription options if you meet eligibility criteria.
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.