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
Weight Loss, Back Pain and Cancer Risk — What the Evidence Shows
Excess weight can significantly increase back pain and raise the risk of certain cancers, but losing weight may help improve both conditions. The NHS recognises that sustainable weight loss through lifestyle changes — and sometimes prescription weight loss medication — can reduce these health risks. This guide explains the connections between weight, back pain, and cancer, and explores evidence-based approaches to weight management in the UK.
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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.
How Weight Affects Back Pain and Cancer Risk
Carrying excess weight places additional strain on the spine, particularly the lower back, which can trigger or worsen back pain. Extra weight also increases inflammatory markers in the body, contributing to joint pain and reducing mobility. Cancer risk is linked to excess weight through multiple mechanisms: adipose (fat) tissue produces hormones and inflammatory substances that can promote cell growth, and obesity is associated with increased risk of at least 13 types of cancer, including breast, bowel, and endometrial cancer.
The NHS emphasises that even modest weight loss — as little as 5% of body weight — can improve back pain symptoms and reduce cancer risk factors. Losing 0.5 to 1 kg per week through reduced-calorie intake and increased physical activity is the recommended sustainable approach. Use our free BMI calculator above to check your current weight category and understand your personal health profile.
Clinically BackedWeight Loss
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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.
Weight Loss Approaches: Lifestyle and Medical Options
Lifestyle changes remain the foundation of effective weight management: balanced nutrition (Mediterranean diet shows strong evidence), regular physical activity, and sustainable calorie reduction. For those struggling with self-directed weight loss, prescription weight loss medication may support additional results. GLP-1 weight loss injections like Wegovy and Mounjaro are available through NHS specialist weight management services or private prescription in the UK, and clinical trials show these may help with weight loss alongside lifestyle changes.
Whatever approach you choose, track your progress with our free progress tracker. Always consult your GP before starting new weight loss medication or significantly changing your diet or exercise routine.
Your GP can assess whether prescription weight loss medication is suitable for you based on your BMI, health conditions, and medical history. Weight management services in the UK operate through a four-tier system: tier 1 includes self-help and community programmes, tier 2 involves primary care support, tier 3 offers specialist multidisciplinary services (where prescription medications are typically managed), and tier 4 covers bariatric surgery for severe obesity. Access varies by region and waiting times can be significant, but private options are also available.
- 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.
Can weight loss really help reduce back pain?
Yes. Excess weight increases strain on the spine and inflammatory markers. Research shows that losing 5–10% of body weight can significantly reduce back pain symptoms and improve mobility. This is particularly noticeable in lower back pain, which affects many overweight individuals in the UK.
Is obesity really linked to cancer risk?
Yes, the NHS confirms that excess weight is associated with increased risk of at least 13 cancer types, including breast, bowel, endometrial, and pancreatic cancers. Mechanisms include hormonal changes, chronic inflammation, and insulin resistance. Weight loss reduces these risk factors.
What's the safest rate of weight loss recommended by the NHS?
The NHS recommends losing 0.5 to 1 kg (1–2 lbs) per week as a sustainable, safe rate. This typically requires a calorie deficit of approximately 500 kcal per day through diet and exercise combined.
Can prescription weight loss injections help with back pain?
While GLP-1 medications like Wegovy and Mounjaro are licensed for weight management, they are not specifically approved to treat back pain. However, by supporting weight loss alongside lifestyle changes, they may indirectly reduce back strain and pain. Always discuss with your GP.
How do I access NHS weight loss support?
Start by speaking to your GP, who can assess your weight and health and refer you to tier 2 or tier 3 weight management services if appropriate. Services are free but availability and waiting times vary significantly by region. Private weight loss support is also available.
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.