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
Building a Custom Weight Loss Program in the UK
A custom weight loss program tailored to your individual health needs offers the best chance of sustainable success. Rather than following a generic diet, the most effective approach combines your personal circumstances—including your BMI, health conditions, lifestyle, and preferences—with evidence-based strategies. In the UK, support ranges from NHS weight management services to prescription options like GLP-1 weight loss medications, all designed to work alongside dietary changes and increased physical activity. This guide explores how to create a personalised plan that actually fits your life.
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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.
What Makes a Weight Loss Program Effective?
A successful custom weight management uk approach addresses three core elements: realistic calorie deficit, behavioural change, and medical support where needed. The NHS recommends losing weight at a rate of 0.5 to 1 kg per week for sustainable results—faster loss often leads to muscle loss and weight regain.
- Calculate your personal calorie needs using your BMI and activity level
- Use our free BMI calculator above to establish your starting point and healthy weight range
- Identify trigger foods and eating patterns that work against your goals
- Build in regular physical activity—even modest increases improve outcomes significantly
- Track progress weekly using our free progress tracker to stay motivated and accountable
For those with a BMI of 30 or above, or 27 or above with weight-related health conditions, prescription weight loss medication may be available. These are used alongside, not instead of, lifestyle changes. Your GP can assess whether medication is appropriate for your individual situation.
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.
NHS and Private Support Options for Weight Loss
In the UK, nhs weight loss support is delivered through a four-tier system. Tier 1 includes self-help tools and community programmes (like the free NHS Weight Loss Plan). Tier 2 involves primary care interventions from your GP. Tier 3 offers specialist multidisciplinary weight management services—where prescription medications like GLP-1 weight loss injections may be considered. Tier 4 covers bariatric surgery for severe obesity.
Many people also access prescription weight loss uk medications through private online prescribing services, which offer faster access without NHS waiting lists. Whether you choose NHS or private support, a custom programme should include regular monitoring, dietary guidance, physical activity support, and psychological help if needed. Use our GLP-1 weight loss calculator to explore how medications like semaglutide (Wegovy) or tirzepatide (Mounjaro) might fit into your personalised plan.
- 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 a generic diet and a custom weight loss program?
A generic diet follows a one-size-fits-all approach, whereas a custom program considers your individual BMI, health conditions, food preferences, lifestyle, work schedule, and metabolism. Personalised programmes have higher long-term success rates because they're sustainable and realistic for your life, not someone else's.
Can I access prescription weight loss medication through the NHS?
Yes, if you meet eligibility criteria. You need a BMI of 30 or above, or 27 or above with weight-related conditions like type 2 diabetes or high blood pressure. Access is through specialist tier 3 weight management services via NHS referral. Availability and waiting times vary significantly by region.
How do GLP-1 medications like Wegovy fit into a custom weight loss program?
GLP-1 medications such as semaglutide (Wegovy) are prescription-only and work best alongside reduced-calorie diet and physical activity. In clinical trials, they helped participants lose an average of 15% of body weight, though individual results vary. They're used when lifestyle changes alone haven't been successful or to support ongoing weight management.
How often should I adjust my custom weight loss program?
Review your program every 4–6 weeks. If you're losing weight consistently at 0.5–1 kg per week, continue current strategies. If progress stalls, adjust calorie intake slightly or increase physical activity. Work with your GP or a dietitian for personalised adjustments rather than making major changes independently.
What role does tracking play in a successful custom program?
Regular tracking—whether weight, food intake, or activity—improves accountability and reveals patterns. Our free progress tracker helps you log weekly weight changes and spot trends over time. Tracking also helps your GP or prescriber assess whether medication adjustments or other changes are needed.
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.