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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Weight Loss Meal Planner: Medication & Nutrition in the UK
A weight loss meal planner is most effective when combined with the right support—and in the UK, that now includes prescription medication options for eligible adults. Whether you're managing weight through NHS services or private prescribing, understanding how to balance nutrition with evidence-based medication can significantly improve your results. This guide covers UK-licensed weight management options, who is eligible, and how meal planning fits into an integrated approach to sustainable weight loss.
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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.
UK Prescription Weight Loss Options: Medication-Supported Meal Planning
Three prescription medications are currently licensed in the UK for weight management, and all work best alongside structured meal planning and increased physical activity:
- Mounjaro (tirzepatide) — A dual GIP and GLP-1 receptor agonist. Clinical trials showed participants lost an average of 15–21% of body weight at the highest dose, alongside a reduced-calorie diet. Once-weekly injection.
- Wegovy (semaglutide) — A GLP-1 receptor agonist. Average weight loss in clinical trials was approximately 15% of body weight. Once-weekly injection.
- Saxenda (liraglutide) — A daily GLP-1 injection with lower average weight loss outcomes compared to Mounjaro and Wegovy, but still effective for some individuals.
All three are prescription-only and require clinical assessment. Individual results vary significantly. These medications work by reducing appetite and helping you feel fuller on smaller portions—which is why pairing them with a structured meal planner makes sense. Try our free GLP-1 weight loss calculator to estimate potential outcomes at different doses.
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 Eligibility & How to Access Weight Loss Medication
In the UK, prescription weight loss medication is available through two main routes: NHS specialist tier 3/tier 4 weight management services, or private prescribing following an online clinical assessment.
NHS route: You must have a BMI of 30 or above, or 27–29.9 with at least one weight-related health condition (such as type 2 diabetes, high blood pressure, or sleep apnoea). Referral typically comes from your GP to a specialist weight management service. Availability and waiting times vary significantly by region. For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds apply.
Private route: Available without NHS referral through licensed UK prescribers following an online consultation. Access is faster but requires private payment.
Speak to your GP about whether prescription weight loss medication is appropriate for you. Calculate your BMI using our free BMI calculator to understand where you stand against NHS thresholds.
- 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 I use a meal planner without weight loss medication?
Absolutely. Sustainable weight loss can be achieved through meal planning, calorie deficit, and increased physical activity alone. The NHS recommends losing 0.5–1 kg per week through dietary changes and exercise. Prescription medication is an option for eligible adults who would benefit from additional support, but many people successfully manage their weight through nutrition and lifestyle alone.
How does GLP-1 medication change how I should plan meals?
GLP-1 medications like Mounjaro and Wegovy help you feel fuller on smaller portions, which means your meal planner can focus on nutrient-dense, satisfying foods rather than large volumes. You may find you naturally eat less, experience fewer cravings, and have more stable energy levels. A dietitian or nutritionist familiar with GLP-1 medication can tailor a meal plan to your specific needs.
What is the difference between Mounjaro and Wegovy?
Both are once-weekly injections, but Mounjaro (tirzepatide) uses a dual GIP and GLP-1 mechanism, while Wegovy (semaglutide) targets GLP-1 alone. Clinical trial data suggests Mounjaro may produce slightly greater average weight loss, but individual results vary. Both are prescription-only and require clinical assessment. Ask your prescriber which is most suitable for you.
How long does weight loss medication take to work?
Most people begin noticing appetite changes within the first few weeks, though weight loss is usually gradual. Clinical trials measured results over 68–72 weeks. Sustainable weight loss is typically 0.5–1 kg per week. Combined with a structured meal plan, medication can support steady, lasting progress. Our progress tracker helps you monitor your results over time.
Can I get weight loss medication on the NHS?
Yes, if you meet eligibility criteria (BMI ≥30, or ≥27.5 with weight-related health conditions) and are referred to a specialist tier 3 weight management service by your GP. Availability varies by region and waiting times can be lengthy. Private prescribing is faster but involves costs. Ask your GP about NHS options in your area first.
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.