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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Easy Weight Loss Meal Plans in the UK
A sustainable weight loss meal plan doesn't have to be complicated. For many UK adults, combining simple dietary changes with prescription weight management medication can provide real, lasting results. Whether you're exploring meal planning alone or considering prescription options like Mounjaro or Wegovy, understanding what's available through the NHS and private prescribing can help you make informed decisions. This guide covers practical nutrition strategies and how prescription weight loss medication works alongside healthy eating.
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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
For UK adults who qualify, prescription weight loss medications can complement a structured meal plan and support sustainable weight management. Three main options are currently licensed in the UK:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist injected once weekly. Clinical trials showed participants lost an average of 15–21% of their body weight over 72 weeks, though individual results vary significantly.
- Wegovy (semaglutide) — a GLP-1 receptor agonist, also injected once weekly. STEP trial data showed average weight loss of around 15% body weight at maximum dose.
- Saxenda (liraglutide) — a GLP-1 receptor agonist given as a daily injection, suitable for adults who prefer daily dosing.
All three work by helping regulate appetite and support feeling fuller after smaller meals. Eligibility typically requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes, high blood pressure, or sleep apnoea. These are prescription-only medicines requiring clinical assessment before being prescribed.
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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.
NHS vs Private Prescribing in the UK
In the UK, prescription weight loss medication is available through two routes. NHS access is through tier 3 specialist weight management services — typically requiring a referral from your GP. Availability varies significantly by region, and waiting lists can be several months or longer in many areas. Private prescribing is available through GPhC-registered online prescribers following a clinical assessment, without needing an NHS referral.
Whichever route you explore, medication works best alongside a reduced-calorie diet and increased physical activity. Use our free BMI calculator to check your starting point, and try our GLP-1 weight loss calculator to understand potential outcomes at different doses. Your GP can assess your individual eligibility and discuss which option suits your circumstances.
- 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 lose weight with just a meal plan, without medication?
Yes. A structured meal plan with a calorie deficit of around 500 kcal per day can result in sustainable weight loss of approximately 0.5 kg per week. The NHS recommends this approach as a first step. However, if you've tried dietary changes without sufficient results, prescription medication may be an option to discuss with your GP.
What makes an easy weight loss meal plan actually work?
Simplicity and sustainability matter most. Focus on whole foods, adequate protein, plenty of vegetables, and consistent portion control. Avoid very restrictive diets — they're harder to stick to long-term. Pairing a realistic meal plan with increased physical activity and, if eligible, prescription support, typically gives the best results.
How much weight can I expect to lose with Mounjaro or Wegovy?
Clinical trials showed average weight loss of 15–21% body weight with Mounjaro and around 15% with Wegovy, but individual results vary significantly. Weight loss depends on your starting weight, adherence to a reduced-calorie diet, physical activity, and individual metabolism. Your GP or prescriber can give you a more personalised estimate.
How do I know if I'm eligible for prescription weight loss medication in the UK?
UK eligibility generally requires a BMI of 30 or above, or 27–29.9 with a weight-related health condition. South Asian, Chinese, Black African, and Black Caribbean adults may have lower thresholds due to higher health risks. Contact your GP for an assessment, or use our free BMI calculator to check your current category.
Should I use a meal plan or medication first?
Most UK healthcare providers recommend starting with structured meal planning and lifestyle changes. If this doesn't produce sufficient results after several months, or if you have significant obesity-related health conditions, prescription medication may be considered alongside continued dietary changes. Your GP can advise the best approach for your situation.
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.