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 Meal Prep in the UK: Planning, Nutrition & Medication Support
Meal prep is a practical strategy for weight management in the UK. Planning and preparing meals in advance helps you stick to a reduced-calorie diet, control portions, and avoid high-calorie convenience foods. Combined with lifestyle changes, prescription weight loss medication may also help eligible adults. This guide covers practical meal prep approaches alongside information about UK-licensed weight management options available through the NHS and private prescribing.
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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-Licensed Weight Loss Medication Options
For adults with a BMI of 30 or above (or 27 or above with weight-related health conditions), prescription weight loss medications are available in the UK. These work alongside, not instead of, dietary changes and meal prep.
Three main options:
- Mounjaro (tirzepatide) — a once-weekly GIP/GLP-1 injection. Clinical trials showed average weight loss of approximately 15–21% of body weight at the highest dose alongside a reduced-calorie diet.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. Research demonstrated average weight loss of around 14.9% of body weight over 68 weeks.
- Saxenda (liraglutide) — a once-daily GLP-1 injection offering similar outcomes to Wegovy.
All are prescription-only medicines requiring clinical assessment. Individual results vary significantly. Calculate your personal BMI using our free BMI calculator to check if you might be eligible for assessment.
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 vs Private Access & Getting Started
NHS route: Referral from your GP to a tier 3 specialist weight management service. Availability varies significantly by region — waiting times can be lengthy in many areas. Your GP can advise on local services.
Private route: Online consultation with a UK-licensed prescriber followed by prescription from a GPhC-registered pharmacy. No NHS referral needed, though assessments still determine eligibility based on health criteria.
Meal prep combined with professional support works best. Use our free GLP-1 weight loss calculator to explore potential outcomes at different medication doses, and our progress tracker to log your journey alongside meal prep efforts.
- 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 meal prep alone achieve sustainable weight loss without medication?
Yes, meal prep combined with a reduced-calorie diet and physical activity can support weight loss for many people. The NHS recommends aiming for 0.5–1 kg per week. However, if you have tried lifestyle changes without sufficient results and meet eligibility criteria, prescription weight management may help. Your GP can advise on the best approach for your situation.
How does prescription weight loss medication fit with meal prep?
Medications like Mounjaro and Wegovy work alongside lifestyle changes, not instead of them. They may help reduce appetite and food cravings, making it easier to stick to your meal prep plan and maintain a calorie deficit. Clinical evidence suggests best results come from combining medication with dietary changes and increased physical activity.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are once-weekly injections licensed in the UK for weight management. Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist, whilst Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials show similar average weight loss outcomes, though individual results vary. Your prescriber will assess which is most suitable for you.
How do I find out if I'm eligible for prescription weight loss medication in the UK?
Eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions like type 2 diabetes or high blood pressure. Start by speaking with your GP, who can assess your health and refer you to specialist services if appropriate. You can also use our free BMI calculator to check your current BMI range.
What's the realistic weight loss with medication alongside meal prep?
Clinical trials show average weight loss of 14–21% of body weight over several months, though individual results vary significantly. Some people lose more, some less. Outcomes depend on the specific medication, dose reached, how consistently you use it, and your adherence to meal prep and lifestyle changes. Expect gradual, sustainable loss rather than rapid results.
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.