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
What Makes a Good Meal Replacement for Weight Loss?
A good meal replacement for weight loss should provide balanced nutrition while creating a calorie deficit, support sustained energy levels, and fit into your lifestyle long-term. In the UK, meal replacements range from high-protein shakes to portion-controlled ready meals, each with different benefits depending on your needs. The key is choosing options that are nutritionally complete, help you feel satisfied between meals, and work alongside other weight management strategies like increased physical activity. Whether you're exploring dietary approaches to weight management uk or considering prescription options, understanding meal replacements is essential for effective, sustainable weight loss.
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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.
Essential Features of Effective Meal Replacements
A quality meal replacement should contain adequate protein (at least 15–20g per serving) to help maintain muscle mass during weight loss and keep you feeling fuller for longer. Look for options with balanced carbohydrates and healthy fats rather than high sugar content, as this supports stable energy and reduces cravings.
- Protein content: 15–25g per serving helps preserve muscle and increases satiety
- Fibre: 3–5g supports digestive health and sustained fullness
- Calorie range: 150–300 calories per serving for a typical meal replacement
- Micronutrients: Should contain vitamins and minerals to cover daily needs
- Sugar content: Ideally under 5g added sugar per serving
Popular UK meal replacement options include high-protein shakes, soup-based replacements, and portion-controlled ready meals. The best choice depends on your preferences, schedule, and whether you're using meal replacements alongside nhs weight loss support or as part of a broader dietary strategy. Many people find that combining meal replacements with regular meals creates a sustainable approach to lose weight uk effectively.
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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.
Meal Replacements and Weight Loss Medication
If you're considering weight loss injections uk like Wegovy or Mounjaro, meal replacements work well alongside these prescription options. Both medications help reduce appetite and food cravings, making it easier to stick to smaller portions or use meal replacements without feeling deprived.
Clinical evidence shows that prescription weight loss medication combined with dietary changes—including meal replacements—produces better results than either approach alone. Our free GLP-1 weight loss calculator can help you estimate potential outcomes when combining meal replacements with medication. Always consult your GP before starting any weight loss medication, as eligibility depends on your individual health profile and BMI.
- 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.
Are meal replacements suitable for long-term weight loss?
Meal replacements can be part of a long-term strategy, but shouldn't replace all meals indefinitely. They work best when used for 1–3 months alongside lifestyle changes, then gradually reintroduced to regular balanced eating. This prevents nutrient deficiencies and helps develop sustainable eating habits. Use our free progress tracker to monitor your results over time.
What's the difference between meal replacements and slimming injections?
Meal replacements are low-calorie foods or drinks you eat; slimming injections (like Wegovy or Mounjaro) are prescription medications that reduce appetite. Both can support weight loss, but injections require clinical assessment and a prescription. Many people use both together—meal replacements as their dietary choice, with medication supporting appetite control.
How much weight can you lose using meal replacements?
Weight loss from meal replacements depends on your calorie deficit, starting weight, and activity level. A typical calorie reduction of 500 kcal daily (often achieved using one meal replacement) supports loss of around 0.5kg per week. Results vary significantly between individuals. Check your BMI and healthy weight range using our free BMI calculator.
Are UK high-street meal replacements NHS-approved?
The NHS doesn't "approve" specific brands, but recognises meal replacement approaches in weight management guidance. Popular UK options like Slim-Fast, Huel, and ready-meal programmes are nutritionally adequate. Your GP can advise whether meal replacements suit your health profile and weight loss goals.
Can you use meal replacements with weight loss medication?
Yes, meal replacements complement weight loss medication well. GLP-1 medications like Wegovy reduce appetite, making meal replacements easier to stick to. However, always inform your prescriber about your dietary approach. They'll ensure your overall nutrition remains balanced and monitor your progress with our weight management uk approach. ```
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.