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
Is Protein Diet Good For Weight Loss?
Yes, protein can support weight loss when combined with a reduced-calorie diet. Higher protein intake helps preserve muscle during weight loss, increases feelings of fullness, and slightly boosts calorie burn. However, diet alone is not always enough—many UK adults struggling with weight management also benefit from prescription weight loss medication alongside lifestyle changes. Our free BMI calculator can help you determine your current health status, and if you're eligible, prescription options like Mounjaro or Wegovy may be recommended through NHS or private pathways.
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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.
Protein Diet and Weight Loss: The Evidence
How protein supports weight loss: Protein increases satiety—you feel fuller for longer after eating—which naturally reduces calorie intake. Protein also has a higher thermic effect than carbohydrates or fats, meaning your body burns slightly more calories digesting it. Clinical evidence supports this: research shows high-protein diets (typically 1.2–2.2g per kg of body weight daily) result in modestly better weight loss outcomes than standard diets, particularly when combined with resistance exercise to preserve muscle mass.
For nhs weight loss guidance, the NHS emphasizes that sustainable weight management uk involves both dietary changes and increased physical activity. Protein-rich foods like chicken, fish, eggs, beans, and Greek yoghurt are recommended as part of a balanced, reduced-calorie eating plan. However, if you've tried diet and exercise without sufficient results, prescription weight loss medication nhs services may be available to you through your GP or specialist weight management services, depending on your BMI and health circumstances.
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.
UK Prescription Weight Loss Options for Eligible Adults
If you have a BMI weight loss concern and meet eligibility criteria, three prescription-only medications are licensed for weight loss uk management: Mounjaro (tirzepatide), a dual GIP/GLP-1 injection; Wegovy (semaglutide), a GLP-1 injection; and Saxenda (liraglutide), a daily injection. Eligibility typically requires a BMI of 30 or above, or 27–29.9 with a weight-related health condition such as type 2 diabetes or high blood pressure.
Access is available through NHS weight loss injections uk specialist services (tier 3 weight management) or private prescribing following online clinical assessment. These are designed to work alongside diet and exercise—not replace them. Our glp-1 weight loss calculator can help you estimate potential outcomes at different doses if you're considering medication-supported weight loss.
- 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.
Does eating more protein clinically studied weight loss?
No. Weight loss requires a calorie deficit—protein alone won't cause weight loss without reducing overall calories. However, protein helps you feel fuller on fewer calories, making a deficit easier to maintain. Combined with exercise and lifestyle changes, higher protein intake supports better outcomes than low-protein diets at the same calorie level.
What's the best source of protein for weight loss?
Lean sources are ideal: chicken breast, fish, eggs, low-fat Greek yoghurt, cottage cheese, and plant-based options like lentils and tofu. These are nutrient-dense and low in calories. Processed high-protein foods (bars, shakes) can be convenient but often contain added sugars—read labels carefully.
How much protein should I eat daily for weight loss?
The NHS and most evidence supports 1.2–1.6g of protein per kg of body weight daily during weight loss. For a 70kg person, this is roughly 84–112g daily. This preserves muscle mass, maintains strength, and supports satiety. Your GP or a registered dietitian can personalise this recommendation based on your activity level and health.
Can I lose weight with protein diet alone, without exercise?
Diet is more important than exercise for weight loss, but they work best together. A protein-rich, reduced-calorie diet alone will result in weight loss, but adding resistance exercise helps preserve muscle mass and bone health. If lifestyle changes aren't delivering results, talk to your GP about whether prescription weight management medication might be suitable.
How do prescription weight loss injections like Mounjaro compare to diet?
Prescription medications like Mounjaro (tirzepatide) are prescribed alongside diet and exercise, not instead of them. Clinical trials show Mounjaro helps people lose 15–21% of body weight on average—significantly more than diet alone typically achieves. Your prescriber will assess eligibility and discuss whether this option suits your circumstances.
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.