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
Which Protein Powder Is Best For Weight Loss?
Protein powder can be a useful tool for weight management in the UK, but there's no single "best" option — the right choice depends on your lifestyle, diet, and fitness goals. Protein supports weight loss by helping you feel fuller for longer, preserving muscle during a calorie deficit, and boosting metabolism slightly. When combined with a reduced-calorie diet and physical activity, quality protein intake (whether from powder or whole foods) plays an important role in sustainable weight management. This guide explains what to look for and how to choose wisely.
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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.
What Makes Protein Powder Effective For Weight Loss?
Protein powder works for weight loss through several mechanisms. Increased satiety: protein triggers fuller signals in your brain, meaning you feel satisfied on fewer calories. Muscle preservation: during a calorie deficit, adequate protein (1.2–1.6g per kg body weight daily) prevents muscle loss, which is crucial because muscle burns more calories at rest than fat. Thermic effect: digesting protein uses more energy than digesting carbohydrates or fats, increasing daily calorie expenditure by around 20–30%.
However, protein powder is a supplement, not a replacement for whole foods or lifestyle changes. The NHS emphasises that sustainable weight loss requires a calorie deficit alongside increased physical activity — no food or supplement alone creates lasting results. Protein powder is most effective when it replaces high-calorie snacks or helps you meet daily protein targets easily, not when added on top of your normal diet.
- Best used alongside reduced-calorie diet and exercise
- Helps preserve muscle during weight loss
- Supports feeling fuller for longer
- Most effective for active individuals who exercise regularly
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.
Comparing Protein Powder Types For Weight Loss
Whey protein: fastest-absorbing, highest in leucine (an amino acid that triggers muscle protein synthesis), most researched for weight loss. Best post-workout. Casein protein: slower-digesting, provides sustained release of amino acids, excellent for between meals or before bed. Plant-based (pea, hemp, rice, soy): suitable for vegans and those with dairy intolerance, though often lower in leucine unless blended. Soy is a complete protein with all nine amino acids.
When choosing, prioritise: low added sugar (under 5g per serving), minimal artificial ingredients, at least 20g protein per serving, and reputable third-party testing for quality. Price varies widely — expensive doesn't always mean better. Our free BMI calculator and GLP-1 weight loss calculator can help you establish your current baseline and projected outcomes with different approaches to weight management, including the role of protein in your overall strategy.
- 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.
Is protein powder better than whole food protein for weight loss?
No. Whole foods like chicken, fish, eggs, Greek yoghurt, and beans provide additional nutrients and fibre that powder lacks. Use powder for convenience — to meet targets when whole food isn't practical — not as a complete replacement. Both work well in combination.
How much protein powder should I take daily for weight loss?
Aim for 1.2–1.6g of total protein per kg of body weight daily (from all sources). If you weigh 70kg, that's 84–112g daily. Use our free weight converter and BMI calculator to establish your baseline, then calculate your protein needs with your GP or a dietitian for personalised guidance.
Can protein powder alone help me lose weight?
No. Protein powder supports weight loss only within a calorie deficit. You still need to consume fewer calories than you burn, combined with regular physical activity. The NHS recommends 0.5–1kg weight loss per week for sustainable results — diet and exercise drive this, not supplements alone.
Is whey or plant-based protein better for weight loss?
Both work if they fit your dietary needs. Whey absorbs faster and has higher leucine, beneficial post-exercise. Plant-based works equally well if you meet daily protein targets. Choose based on allergies, ethics, and personal preference — consistency matters more than the type.
Should I use protein powder if I'm taking prescription weight loss medication?
Yes, protein powder can complement prescription weight management medications like GLP-1 injections by helping preserve muscle during weight loss. Discuss your overall nutrition plan with your GP or prescriber to ensure protein intake aligns with your specific health needs.
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.