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
Protein Calculator For Weight Loss
Protein plays a crucial role in sustainable weight loss, helping preserve muscle, increase satiety, and support metabolic health. While there's no one-size-fits-all protein calculator, understanding your individual protein needs is essential for effective weight management. This guide explains how to calculate your protein targets, why protein matters during weight loss, and how it fits into a broader weight loss strategy alongside diet, exercise, and where relevant, prescription weight loss medication.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
How Much Protein Do You Need For Weight Loss?
Protein requirements during weight loss depend on your body weight, activity level, and weight loss method. The NHS recommends 0.8g of protein per kilogram of body weight daily as a baseline for sedentary adults, but weight loss requires more.
For effective weight loss and muscle preservation, aim for 1.2 to 2.2g of protein per kg of body weight daily. For example, an 80kg adult should target 96–176g of protein daily. Higher protein intake (toward the upper range) is particularly important if you're exercising regularly or following a low-calorie diet.
- Sedentary weight loss: 1.2–1.6g per kg
- Regular exercise: 1.6–2.0g per kg
- Intensive strength training: 2.0–2.2g per kg
Use our free BMI calculator above to determine your current weight and health context, then apply these ratios to personalise your protein target. Individual needs vary based on age, metabolism, and health conditions—your GP can provide personalised guidance.
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.
Why Protein Matters During Weight Loss
Protein is essential during weight loss because it preserves lean muscle mass, supports recovery from exercise, and increases satiety—helping you feel fuller longer. This is especially important during weight management in the UK, where sustainable approaches are prioritised over rapid loss.
When you lose weight in a calorie deficit, your body breaks down both fat and muscle. Adequate protein helps minimise muscle loss, which is crucial because muscle tissue burns more calories at rest than fat tissue. Higher protein intake also has a thermic effect—your body uses more energy to digest protein than carbohydrates or fat, supporting your overall energy expenditure.
For those using weight management injections like Mounjaro or Wegovy, maintaining adequate protein becomes even more important, as these medications reduce appetite and may lower overall calorie intake. Our GLP-1 weight loss calculator can help estimate potential weight loss outcomes when combined with proper nutrition planning.
Protein timing and distribution also matters. Rather than consuming all protein in one meal, spread it across 3–4 meals daily—this supports muscle protein synthesis throughout the day and helps maintain stable energy levels. Aim for 25–40g of protein per main meal and 10–20g per snack.
Track your progress with our free progress tracker, which helps you monitor weight loss and adjust dietary strategies over time. Remember that weight management in the UK emphasises sustainable change: combining adequate protein intake with a modest calorie deficit, regular physical activity, and behavioural support delivers the best long-term results.
- 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.
How do I calculate my daily protein needs for weight loss?
Multiply your body weight in kg by 1.2–2.2g, depending on activity level. For example, an 80kg person should aim for 96–176g daily. Use the lower end (1.2–1.6g/kg) if sedentary, higher end (1.6–2.2g/kg) if exercising regularly. Your GP can provide personalised recommendations.
Is high protein intake safe for weight loss?
Yes, protein intake up to 2.2g per kg of body weight is safe for most healthy adults. However, those with kidney disease or certain medical conditions should consult their GP first. Adequate hydration is also important when consuming higher protein amounts.
What are the best protein sources for weight loss in the UK?
Lean meats (chicken, turkey, beef), fish, eggs, Greek yoghurt, cottage cheese, lentils, beans, and tofu are excellent UK-accessible options. Plant-based sources like pulses offer added fibre, which aids satiety. Combine variety to ensure you're getting all amino acids.
Should I use a protein supplement for weight loss?
Whole food sources are ideal, but protein powders (whey, plant-based) can be convenient and cost-effective additions. They're not essential—focus first on meeting protein targets through food, then consider supplements if needed for convenience.
Does protein intake affect weight loss medication like Mounjaro or Wegovy?
No—adequate protein is actually beneficial alongside prescription weight loss injections. These medications reduce appetite, so prioritising protein helps preserve muscle mass. Our GLP-1 weight loss calculator can help project results when protein intake is optimised alongside medication use.
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.