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's the Best Macro Ratio for Weight Loss?
There's no single "perfect" macro ratio for weight loss—what matters most is finding a calorie deficit that you can sustain. The macronutrient balance (protein, carbohydrates, and fats) plays a supporting role in your weight management UK approach, but individual needs vary based on your lifestyle, health conditions, and preferences. This guide explains how to think about macros within a broader weight loss strategy, whether you're managing weight through diet alone or alongside 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.
Common Macro Ratios and How They Work
Several macro ratios have research support for weight loss, though none is universally "best":
- Balanced approach (40% carbs, 30% protein, 30% fat): Suits most people and aligns with NHS guidelines. Sustainable long-term.
- Higher protein (35% protein, 35% carbs, 30% fat): Supports muscle retention, increases satiety, and may boost metabolism slightly. Helpful during calorie deficit.
- Lower carb (25% carbs, 35% protein, 40% fat): Can reduce appetite for some people, though individual response varies. Requires careful micronutrient planning.
- Mediterranean-style (45% carbs, 25% protein, 30% fat): Strong evidence for cardiovascular health and sustainable weight loss outcomes.
The key principle: calories still determine weight loss. A calorie deficit of around 500 kcal per day typically results in losing approximately 0.5 kg per week. Macro ratio influences how you *feel* during that deficit—satiety, energy levels, muscle preservation—but not the fundamental weight loss equation.
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.
Macros and Prescription Weight Loss Medication
If you're using prescription weight loss medication like GLP-1 injections (such as Wegovy or Mounjaro), macro balance becomes easier to manage. These medications reduce appetite and help you feel fuller on smaller portions, which naturally reduces overall calorie intake. However, adequate protein intake remains important to preserve muscle mass during weight loss. Aim for at least 1.2–1.6g protein per kg of body weight if you're on weight loss medication, alongside a calorie deficit and increased physical activity. Our GLP-1 weight loss calculator can help you estimate potential weight loss projections, while tracking your macros and progress with consistent logging supports your best 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.
What's the ideal macro ratio recommended by the NHS for weight loss?
The NHS doesn't prescribe a single macro ratio but supports a balanced, calorie-controlled approach. A reasonable starting point is 40% carbohydrates, 30% protein, and 30% fat, adjusted based on your preferences and how you feel. Work with your GP if you have specific health conditions affecting macro needs.
Is higher protein better for weight loss?
Higher protein (around 35% of calories) can support weight loss by increasing satiety, preserving muscle during a calorie deficit, and slightly boosting metabolism. However, the calorie deficit remains the primary driver of weight loss—macro ratio is secondary.
Does macro ratio matter more than total calories?
No. Total calories determine weight loss; macro ratio influences how you feel during that deficit. You could lose weight on almost any macro split if calories are controlled, but the right macro ratio for *you* helps you stick to your calorie target long-term.
Should I track macros when using Wegovy or Mounjaro?
You don't need precise macro tracking on GLP-1 medication, but maintaining adequate protein intake is important to preserve muscle mass. Most people find their appetite naturally reduces, making calorie control easier without strict macro counting.
What's the best macro ratio if I have type 2 diabetes?
Discuss this with your GP or a registered dietitian. Some people with type 2 diabetes benefit from slightly lower carbohydrate ratios to improve blood sugar control, while others thrive on balanced macros. Your individual medical context guides the best 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.