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
Exercise and Weight Loss — How Activity Supports Weight Management
Exercise is one of the most effective tools for sustainable weight loss, but it works best alongside dietary changes. While physical activity burns calories and builds muscle, evidence shows that weight management in the UK requires a combination of reduced calorie intake, regular movement, and sometimes prescription medication. Understanding how exercise contributes to weight loss — and its limitations — helps you create a realistic, long-term approach to reaching a healthier weight.
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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.
How Exercise Supports Weight Loss
Exercise burns calories during activity and increases your metabolic rate, meaning you burn more energy even at rest as you build muscle. The NHS recommends at least 150 minutes of moderate-intensity activity per week for adults, which can support gradual weight loss. Moderate intensity means activities like brisk walking, cycling, or swimming where you can talk but not sing.
- Cardiovascular exercise (running, cycling, swimming) burns significant calories during the activity itself
- Strength training builds muscle mass, which increases resting metabolic rate
- Regular activity improves blood sugar control and insulin sensitivity
- Exercise reduces appetite hormones and supports better food choices
- Physical activity strengthens bones, joints, and cardiovascular health regardless of weight loss outcome
However, exercise alone rarely produces the weight loss needed to meet NHS health targets. The NHS recognises that for many people, combining lifestyle changes with prescription weight loss medication produces better results than exercise and diet alone.
Clinically BackedWeight Loss
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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.
Combining Exercise With Weight Loss Medication
Prescription weight loss medications like GLP-1 injections work best alongside regular activity and reduced calorie intake. In clinical trials, participants who combined medication with exercise and dietary changes lost significantly more weight than those relying on exercise alone. If you're eligible for weight loss medication in the UK — based on BMI and health factors — your GP or prescriber can assess whether this approach suits you.
Calculate your personal BMI using our free BMI calculator to understand where you fall on the NHS weight categories, then discuss your options with your healthcare provider. Remember: sustainable weight management combines physical activity, nutrition, and sometimes medical support tailored to your individual needs.
- 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 many calories does exercise burn?
Calorie burn varies widely by activity type, intensity, and body composition. A 70kg person cycling for 30 minutes burns approximately 200–300 calories; running burns 250–400 calories. High-intensity activity burns more per minute but is harder to sustain. Focus on consistency rather than individual session calories.
Can I lose weight through exercise without changing diet?
Losing significant weight through exercise alone is very difficult. Weight loss requires a calorie deficit, which diet controls most effectively. Exercise supports weight loss by increasing daily calorie expenditure, but most evidence shows that combining activity with reduced-calorie eating produces the best results.
What's the best exercise for weight loss?
The best exercise is the one you'll do consistently. Combining cardiovascular activity (150+ minutes weekly per NHS guidance) with strength training produces the best outcomes. Walking, cycling, swimming, and running are all effective. Your preference and fitness level matter more than the specific activity.
Does exercise speed up weight loss on GLP-1 medication?
Clinical trials show that combining prescription weight loss medication with regular activity and dietary changes produces better results than medication alone. Exercise supports metabolic health, builds muscle, and helps maintain weight loss long-term — making it a valuable complement to prescription treatment.
How long before exercise alone leads to weight loss?
You may see improvements in fitness and energy within 2–4 weeks, but significant weight loss typically requires calorie deficit through diet. Most people combining 150 minutes weekly exercise with reduced-calorie eating lose approximately 0.5–1 kg per week — the rate the NHS recommends as sustainable.
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.