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
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Couch to 5K Weight Loss — A Practical UK Guide
The Couch to 5K (C25K) running programme is a popular 9-week plan that builds fitness gradually, starting from a sedentary lifestyle and progressing to running 5km continuously. While C25K is primarily a fitness programme rather than a weight loss plan, it can support sustainable weight management when combined with proper nutrition and calorie awareness. This guide explains how C25K works, its role in weight loss, and how to maximise results alongside NHS weight loss strategies and other approaches to weight management UK adults can use.
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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 Couch to 5K Supports Weight Loss
Couch to 5K creates a calorie deficit through regular aerobic activity, burning approximately 300–400 calories per 30-minute run depending on your current weight and fitness level. The programme is effective because it's gradual and sustainable — starting with alternating walk-run intervals and progressing over 9 weeks to continuous running. This progressive approach reduces injury risk and improves adherence compared to sudden intense exercise.
- Week 1–3: Walk-run intervals (90 seconds running, 90 seconds walking)
- Week 4–6: Longer running intervals with shorter walk breaks
- Week 7–9: Continuous 5km runs, three times weekly
Weight loss from C25K alone is typically modest — around 0.5–1kg per week if combined with a balanced diet. The NHS recommends losing no more than 0.5–1kg weekly for sustainable results. Running also improves cardiovascular health, strengthens bones, and boosts mood — benefits that extend beyond the number on the scales.
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.
Maximising Weight Loss Results with C25K
C25K works best when paired with calorie awareness and nutrition changes. A typical 500 calorie daily deficit (achieved through diet and exercise combined) supports steady weight loss. Use our free BMI calculator to establish your starting point and healthy weight range, then track your progress as you combine running with modest dietary adjustments.
For adults struggling with motivation or needing additional support, prescription weight loss medication available through NHS weight loss services or private assessment may complement exercise programmes. Weight management UK approaches combine multiple strategies: regular physical activity, nutritional changes, behavioural support, and sometimes medication. Consider consulting your GP if you've tried diet and exercise alone without results — they can discuss bespoke options including tier 3 weight management services.
- 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 much weight can I lose doing Couch to 5K?
Weight loss depends primarily on diet rather than exercise alone. Couch to 5K typically burns 300–400 calories per session. Combined with a balanced diet and 500 calorie daily deficit, you might lose 0.5–1kg weekly. Results vary significantly based on starting weight, age, metabolism, and dietary changes. Track your progress consistently using our free progress tracker to monitor results.
Can I do Couch to 5K if I'm overweight?
Yes, Couch to 5K is specifically designed for sedentary people regardless of weight. The walk-run intervals reduce joint stress compared to continuous running. However, if you have a BMI over 40 or existing joint pain, consult your GP first. They may recommend starting with lower-impact activity like walking or cycling, or referring you to NHS weight loss services for structured support.
Do I need to diet while doing Couch to 5K?
Exercise alone rarely produces significant weight loss — diet is crucial. Aim for a modest calorie deficit (around 500 calories daily) through balanced meals, not extreme restriction. The NHS recommends steady weight loss of 0.5–1kg per week. Combine C25K with consistent healthy eating for sustainable results rather than relying on exercise to compensate for excess calories.
How long does it take to see weight loss results from C25K?
Most people notice changes after 4–6 weeks of consistent running combined with dietary changes. Initial weight loss may include water weight. Visible body composition changes typically take 8–12 weeks. Stick with the full 9-week programme and maintain consistent nutrition habits — results accumulate gradually but steadily.
Should I consider weight loss injections alongside Couch to 5K?
Prescription weight loss medications like GLP-1 injections may be appropriate if you've tried sustained diet and exercise without adequate results. These require clinical assessment and are typically prescribed through NHS specialist services or private prescribing. Our GLP-1 weight loss calculator can help estimate potential results if prescribed. Always discuss options with your GP before starting any medication.
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.