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
Clean Eating and Weight Loss — Evidence-Based Guidance
Clean eating—focusing on whole, unprocessed foods—can be an effective approach to weight management when combined with a calorie deficit. Unlike fad diets, clean eating emphasises sustainable lifestyle changes aligned with NHS weight loss guidance. This approach prioritises nutritious, minimally processed foods whilst maintaining the calorie reduction needed for gradual, healthy weight loss. Understanding how clean eating fits into your overall weight management strategy can help you lose weight at the recommended rate of 0.5 to 1 kg per week.
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 Clean Eating Supports Weight Loss
Clean eating promotes weight loss through several evidence-based mechanisms. Whole foods like vegetables, lean proteins, legumes, and wholegrain cereals are naturally more satiating than processed alternatives—meaning you feel fuller for longer on fewer calories. This supports the fundamental principle of weight loss: a calorie deficit of around 500 kcal per day typically results in losing approximately 0.5 kg per week.
Clean eating also improves metabolic health. Foods rich in fibre slow digestion and stabilise blood sugar, reducing energy crashes and cravings that often derail weight loss efforts. Replacing sugary drinks, ultra-processed snacks, and foods high in saturated fat with nutritious alternatives reduces overall calorie intake without requiring extreme restriction.
The NHS recommends combining dietary changes with increased physical activity for sustainable results. Use our free BMI calculator above to establish your current weight category, then track your progress as you implement dietary changes and build activity into your routine.
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.
Clean Eating vs. Weight Loss Medications
For many people, clean eating alone achieves sustainable weight loss—particularly for those with BMI 25–30 who don't have weight-related health conditions. However, weight loss medication may be recommended alongside dietary changes for those with a BMI of 30 or above, or 27 or above with conditions like type 2 diabetes or high blood pressure.
Prescription weight loss medications such as GLP-1 injections work alongside clean eating, not instead of it. They help reduce appetite and food cravings—making it easier to maintain a calorie deficit—but still require dietary changes and physical activity for best results. If you're considering weight loss medication, our GLP-1 weight loss calculator can help estimate potential outcomes when combined with lifestyle changes. Always discuss options with your GP to determine the right approach for your individual circumstances.
Clean eating works best as a long-term lifestyle rather than a temporary diet. Focus on: eating vegetables and fruit at every meal; choosing unrefined wholegrain carbohydrates; selecting lean proteins like chicken, fish, and legumes; preparing meals at home where possible; and limiting added sugars, salt, and ultra-processed foods.
Track your weight loss progress using our free progress tracker to monitor results over 4–8 weeks. Sustainable weight loss takes time, and consistency matters more than perfection. If you're not seeing results after 8–12 weeks of clean eating with appropriate calorie reduction, speak with your GP—they can assess whether additional support, such as a structured NHS weight management programme, would help.
- 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.
Does clean eating clinically studied weight loss?
Clean eating supports weight loss when combined with a calorie deficit, but doesn't assures it. Portion sizes matter—even healthy foods contribute calories. The key is consuming fewer calories than you burn. Individual results vary based on metabolism, activity level, and how strictly you follow dietary changes. Our BMI calculator can help assess your starting point.
What's the difference between clean eating and calorie counting?
Clean eating focuses on food quality—whole, unprocessed, nutrient-dense options. Calorie counting tracks portion sizes and energy intake precisely. Both approaches can support weight loss; many people find clean eating easier to sustain long-term because it emphasises nutritious foods rather than restriction. Combining both—choosing clean foods within a calorie target—often works best.
Can I use clean eating with weight loss injections like Mounjaro or Wegovy?
Yes. Prescription weight loss medications are designed to work alongside dietary changes and physical activity, not replace them. Clean eating complements these medications by ensuring you're consuming nutritious, satiating foods. Your prescriber or GP can advise how to combine medication with dietary changes for best results.
How long does it take to see weight loss results from clean eating?
The NHS recommends expecting gradual results: approximately 0.5 to 1 kg per week with a sustainable calorie deficit. Many people notice changes in energy levels, digestion, and how clothes fit before seeing significant weight loss. Consistency over 4–8 weeks gives the clearest picture of whether your approach is working.
Is clean eating suitable for everyone?
Clean eating is generally suitable for most adults, but individual needs vary. People with specific medical conditions, allergies, or taking certain medications should discuss dietary changes with their GP. Your healthcare provider can personalise clean eating advice based on your health profile and weight management goals.
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.