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
Is Watermelon Healthy For Weight Loss?
Watermelon is a low-calorie, high-water-content fruit that can support weight loss when eaten as part of a balanced diet. With around 30 calories per 100g and 92% water content, watermelon helps you feel fuller for longer without excess energy intake. However, weight loss ultimately depends on overall calorie balance and lifestyle habits. If you're interested in structured weight management support, prescription options like Mounjaro and Wegovy are available in the UK for eligible adults—your GP can assess whether you qualify.
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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.
Watermelon, Calories, and Weight Management in the UK
Watermelon is one of the lowest-calorie fruits available, making it a useful addition to any weight loss UK plan. A typical serving (around 200g) contains just 60 calories but provides significant volume and hydration, which can help reduce overall hunger and food cravings. The high water and fibre content means you're satisfied with fewer calories consumed.
- Calorie content: Approximately 30 calories per 100g
- Hydration benefit: 92% water helps maintain fullness
- Fibre content: Supports digestive health and satiety
- Natural sugars: Fructose present—portion control still matters
While watermelon is nutritious, weight loss requires a consistent calorie deficit. For adults with a BMI weight loss starting point of 27 or above with weight-related health conditions, prescription medication combined with lifestyle changes may be more effective. Use our free BMI calculator above to check your personal weight category and understand your starting point.
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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.
Prescription Weight Loss Options Available in the UK
If you're serious about structured weight management UK, prescription medications offer clinically proven support. The NHS and private providers offer three main options: Mounjaro (tirzepatide), a dual GIP/GLP-1 injection; Wegovy (semaglutide), a GLP-1 injection; and Saxenda, a daily injection. These work alongside dietary changes—not instead of them.
Eligibility includes adults with a BMI of 30 or above, or 27+ with weight-related conditions like type 2 diabetes or high blood pressure. NHS weight loss medication is available through specialist tier 3 services, though waiting times vary by region. Private prescribing is also accessible after online clinical assessment. Try our GLP-1 weight loss calculator to explore potential outcomes at different doses, then speak with your GP about whether prescription support is right for you.
- 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.
Can eating watermelon alone cause weight loss?
No. Watermelon is low-calorie and hydrating, but weight loss requires a consistent calorie deficit across your entire diet and lifestyle. Watermelon works best as part of a balanced eating plan that includes adequate protein, whole grains, and vegetables. Without overall calorie control, watermelon alone won't produce measurable weight loss.
What are the main weight loss injections available in the UK?
Three prescription-only injections are licensed for weight management in the UK: Mounjaro (tirzepatide), which is a dual GIP/GLP-1 agonist; Wegovy (semaglutide), a GLP-1 agonist; and Saxenda (liraglutide), a daily injection. All require a prescription following clinical assessment. Clinical trials show weight loss of 15–21% body weight on average when combined with lifestyle changes.
How do I find out if I'm eligible for prescription weight loss medication on the NHS?
Start by speaking with your GP. You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. Your GP can refer you to a tier 3 specialist weight management service. Waiting times vary by region (ICB). Private prescribing is also available without an NHS referral.
Is watermelon better than other fruits for weight loss?
Watermelon is one of the lowest-calorie fruits, but other options like berries, apples, and pears are equally good. The key is choosing whole fruits over fruit juices (which lack fibre) and eating portion-controlled amounts. All whole fruits support weight loss when part of a calorie-controlled diet—the "best" fruit is the one you'll eat consistently.
Can I use prescription weight loss injections instead of changing my diet?
No. Prescription weight loss medications like Mounjaro and Wegovy work best alongside dietary changes and increased physical activity. They help reduce appetite and support feeling fuller, but they're not replacements for lifestyle changes. The NHS and private prescribers always recommend combining medication with sustainable diet and exercise habits for best results.
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.