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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Healthy Weight Loss Diet Plan Based on BMI
A healthy weight loss diet plan is built on understanding your personal ideal body weight, which the NHS defines as a BMI between 18.5 and 24.9. Rather than following generic diets, the most sustainable approach combines your individual healthy weight range with realistic eating habits and gradual lifestyle change. This guide explains how BMI defines healthy weight, helps you calculate your specific target range, and outlines evidence-based strategies for losing weight at a safe, maintainable pace. Whether you're just starting your weight loss journey or refining your approach, aligning your diet plan with NHS health guidelines gives you the best foundation for long-term success.
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.
Your Healthy Weight Range Based on BMI
According to NHS guidelines, a healthy BMI sits between 18.5 and 24.9, and your specific healthy weight range depends on your height. For example, someone 5ft 8in (173cm) tall has a healthy weight range of approximately 55–74 kg (8st 8lbs to 11st 8lbs). Someone 5ft 4in (163cm) tall should aim for roughly 49–65 kg (7st 10lbs to 10st 3lbs).
You can find your exact healthy weight range using our free BMI calculator on this page — simply enter your height and it will show you the kg and stone range that corresponds to a healthy BMI. This weight for height UK standard is much more personal than a one-size-fits-all diet, because it accounts for your individual frame and biology.
Important: BMI does not account for muscle mass or where fat is stored. Your GP can provide additional context about whether your current weight poses health risks specific to you.
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.
Building Your Healthy Weight Loss Diet Plan
A safe, sustainable diet plan typically creates a calorie deficit of around 500 kcal per day, which supports weight loss of approximately 0.5–1 kg per week — the NHS recommended rate. This means you can expect to reach your ideal weight range over several months rather than weeks, which dramatically improves the chance of keeping the weight off.
Key elements of a healthy weight loss diet plan include: eating plenty of vegetables and lean protein, staying hydrated, reducing sugary drinks and processed foods, and choosing whole grains over refined carbohydrates. Combining dietary changes with increased physical activity — even just 150 minutes of moderate activity per week — significantly improves results and overall health.
Track your progress using our free progress tracker, and use the BMI calculator regularly to monitor how your weight loss moves you toward your healthy weight range.
- 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 is the difference between ideal body weight and a healthy BMI?
Ideal body weight is a target weight calculated using formulas (like Devine or Robinson), whilst a healthy BMI simply means a BMI between 18.5 and 24.9, regardless of exact kg. For most people, being within the healthy BMI range is the most practical target. Your GP can help clarify which matters most for your individual health.
How do I know what my healthy weight range is for my height?
Use our free BMI calculator on this page — enter your height and it will instantly show you the kg and stone range that corresponds to a healthy BMI (18.5–24.9). This is your personalised healthy weight range based on NHS guidelines. The weight converter tool can also help you switch between metric and imperial units.
Can I lose weight faster than 0.5–1 kg per week?
Faster weight loss is possible, especially with medical support, but the NHS recommends 0.5–1 kg per week for sustainable results. Losing weight too quickly increases muscle loss and is harder to maintain long-term. If you've struggled with dieting or have medical conditions, your GP can discuss faster options with appropriate support.
What should my daily calorie intake be for healthy weight loss?
This depends on your age, sex, current weight, and activity level. A general guideline is creating a deficit of 500 kcal/day (roughly 0.5 kg/week loss), but individual needs vary widely. Your GP, a registered dietitian, or a weight management service can calculate your personal calorie target.
Does diet alone work, or do I need to exercise?
Diet is the primary driver of weight loss, but combining diet with physical activity produces better long-term results and supports heart health, muscle preservation, and mood. Aim for at least 150 minutes of moderate activity per week alongside dietary changes. Start with whatever activity you enjoy and can sustain.
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.