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
Best Nutrition Plan for Weight Loss
There's no single "best" nutrition plan for weight loss — the most effective approach is one you can sustain long-term. However, evidence shows that any plan creating a consistent calorie deficit, combined with regular physical activity and behavioural support, can help you lose weight successfully. The NHS recommends aiming for a loss of 0.5 to 1 kg per week for sustainable results. Your personal nutrition plan should fit your lifestyle, preferences, and health conditions. This guide explores evidence-based approaches that work for weight management in the UK.
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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.
Evidence-Based Nutrition Approaches for Weight Loss
Calorie deficit is the foundation of all weight loss. To lose approximately 0.5 kg per week, you need a deficit of around 500 kcal per day — achieved through eating less, moving more, or both. Use our free BMI calculator above to check your current weight status and establish a baseline.
Popular UK nutrition approaches include:
- Mediterranean diet: Emphasis on plant-based foods, healthy fats, lean proteins. Strong evidence for heart health and sustainable weight loss.
- Low-carbohydrate diet: Effective short-term, though long-term results are similar to standard calorie restriction.
- Intermittent fasting (16:8 or 5:2): Evidence suggests modest weight loss comparable to regular calorie restriction.
- NHS Weight Loss Plan: Structured, free UK programme combining dietary guidance, activity targets, and behaviour change support.
The best plan is one you'll stick to consistently. Work with your GP or a registered dietitian to choose an approach aligned with your health needs.
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.
Combining Nutrition with Other Weight Loss Support
Nutrition alone is most effective when paired with regular physical activity — even moderate exercise like brisk walking 150 minutes weekly supports weight loss and health. Behaviour change support, through apps, group programmes, or one-to-one coaching, significantly improves long-term success rates.
For some adults, prescription weight loss medication may be recommended as part of a comprehensive approach. Options include GLP-1 weight loss injections available through NHS weight management services or private prescription. These work alongside, not instead of, dietary changes. Try our free GLP-1 weight loss calculator to understand how prescription options might support your personal weight management journey. Track your progress using our free progress tracker to monitor both weight and dietary consistency over time.
- 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's the fastest safe rate of weight loss?
The NHS recommends losing 0.5 to 1 kg per week for sustainable results. This typically requires a calorie deficit of around 500 kcal per day. Faster loss increases the risk of muscle loss, nutritional deficiencies, and rebound weight gain. Consult your GP before attempting more gradual weight management.
Do I need to follow a specific diet plan to lose weight?
No. Any eating pattern that creates a consistent calorie deficit can work. The "best" plan is one you enjoy and can maintain long-term. Mediterranean, low-carbohydrate, intermittent fasting, and standard calorie restriction all show similar long-term results when calories are equal.
How does the NHS approach nutrition for weight management?
The NHS Weight Loss Plan combines calorie reduction (typically 600 kcal deficit), increased activity (150 minutes weekly), and behaviour change support. It's available free to eligible adults through their GP or as a self-guided digital programme.
Can nutrition alone achieve weight loss, or do I need exercise too?
Nutrition creates weight loss; exercise enhances results and supports overall health. For best outcomes, combine a calorie deficit with regular activity and behaviour change support. This combination improves cardiovascular health, mood, and long-term success rates.
What role do weight loss medications play in a nutrition plan?
Prescription weight loss medications like GLP-1 injections are used alongside, not instead of, nutrition and activity changes. They may help reduce appetite and support fuller feelings on smaller portions. Access in the UK is through NHS weight management services or private prescription following clinical assessment.
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.