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
Diet Plan For Weight Loss UK — What Works
A successful diet plan for weight loss in the UK combines sustainable eating habits with realistic goals. The NHS recommends losing weight at a rate of 0.5 to 1 kg per week, which requires a calorie deficit of roughly 500 kcal per day. There's no single "best" diet — effectiveness depends on finding an approach you can stick with long-term. Whether through calorie counting, portion control, or structured meal planning, the key is consistency alongside increased physical activity. Use our free BMI calculator to establish your starting point and healthy weight range for your height.
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.
Popular UK-Approved Diet Approaches
Several evidence-based diet methods are popular in the UK and recommended by healthcare professionals for sustainable weight management UK:
- Calorie deficit method: Track daily intake to create a 500 kcal deficit, typically resulting in 0.5 kg weekly loss. Our weight converter and BMI calculator help you determine your target range.
- Mediterranean diet: Emphasises olive oil, fish, vegetables, and whole grains. Strong evidence supports cardiovascular health and sustained weight loss.
- Low-carbohydrate approach: Effective short-term but long-term results are similar to standard calorie restriction. Works well for some individuals.
- Intermittent fasting (16:8 or 5:2): Restricts eating windows or calories on specific days. Evidence suggests modest weight loss comparable to continuous calorie restriction.
- NHS Weight Loss Plan: Free structured 12-week programme available online. Includes food tracking, recipes, and activity logging.
Prescription weight loss medication NHS services may also be recommended alongside dietary changes for eligible adults.
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.
Creating Your Personal Diet Plan
Start by calculating your calorie maintenance level — roughly your body weight in kg multiplied by 22–25, depending on activity. A deficit of 500 kcal daily supports lose weight uk goals of approximately 0.5 kg weekly. Set realistic targets: aim for 5–clinically studied weight loss initially, which delivers meaningful health benefits including improved blood pressure and blood sugar control.
Include protein with every meal to support muscle retention during weight loss. Stay hydrated, plan meals ahead to avoid impulsive choices, and track progress using our free progress tracker. Work with your GP if you have health conditions, take medications, or aren't losing weight after 3–4 weeks of consistent effort. For eligible adults, glp-1 weight loss options like Mounjaro or Wegovy may be discussed with your GP as part of your overall weight management strategy.
- 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 a realistic diet plan for weight loss in the UK?
The NHS recommends a calorie deficit approach creating roughly 500 kcal daily reduction, targeting 0.5–1 kg weekly loss. Combine this with increased physical activity and sustainable eating habits. Popular methods include the Mediterranean diet, intermittent fasting, or simple calorie counting. The best plan is one you can maintain long-term rather than a restrictive short-term approach.
How do I calculate my daily calorie target?
Estimate your maintenance calories roughly as your body weight (kg) × 22–25, depending on activity level. Subtract 500 kcal to create your weight loss target. Use our BMI calculator to find your healthy weight range for your height, which helps set realistic long-term goals. Adjust targets based on progress every 3–4 weeks.
Can I lose weight without counting calories?
Yes. Portion control, eating slowly, prioritising protein and vegetables, and avoiding sugary drinks all support weight loss without formal calorie tracking. The NHS Weight Loss Plan uses this approach. However, many people find tracking initially helpful to understand eating patterns. Track for a few weeks to learn portion sizes, then switch to intuitive eating if preferred.
How does prescription weight loss medication fit into a diet plan?
Prescription medications like Mounjaro or Wegovy are not replacements for diet and exercise but work alongside them. They may help reduce appetite and support feeling fuller after meals. Access through NHS specialist weight management services or private prescribing requires clinical assessment. Always combine medication with sustainable dietary changes and activity for best results.
What if I'm not losing weight after following a diet plan?
Review your calorie deficit — weight loss may be slower than expected if the deficit is smaller than calculated. Ensure accuracy in tracking if counting calories. Consider increased physical activity, stress management, and sleep quality, as these affect weight loss. If you've tried consistently for 3–4 weeks without progress, speak to your GP to check for underlying health conditions.
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.