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
Eating Plan for Weight Loss — What Works
An effective eating plan for weight loss starts with understanding how calorie deficit drives sustainable results. In the UK, the NHS recommends losing weight at a rate of 0.5 to 1 kg per week — achievable through a combination of dietary changes and increased physical activity. Whether you're managing your weight management journey alone or alongside prescription weight loss medication, the right eating plan gives you structure, clarity, and the best chance of success. This guide covers evidence-based nutrition strategies backed by UK health guidance.
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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.
How to Build an Eating Plan for Weight Loss
The foundation of any eating plan is calorie deficit — consuming fewer calories than your body burns. A deficit of approximately 500 kcal per day typically results in losing around 0.5 kg per week. This doesn't mean extreme restriction; sustainable weight loss comes from modest changes you can maintain.
- Balanced macronutrients: Include protein (chicken, fish, eggs, legumes), whole grains, and plenty of vegetables. Protein supports muscle retention and keeps you fuller longer.
- Portion control: Use smaller plates, measure portions, and be mindful of liquid calories (sugary drinks, alcohol, oils).
- Meal planning: Prepare meals in advance to avoid impulsive, high-calorie choices. Simple batch cooking on weekends works well.
- Consistency over perfection: One indulgent meal won't derail progress — consistency across weeks and months matters most.
If you're taking prescription weight loss medication like GLP-1 injections, your eating plan becomes even more important. These medications help reduce appetite, but you still need nutritious, appropriately-sized meals to support your health and maximise weight loss results.
Clinically BackedWeight Loss
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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.
NHS Weight Loss Guidance and Medical Support
The NHS recommends a low-calorie diet of 1,200–1,500 kcal per day for women and 1,500–1,900 kcal for men as a sustainable starting point. Very low-calorie diets (under 800 kcal daily) should only be followed under medical supervision and typically last 12 weeks maximum.
For weight management in the UK, a structured approach works best. Your GP can refer you to tier 3 specialist weight management services, where you'll receive personalised guidance. Many people also benefit from tracking tools — use our free BMI calculator above to understand your starting point, and our progress tracker to log your eating plan results week by week.
Consider discussing whether prescription weight loss support might help you. Our GLP-1 weight loss calculator can show potential results when lifestyle changes are combined with medication.
- 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 best eating plan for quick weight loss?
The NHS recommends losing 0.5–1 kg per week for sustainable, healthy results. "Quick" diets often fail because they're too restrictive. A moderate calorie deficit (500 kcal/day) combined with regular activity produces steady, long-term success. gradual weight management risks muscle loss and is harder to maintain.
Can I use an eating plan with prescription weight loss injections?
Yes — absolutely. Medications like Wegovy (semaglutide) work best alongside a structured eating plan and physical activity. The medication helps control appetite, but you still need nutritious meals. Your prescriber and GP can advise on combining your eating plan with any medication.
How many calories should my eating plan include daily?
The NHS suggests 1,200–1,500 kcal/day for women and 1,500–1,900 kcal for men as a sustainable starting point. Individual needs vary by age, activity level, and metabolism. Your GP can give personalised guidance, or a registered dietitian can create a plan tailored to your health.
What foods should I avoid in a weight loss eating plan?
Focus on reducing, not eliminating: sugary drinks, pastries, takeaways high in salt/fat, and alcohol (very calorie-dense). These don't need to be forbidden — moderation is key. Instead, prioritise vegetables, lean protein, whole grains, and home-cooked meals you can control.
Should I count calories in my eating plan?
Calorie awareness helps most people lose weight successfully. You don't need to obsess over exact numbers, but understanding portion sizes and calorie content of common foods is useful. Apps, food labels, and nutrition websites make this easy. Some people prefer focusing on food quality instead — discuss what suits you with your GP.
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.