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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Free Diet Planner For Weight Loss — What Works in the UK
A free diet planner can be a valuable starting point for weight loss, but the most effective approach combines dietary changes with sustainable lifestyle habits. In the UK, the NHS recommends a calorie deficit of around 500 kcal per day to achieve a safe weight loss rate of 0.5 to 1 kg per week. Whether you're managing your weight through diet alone or considering weight management options, understanding the fundamentals of nutrition and calorie control is essential. This guide explains how to approach diet planning, what the evidence shows about different methods, and how prescription weight loss support may complement your efforts.
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.
How Diet Planning Supports Weight Loss
A diet plan helps you become aware of what you eat, identify patterns, and make intentional choices aligned with your health goals. Free diet planners typically work by:
- Recording daily food and drink intake
- Tracking calories or macronutrients (protein, carbohydrates, fat)
- Setting realistic targets based on your height, weight, and activity level
- Providing feedback on progress over weeks and months
The NHS weight loss plan recommends a calorie deficit for sustainable weight loss. For most adults, this means reducing intake by approximately 500 kcal daily, which typically results in losing around 0.5 kg per week. A low calorie diet of 800–1200 kcal per day can achieve faster results but should only be followed under medical supervision. You can use our free BMI calculator above to establish your current weight status and healthy weight range, then work backward to determine an appropriate calorie target with your GP or a dietitian.
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.
Creating an Effective Diet Plan — Practical Steps
Start with these evidence-based steps: First, calculate your daily calorie needs using a free online calculator, then subtract 500 kcal to create a modest deficit. Focus on whole foods—vegetables, fruits, lean proteins, and whole grains—rather than restrictive elimination diets. Keep a simple food diary or use a free app to log meals; research shows that tracking increases accountability and awareness. Drink adequate water, get enough sleep, and incorporate physical activity gradually. If you find that diet and exercise alone are not delivering results after several months, discuss prescription weight management options with your GP. For eligible adults, GLP-1 weight loss injections like Mounjaro or Wegovy are available through NHS weight management services or private prescribing, and they work best when combined with continued dietary improvements and activity changes. Our free GLP-1 weight loss calculator can help you explore potential outcomes if medication becomes relevant to your journey.
- 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.
Is a free diet planner enough for weight loss?
A free diet planner is an excellent starting tool that helps with awareness and accountability. However, sustainable weight loss typically requires combining dietary changes with increased physical activity, adequate sleep, and stress management. For some people, this approach is sufficient; for others, prescription weight management medications alongside diet support better outcomes.
How many calories should I eat to lose weight?
The NHS recommends a calorie deficit of around 500 kcal per day for a safe loss rate of 0.5–1 kg weekly. Your personal target depends on your current weight, height, age, and activity level. A GP or registered dietitian can give you personalised advice. Use our free BMI calculator to establish your healthy weight range, then calculate backwards to your target calorie intake.
What if diet and exercise don't work?
If you've followed a structured diet plan for several months without sufficient results, discuss your options with your GP. For adults with a BMI of 30 or above, or BMI 27+ with weight-related health conditions, prescription weight loss medication may be appropriate. These medicines are used alongside continued diet and exercise changes, not instead of them.
Are free diet apps as good as paid ones?
Many free diet and calorie-tracking apps are evidence-based and highly effective. The best app is one you'll use consistently. Free options like MyFitnessPal, Lose It, or the NHS Weight Loss Plan app all provide reliable calorie tracking. Consistency matters more than which platform you choose.
How does GLP-1 weight loss medication fit with a diet plan?
GLP-1 medications like Mounjaro and Wegovy are prescribed-only injections that help reduce appetite and support feeling fuller after meals. They work best when combined with continued healthy eating and physical activity—not as a replacement for diet changes. Clinical trials showed average weight losses of 15–21% over a year when medication was paired with lifestyle modifications.
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.