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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Carbohydrates and Weight Loss: A UK Guide to Making Smarter Food Choices
Carbohydrates are an essential macronutrient, but choosing the right types can support your weight loss goals. Not all carbohydrates affect your body the same way — whole grains, vegetables, and legumes release energy slowly and keep you fuller longer, while refined carbs may leave you hungry sooner. This guide explains which carbohydrate foods support weight management in the UK, and how they fit alongside other proven approaches like increased physical activity and, where appropriate, prescription weight loss medication available through the NHS or private prescribing.
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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.
Understanding Carbohydrates and Weight Loss Options in the UK
When managing your weight in the UK, carbohydrate choices matter. Low glycaemic index (GI) carbohydrates — such as oats, brown rice, sweet potatoes, and lentils — release energy gradually, helping you feel satisfied for longer. High GI carbohydrates — white bread, sugary drinks, and processed snacks — cause rapid blood sugar spikes followed by crashes that increase hunger and cravings.
- Whole grains: oats, barley, wholemeal bread, quinoa
- Vegetables: broccoli, spinach, carrots, peppers (unlimited portions)
- Legumes: beans, lentils, chickpeas (high in fibre and protein)
- Fruits: apples, berries, oranges (in moderate portions)
For many people, carbohydrate management alone may not be enough for meaningful weight loss. If you have a BMI of 30 or above (or 27 or above with weight-related health conditions), prescription weight loss medication such as Mounjaro (tirzepatide) or Wegovy (semaglutide) may be available to you in the UK. These GLP-1 medications work alongside dietary changes to support weight management. Use our free BMI calculator above to check where you stand, and our GLP-1 weight loss calculator to see how medication might support your goals.
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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 and Prescription Options Available in the UK
The NHS recommends a balanced approach to weight management that includes healthy carbohydrate choices, reduced portion sizes, and increased physical activity. If lifestyle changes alone aren't delivering results, prescription weight loss treatment is available through two main routes in the UK. NHS specialist weight management services (tier 3) may prescribe medications like Mounjaro or Wegovy for eligible adults, though waiting times vary significantly by region. Private online prescribing is also available — following a clinical assessment with a UK-licensed prescriber, these medications can be dispensed by GPhC-registered pharmacies without an NHS referral. Your GP can advise whether prescription weight loss treatment might be suitable for you based on your individual health, BMI, and weight-related conditions.
- 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.
Are low-carb diets better than balanced carbohydrate intake for weight loss?
Both low-carb and balanced carbohydrate approaches can support weight loss — what matters most is maintaining a calorie deficit and sticking to your chosen approach long-term. Evidence suggests that for most people, a balanced diet including whole-grain carbohydrates is sustainable and supports overall health. Your GP can advise on the best approach for your individual circumstances.
How do prescription weight loss injections like Mounjaro fit with carbohydrate choices?
Mounjaro and Wegovy work by reducing appetite and helping you feel fuller with smaller portions — they're designed to work alongside dietary changes, not replace them. Making smart carbohydrate choices (whole grains, vegetables, legumes) complements the medication's effects and supports sustainable weight management.
Can I access Mounjaro or Wegovy through the NHS in the UK?
Yes, both Mounjaro (tirzepatide) and Wegovy (semaglutide) are NHS-approved for weight management in eligible adults. Access is through specialist tier 3 weight management services — your GP can refer you. Private prescribing is also available. Eligibility typically requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions.
What is the recommended rate of weight loss for safety?
The NHS recommends losing no more than 0.5–1 kg (1–2 lbs) per week for sustainable, healthy results. This rate helps preserve muscle mass and makes weight loss easier to maintain long-term. Prescription weight loss medication may support faster initial results, but should always be combined with lifestyle changes.
Should I try carbohydrate reduction before considering prescription medication?
Many people benefit from trying dietary and activity changes first — your GP can discuss this with you. However, if you have a BMI of 27 or above with weight-related health conditions (such as type 2 diabetes or high blood pressure), you may be eligible for prescription treatment now, without waiting. A prescriber can assess what's right for your individual situation.
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.