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
What Food to Eat While on Mounjaro
When taking Mounjaro (tirzepatide), your appetite naturally decreases and food preferences often change, making it important to choose nutrient-dense foods that support your health and weight loss goals. While there's no special "Mounjaro diet," eating well-balanced meals with adequate protein, fibre, and nutrients helps manage side effects like nausea and diarrhoea, and supports sustainable weight loss alongside your prescription. Understanding how to eat while on this GLP-1 medication can make your treatment more comfortable and effective. Try our free GLP-1 weight loss calculator to see how dietary choices might affect your projected results.
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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.
Best Foods and Eating Strategies on Mounjaro
Mounjaro works by reducing appetite and slowing stomach emptying, so smaller, more frequent meals often work better than large ones. Protein-rich foods — lean chicken, fish, eggs, Greek yoghurt, and legumes — should be a priority, as protein helps preserve muscle during weight loss and keeps you fuller longer.
- Eat soft, easy-to-digest foods early in your treatment, especially if nausea is an issue
- Include plenty of vegetables and wholegrain carbohydrates for fibre, which helps with constipation — a common side effect
- Stay well-hydrated throughout the day, even if appetite is suppressed
- Avoid fatty, greasy, or fried foods, which can trigger nausea and stomach discomfort
- Eat slowly and chew thoroughly — Mounjaro slows digestion, so rushing meals increases discomfort
Unlike Wegovy (semaglutide, a GLP-1 agonist only), Mounjaro's dual GIP and GLP-1 mechanism means some people experience stronger appetite suppression, making portion control easier but requiring intentional nutrient focus.
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.
Foods to Avoid and Individual Adjustments
Foods to limit or avoid: Spicy dishes, high-fat meals, caffeine on an empty stomach, and sugar alcohols (which can worsen diarrhoea). Every person responds differently to Mounjaro — what works for one person may trigger side effects for another.
Your prescriber or a registered dietitian can provide personalised meal planning based on your Mounjaro dose titration schedule and individual health needs. If side effects like nausea or constipation persist, discuss this with your GP or prescriber — they may adjust your dose or recommend specific foods and medications to support your comfort. Use our free BMI calculator and progress tracker to monitor your weight loss and overall health improvements alongside your dietary choices.
- 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.
Can I eat normally while taking Mounjaro?
Most people on Mounjaro can eat normal foods, but in much smaller portions due to reduced appetite. Many find they naturally eat less without feeling deprived. However, choosing nutrient-dense foods helps prevent deficiencies and manages side effects like nausea or constipation more effectively than low-nutrient options.
What's the difference between eating on Mounjaro versus Wegovy?
Both reduce appetite, but Mounjaro's dual GIP and GLP-1 mechanism may produce stronger appetite suppression than Wegovy's single GLP-1 action. Individual responses vary significantly — some Mounjaro users report more severe nausea initially, whilst others tolerate it well. A prescriber can assess which suits you better during clinical assessment.
Should I follow a specific diet while on Mounjaro?
There's no mandatory "Mounjaro diet," but eating balanced meals with lean protein, vegetables, and wholegrains helps manage side effects and supports sustainable weight loss. If nausea, constipation, or other digestive issues occur, a registered dietitian can provide personalised guidance based on your UK prescription and individual tolerances.
Does Mounjaro dose affect what I can eat?
Yes — side effects like nausea often improve as your body adjusts during dose titration. Early doses (2.5–5mg) may require softer, blander foods, whilst higher maintenance doses (10–15mg) may be tolerated better. Your prescriber can advise on adjusting foods based on your specific dose schedule and response.
What if I have persistent nausea while eating on Mounjaro?
Nausea is very common, especially in the first weeks. Try smaller meals, avoid fatty foods, stay hydrated, and eat slowly. If nausea persists beyond the adjustment period, contact your GP or prescriber — they may recommend anti-nausea strategies, adjust your dose, or explore whether Mounjaro is the right fit for you.
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.