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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Best Foods to Eat While Taking Mounjaro
When taking Mounjaro (tirzepatide), choosing the right foods can make a real difference to how you feel and your weight loss progress. Mounjaro works by reducing appetite and helping you feel fuller after smaller meals, but what you eat still matters. This guide covers the foods that work best with Mounjaro, foods to avoid, and practical eating strategies to help you manage side effects and support sustainable weight loss alongside a reduced-calorie diet and increased physical activity.
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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.
Foods That Work Well With Mounjaro
The best foods to eat on Mounjaro are protein-rich, nutrient-dense options that keep you satisfied without aggravating nausea or stomach discomfort. Focus on:
- Lean proteins: Chicken breast, turkey, fish (especially salmon), eggs, and low-fat Greek yoghurt — these digest well and support muscle preservation during weight loss
- Vegetables: Leafy greens, broccoli, carrots, and courgettes — high in fibre and nutrients, low in calories
- Whole grains: Oats, brown rice, and whole wheat bread — provide sustained energy without spiking blood sugar
- Healthy fats: Olive oil, avocados, and nuts — support satiety and cardiovascular health
- Fruits: Berries, apples, and citrus — high in fibre and vitamins, generally well tolerated
Eat slowly, chew thoroughly, and stop when you feel comfortably full. Because Mounjaro slows gastric emptying (how quickly food leaves your stomach), smaller portions eaten mindfully work better than large meals.
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.
Foods to Limit or Avoid on Mounjaro
High-fat and greasy foods often trigger nausea and stomach discomfort when taking tirzepatide. Avoid fried foods, fatty cuts of meat, full-fat dairy, and heavy sauces. Ultra-processed foods — biscuits, crisps, sugary drinks, and takeaways — are high in calories and low in nutrition, working against your weight loss goals. Very spicy foods may irritate your stomach, especially in the first few weeks. Alcohol can worsen nausea and dehydration. If you experience constipation or diarrhoea on Mounjaro, consider temporary adjustments: avoid high-fibre foods temporarily if diarrhoea occurs, or increase fibre gradually if constipated. These side effects often settle as your body adjusts to the 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 should I eat if Mounjaro makes me feel nauseous?
Eat small, frequent meals of bland, easily digestible foods like toast, rice, plain chicken, and mild soups. Avoid fatty and spicy foods. Stay hydrated with water and sugar-free drinks. If nausea persists beyond the first few weeks, speak to your GP or the healthcare professional managing your tirzepatide prescription.
Can I use our GLP-1 weight loss calculator to plan meals on Mounjaro?
Our weight loss calculator can help you estimate your potential weight loss on Mounjaro at different doses, but meal planning is separate. Use the calculator to track your progress and set realistic goals, then adjust your food intake accordingly based on how you feel and your hunger levels.
Do I need to count calories while taking Mounjaro?
Mounjaro works alongside a reduced-calorie diet. Calorie awareness still matters — aim for a sustainable deficit rather than extreme restriction. Because Mounjaro reduces appetite, many people naturally eat fewer calories without strict counting. Your prescriber or a registered dietitian can advise on your specific calorie targets.
Is it safe to eat normal foods on Mounjaro, or must I follow a special diet?
You don't need a special diet, but food choices matter. Focus on whole foods, lean proteins, and vegetables. Avoid ultra-processed, high-fat, and sugary foods — these won't support your weight loss and may trigger side effects. Your GP can refer you to a dietitian for personalised guidance.
How long does nausea from Mounjaro last, and will my food tolerance improve?
Nausea is very common initially but usually improves within the first few weeks as your body adjusts. Most people find they can gradually return to a wider variety of foods. If nausea persists beyond 4–6 weeks or worsens, contact your prescriber — dose adjustment may help.
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.