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
Best Foods for Gut Health and Weight Loss
A healthy gut supports sustainable weight loss. The foods you eat directly affect your digestive health, metabolism, and how your body manages weight. This guide covers the best foods for gut health backed by NHS and scientific evidence, helping you make informed choices whether you're starting a weight management UK programme or supporting prescription weight loss with lifestyle changes. A strong digestive system also works better with GLP-1 weight loss medication if you're considering that option.
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.
Foods That Support Gut Health and Weight Management
Fibre-rich foods are the foundation of good gut health and sustainable weight loss. Soluble fibre (found in oats, beans, lentils, and apples) feeds beneficial gut bacteria and helps you feel fuller for longer. Aim for at least 30g of fibre daily — most UK adults consume only 18g. Fermented foods like natural yoghurt, kefir, sauerkraut, and kimchi introduce live beneficial bacteria (probiotics) that improve digestive function. Whole grains (brown rice, quinoa, wholemeal bread) provide sustained energy and support stable blood sugar levels, reducing cravings.
- Leafy greens (spinach, kale, broccoli) are low-calorie, nutrient-dense, and excellent for gut bacteria
- Berries (blueberries, blackberries) contain polyphenols that feed healthy gut bacteria
- Fatty fish (salmon, mackerel) provide omega-3s that reduce inflammation and support weight management
- Nuts and seeds (almonds, flaxseeds, chia seeds) deliver fibre, healthy fats, and satiety
These foods work alongside nhs weight loss principles and prescription weight loss medication by supporting your body's natural satiety signals and digestive efficiency.
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.
Practical Tips for Gut-Friendly Weight Loss Eating
Start by increasing water intake — aim for 2 litres daily to support digestion and reduce false hunger. Introduce high-fibre foods gradually to avoid bloating, allowing your gut bacteria to adapt over 1–2 weeks. Eat slowly and mindfully: chewing thoroughly gives your brain time to register fullness signals, which is especially helpful if you're using prescription weight loss injections like Wegovy or Mounjaro.
- Plan meals with a protein source (lean meat, tofu, eggs, legumes) at each meal for sustained fullness
- Limit ultra-processed foods, added sugars, and excessive salt — they harm gut bacteria and trigger weight gain
- Keep portion sizes balanced: fill half your plate with vegetables, one quarter with whole grains, one quarter with protein
Track your progress with our free progress tracker to monitor how dietary changes affect your weight and energy levels over time. Most sustainable weight loss occurs at 0.5–1 kg per week.
- 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 link between gut health and weight loss?
A healthy gut microbiome regulates hunger hormones, supports metabolism, and improves digestion. Beneficial gut bacteria help extract nutrients efficiently and produce short-chain fatty acids that reduce inflammation and support weight management. Poor gut health leads to cravings, sluggish metabolism, and difficulty losing weight.
How much fibre should I eat daily for weight loss?
The NHS recommends 30g of fibre daily for most UK adults. Fibre keeps you feeling fuller longer, stabilises blood sugar, and feeds beneficial gut bacteria. Increase your intake gradually over 1–2 weeks (oats, beans, whole grains, vegetables, fruit) to avoid bloating and allow your digestive system to adapt.
Can gut-healthy foods help with prescription weight loss medication?
Yes. Foods that support gut health complement prescription weight loss injections like Wegovy (semaglutide) or Mounjaro (tirzepatide) by enhancing satiety signals, reducing bloating, and maintaining stable energy. Fibre and fermented foods are particularly beneficial when using GLP-1 weight loss medication.
Are fermented foods like yoghurt essential for weight loss?
Fermented foods aren't essential but are beneficial. Natural yoghurt, kefir, sauerkraut, and kimchi introduce live beneficial bacteria that improve digestion, reduce inflammation, and support weight management. Include them if you enjoy them, but regular vegetables and whole grains are equally important.
How do I check if my weight is healthy for my height?
Use our free BMI calculator above to check your personal BMI — the NHS healthy range is 18.5 to 24.9 for most adults, or 18.5 to 22.9 for South Asian, Chinese, Black African, or Caribbean adults. Your GP can also give personalised guidance based on your individual health.
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.