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 Does a BMI of 35 Mean?
A BMI of 35 falls into the obese category according to NHS guidelines. This means your weight poses an increased risk to your health, and your GP may recommend action to reduce health-related complications. The good news is that even modest weight loss—as little as 5 to 10 per cent of your body weight—can bring meaningful health improvements. Understanding your BMI range and what it means for you is the first step toward making healthier choices. Use our free BMI calculator above to check your personal BMI and see how it compares to NHS thresholds.
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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.
NHS BMI Categories and Your Health
According to NHS guidance, BMI is categorised into ranges that help assess health risk. A BMI of 35 places you in the obese (Class II) category, which the NHS defines as BMI 35.0–39.9. This indicates that your weight is likely affecting your health and increasing your risk of weight-related diseases.
- Healthy BMI: 18.5–24.9 (lowest health risk)
- Overweight: 25.0–29.9 (moderate health risk)
- Obese Class I: 30.0–34.9 (higher health risk)
- Obese Class II: 35.0–39.9 (significantly higher health risk)
- Severely obese: 40.0+ (very high health risk)
If you're of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds, as these groups face higher health risks at lower BMI levels. For these populations, a healthy BMI range is 18.5–22.9 rather than 18.5–24.9.
It's important to remember that BMI limitations exist—BMI does not distinguish between muscle and fat, so athletes or very muscular individuals may have a high BMI without excess fat. Your GP can provide personalised guidance based on your full health picture, including waist circumference and overall fitness level.
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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 Management Support and Next Steps
If your BMI is 35, your GP may suggest that you would benefit from support to manage your weight. The NHS weight management pathway typically starts with self-help and lifestyle changes: a balanced diet, increased physical activity, and behaviour change strategies. Many people find success through the NHS Weight Loss Plan or local community weight management programmes available in your area.
For more structured support, you may be referred to a specialist weight management service (tier 3), where you can access personalised dietary advice, exercise programmes, and potentially prescription weight loss medication if clinically appropriate. These specialist services are free on the NHS but availability varies by region. Track your progress using our free progress tracker to stay motivated and see how small changes add up over time.
- 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 health risks are associated with a BMI of 35?
A BMI of 35 significantly increases your risk of type 2 diabetes, heart disease, high blood pressure, stroke, certain cancers, sleep apnoea, and joint problems. The good news is that losing even 5–10 per cent of your body weight can reduce these risks substantially and improve your overall health markers.
What does the NHS recommend if my BMI is 35?
The NHS recommends lifestyle changes as the first step: eating a balanced, lower-calorie diet and increasing physical activity. Your GP may also refer you to a weight management programme, community support group, or specialist weight management service. In some cases, prescription weight loss medication may be considered alongside lifestyle changes.
Can I use the BMI formula to check my own BMI?
Yes. The standard BMI formula is: BMI = weight (kg) ÷ height (m)². For example, if you weigh 90kg and are 1.73m tall, your BMI is 90 ÷ (1.73)² = approximately 30.1. Our free BMI calculator above does this calculation instantly and shows you which NHS category you fall into.
How can I start losing weight with a BMI of 35?
Start with small, sustainable changes: reduce portion sizes, choose whole foods, drink more water, and aim for 150 minutes of moderate physical activity per week. A calorie deficit of around 500 kcal per day typically results in about 0.5kg weight loss per week. Contact your GP for personalised advice and support options available in your area.
What's the difference between BMI categories for different ethnic groups?
The NHS recognises that South Asian, Chinese, Black African, and Black Caribbean adults develop health conditions at lower BMI levels than other populations. For these groups, a healthy BMI is 18.5–22.9 (not 18.5–24.9), and overweight starts at 23.0. Your GP can discuss which thresholds are most relevant to your 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.