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
Does Stress And Anxiety Cause Weight Loss?
Yes, stress and anxiety can cause weight loss in some people, though the effect varies significantly between individuals. When you're stressed or anxious, your body releases hormones like cortisol and adrenaline that can suppress appetite, increase metabolism, and trigger physical symptoms like nausea or a tight stomach. However, stress affects everyone differently—some people lose weight whilst others gain weight during stressful periods. If you've noticed unexplained weight loss alongside anxiety or stress, it's worth discussing with your GP, especially if it's affecting your health or wellbeing.
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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.
How Stress And Anxiety Affect Your Body Weight
Stress hormones (cortisol and adrenaline) activate your body's "fight or flight" response, which can reduce appetite and increase calorie burn temporarily. This is why many people report eating less when anxious or worried. However, prolonged stress can also trigger emotional eating or comfort eating, leading to weight gain instead. The relationship between stress and weight loss depends on how your individual body responds and how long the stress lasts.
- Short-term stress: often suppresses appetite and may cause weight loss
- Chronic stress: cortisol elevation can increase belly fat storage and cravings for high-calorie foods
- Sleep disruption: anxiety often leads to poor sleep, which impacts metabolism and hunger hormones
- Nausea and digestive issues: anxiety can cause stomach upset, reducing food intake
For sustainable weight management in the UK, explore evidence-based approaches through NHS weight loss services or speak to your GP about personalised strategies. If stress-related weight changes persist, your GP can rule out underlying medical conditions.
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.
When To Seek Help From Your GP
Unexplained weight loss—especially when combined with anxiety, stress, or other symptoms—warrants a GP appointment. Your doctor can assess whether weight changes are stress-related or indicate an underlying medical condition such as thyroid issues, depression, or digestive problems. If you're struggling with stress or anxiety affecting your eating and weight, your GP can refer you to mental health support or specialist services.
- Weight loss of more than 5% body weight in a short period
- Persistent anxiety or panic symptoms lasting weeks
- Loss of appetite alongside other physical symptoms
- Sleep problems or emotional distress
Using our free BMI calculator and progress tracker can help you monitor your weight trends and identify patterns linked to stress. This information is valuable to share with your GP during an appointment.
- 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 anxiety alone cause significant weight loss?
Anxiety can suppress appetite and increase metabolism temporarily, leading to weight loss in some people. However, the degree of weight loss varies greatly between individuals. If you're experiencing persistent weight loss alongside anxiety, speak to your GP to rule out other causes.
Why does stress make some people lose weight and others gain?
Stress hormones suppress appetite in some people (leading to weight loss), whilst others respond with emotional eating or comfort-seeking behaviour (leading to weight gain). Genetics, personality, and stress coping mechanisms all influence how stress affects your weight.
Is stress-related weight loss dangerous?
Rapid or unexplained weight loss can indicate stress, anxiety, or an underlying health condition. If you've lost more than 5% of your body weight unintentionally, contact your GP. They can assess your health and provide appropriate support.
How long does stress-related weight loss typically last?
Short-term stress often causes temporary appetite suppression and weight loss that reverses when stress reduces. Chronic or ongoing stress may cause longer-term weight changes. Managing stress through relaxation, exercise, and professional support helps stabilise weight.
Should I be worried about weight loss during an anxious period?
Some weight loss during stressful periods is common and often reverses naturally. However, if weight loss is rapid, unexplained, or accompanied by other concerning symptoms, contact your GP. They can provide reassurance and rule out medical conditions.
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.