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
Is Juice Good for Weight Loss?
Most fruit juices are not ideal for weight loss, despite being marketed as healthy. Even 100% natural juices contain high sugar levels and lack the fibre found in whole fruit, which means they don't help you feel full. A small glass of orange juice can contain as much sugar as a fizzy drink. For effective weight loss in the UK, the NHS recommends focusing on whole foods, regular physical activity, and creating a calorie deficit. If you're serious about losing weight, our free GLP-1 weight loss calculator can help you explore evidence-based options and potential outcomes.
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.
Why Juice Isn't Ideal for Weight Loss
Fruit juice is high in natural sugars. A 200ml glass of orange juice contains roughly 18–24g of sugar — equivalent to four teaspoons. Unlike whole oranges, juice removes the fibre, which normally slows sugar absorption and helps you feel satisfied longer.
Liquid calories don't trigger fullness signals. Your brain registers solid food and liquid calories differently. Drinking 200 calories in juice won't make you feel as full as eating 200 calories of solid food, so you're more likely to consume extra calories overall.
Juice spikes blood sugar rapidly. The rapid sugar spike can lead to an energy crash and increased hunger shortly after. This is particularly concerning for those at risk of type 2 diabetes or managing weight-related health conditions in the UK.
- Smoothies can be better than juice if they include whole fruit and protein, but shop-bought versions are often high in sugar
- Vegetable juices like tomato or carrot juice contain fewer natural sugars than fruit juices
- Whole fruits — apples, berries, oranges — provide fibre and are more satiating
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.
Evidence-Based Weight Loss Approaches
The NHS recommends sustainable weight loss through a combination of reduced calorie intake and increased physical activity — aiming for 0.5–1 kg per week. This approach works because it preserves muscle mass and allows long-term adherence.
For those with a BMI of 30 or above, or 27–29.9 with weight-related health conditions, prescription weight loss medications may be an option. Medications like Mounjaro and Wegovy work alongside diet and exercise changes to help reduce appetite. Use our free BMI calculator to check your starting point, and our progress tracker to monitor your weight loss journey over time.
What works best is replacing sugary drinks — including juice — with water, unsweetened tea, or black coffee. Combined with whole foods and regular movement, this creates the sustainable calorie deficit needed for lasting weight loss.
- 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.
Is 100% natural juice better for weight loss than regular juice?
Not significantly. Both contain similar sugar levels — roughly 10–15g per 100ml. The "natural" label doesn't mean low-sugar. Whole fruit is always preferable because the fibre slows digestion and keeps you fuller longer.
Can I drink vegetable juice for weight loss instead of fruit juice?
Vegetable juices are better — they contain far less natural sugar. However, even vegetable juice lacks the fibre of whole vegetables. Eating whole carrots or drinking a vegetable smoothie with the pulp is more effective for weight loss.
What's the difference between juice and smoothies for weight loss?
Smoothies made with whole fruit, yoghurt, and protein powder are superior because they retain fibre and protein, which promote fullness. Shop-bought smoothies are often high in added sugars. Homemade versions with no added sugar are a reasonable alternative to juice.
Does juice affect weight loss efforts on medication like Wegovy?
Yes. Prescription weight loss medications like Wegovy work by reducing appetite, but drinking high-sugar juice counteracts this by spiking blood sugar and creating empty calories. Water, unsweetened tea, and whole foods work better alongside GLP-1 medication.
What should I drink instead of juice for weight loss?
Water is ideal — it has zero calories and supports hydration. Unsweetened tea, black coffee, and sugar-free drinks are good alternatives. If you enjoy flavour, add fresh lemon or mint to water. These choices support weight management without the calorie spike of juice.
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.