icon
Treatmentsicon
Explore options
Our range of treatments are designed to help you lose weight
Discover icon
Mounjaro
21% weight loss treatment
Wegovy
17% weight loss treatment
Saxenda
10% weight loss treatment
Orlos
Weight loss capsules
Programmeicon
How it works
Treatments, coaching and habit change programme
Coaching
The support of a dedicated health coach
Voy app
Track your progress whilst creating healthy sustainable habits
Results
About
Experts
Resourcesicon
Guides & tips
Tools and tips for lasting weight loss
Research & science
Evidence-based insights and clinical research
icon
icon
menu-close
OVERVIEW
Treatment
icon
How it works
icon
Coaching
icon
Voy app
icon
EXPLORE
Results
icon
About
icon
Experts
icon
Resources
icon
ACCOUNT
Login
icon
GET IN TOUCH
020 3912 9885
Mon-Fri 9:00-17:30
icon
Explore options
icon
Mounjaro
icon
Wegovy
icon
Saxenda
icon
Orlos
icon
Guides & tips
icon
Research & science
icon
Home/Guides & Tips/Weight Loss/

Weight loss vs fat loss

What’s the difference between fat loss and weight loss?

The number on the scale doesn’t tell the full story. Here’s why shedding fat (rather than total weight) is what really matters for your health.

clinician image

Medically reviewed by

Dr Earim Chaudry (MBBS), Chief Medical Officer

iconPublished: 3rd April 2025
Research-Based Guide
Table of contents
  • What is weight loss?
  • What is fat loss?
  • Can you lose fat without losin...
  • Key differences between weight...
  • Best ways to measure fat loss ...
  • How to lose fat and maintain m...
  • Your weight loss journey

When trying to lose weight, it’s easy to get hung up on the numbers on the scale. If you’ve been there—we get it, trust us!

But those numbers aren’t the whole story. They measure the total amount of weight lost, not how much fat. And it’s fat loss in particular that’s beneficial for your health.

That’s why fat loss, rather than overall weight loss, can be a more helpful goal to work towards. So, what’s the difference between the two? Read on to find out.

What is weight loss?

Weight loss is the overall reduction in your body weight. It’s a catch-all term that doesn’t distinguish where the dropped weight has come from—that is, whether you’ve lost muscle, fat, or water.

What is fat loss?

On the other hand, fat loss is a reduction in body fat only. It doesn’t include any losses in water or muscle mass.

Ideally, you want to lose fat while preserving muscle. Your muscles play a super important role in keeping you strong and healthy. A drop in lean muscle mass can disrupt your metabolism, lowering the amount of energy your body uses. It can also increase your risk of injury, cause fatigue, and diminish your muscle function.

Reducing your body fat contributes to the health benefits that are associated with weight loss—like a reduced risk of heart disease—without affecting your muscles.

Can you lose fat without losing weight?

Yes, if you’re gaining muscle at the same time. It’s possible for the muscle you build to make up for the weight dropped from lost fat—and therefore, the number on the scale might stay the same.

Key differences between weight loss and fat loss

Now let’s take a deeper look into the differences between losing weight vs losing fat.

Body composition

The two terms refer to different changes in your body composition. Weight loss is the total amount of weight dropped, whether that’s from fat, muscle, or water. Whereas fat loss is specifically referring to the amount of stored fat you’ve lost.

Losing fat takes longer

Most people tend to lose weight quicker at the start of their weight loss programme, usually during the first few weeks. That’s because initially, you’re mostly losing water.

After that, you’ll shift weight more gradually. Fat loss happens at a much slower rate. This is totally normal and doesn’t mean that your plan has stopped working!

Health benefits

We’ve covered this one above, but to give you a quick refresher: Your muscles keep your body working at its best, so it’s better for your health to lose fat while preserving muscle mass.

Appearance

Shedding fat while keeping your muscles intact might also give you a more toned appearance. Whereas with weight loss you might look a bit thinner or smaller in general.

Weight Loss Medications
Learn more about other weight loss treatments to make an informed decision.
icon
Science backed programme
icon
Personalised support
icon
Trusted by 65,000 customers across the UK

Best ways to measure fat loss vs weight loss

But how are you meant to measure fat loss? None of the methods currently used are completely accurate, though they can give you a good idea of how your health and body are changing.

Body measurements

You can do these at home using a tape measure, to keep track of any inches lost around your hips, waist, and thighs. Your waist circumference indicates how much fat is stored around your midsection, while your waist-to-hip ratio (divide waist by hip circumference) is a measure of how much fat is in your waist in relation to your hips.

Body fat percentage

Or you could measure your body fat percentage—that’s how much of your body is made up of fat vs bone and muscle.

A common option here is skinfold calipers, which look sort of like large plastic tweezers. You use the calipers to gently pinch different areas of your body (they will come with instructions that specify where). This will tell you the thickness of the skinfold, and you can use your results to calculate your body fat percentage.

Alternatively, you can buy smart scales that measure your body fat, or visit a specialist healthcare provider for more sophisticated options like DEXA body composition scans.

Strength and fitness improvements

This is perhaps the least precise option of the bunch, but—if you notice that your strength has improved while you’re losing weight, it might be a sign that you’re shedding fat rather than muscle. 

How to lose fat and maintain muscle

So how do you actually do it, then? How do you lose fat while preserving muscle?For one, make sure you’re eating enough protein. It’s essential for building and maintaining muscle. In one review of different studies, eating a diet high in protein led to the most fat loss while sustaining the most muscle, compared to low-carb, low-fat, and high-fibre diets.

It’s also important to hit the gym regularly. Strength training can help preserve your muscles during weight loss. Aim to get two sessions in per week.

And finally, avoid low or very low-calorie diets. These diets may make you lose weight quickly but they’re also linked with greater muscle loss.

Heads up: It’s not healthy to lose weight rapidly and we don’t recommend it. It’s better to go for a moderate reduction in calories and lose weight gradually, while sticking to your diet and exercise routine. Studies show that a gradual approach leads to greater reductions in body fat.

Your weight loss journey

Using scales and measurements to track your progress can definitely be helpful, but what’s most important is how you feel. You’re on a path to being a lighter, happier, healthier you—and we’re so excited for you to reach those goals.

But you don’t have to go through your journey alone. We’re here for you. As part of our weight loss programme, our team of clinicians and coaches will give you personalised advice and guidance along the way. We’ll also post weight loss medication to you each month.

Find out if you’re eligible by filling out this short quiz.

Looking to start you weight loss journey?
Take a quick eligibility quiz to explore your options and see how we can support you.
FAQ

FAQ: Weight loss vs fat loss

Dr Earim Chaudry, MBBS
DisclaimerAt Voy, we ensure that everything you read in our blog is medically reviewed and approved. However, the information provided is not meant to replace professional medical advice, diagnosis, or treatment. It should not be relied upon for specific medical advice.
References
icon¹

Ashtary-Larky, Damoon, et al. “Rapid Weight Loss vs. Slow Weight Loss: Which is More Effective on Body Composition and Metabolic Risk Factors?” International Journal of Endocrinology and Metabolismscribble-underline, vol. 15, no 3, 2017:e13249 https://pmc.ncbi.nlm.nih.gov/articles/PMC5702468/.

icon²

Cava, Edda, et al. “Preserving Healthy Muscle During Weight Loss.” Advances in Nutrition,scribble-underline vol. 8, no. 3, 2017:511-519 https://pmc.ncbi.nlm.nih.gov/articles/PMC5421125/.

icon³

Kreitzman, S.N., et al. “Glycogen Storage: Illusions of Easy Weight Loss, Excessive Weight Regain, and Distortions in Estimates of Body Composition.” The American Journal of Clinical Nutritionscribble-underline, vol. 56, supplement 1, 1992:292S-293S https://pubmed.ncbi.nlm.nih.gov/1615908/.

icon⁴

McCarthy, David, and Berg, Aloys. “Weight Loss Strategies and the Risk of Skeletal Muscle Mass Loss.” Nutrients,scribble-underline vol. 13, no. 7, 2021:2473 https://pmc.ncbi.nlm.nih.gov/articles/PMC8308821/.

icon⁵

Piqueras, Paola, et al. “Anthropometric Indicators as a Tool for Diagnosis of Obesity and Other Health Risk Factors: a Literature Review.” Frontiers in Psychologyscribble-underline, vol. 12, 2021:631179 https://pmc.ncbi.nlm.nih.gov/articles/PMC8299753/.

icon⁶

Willoughby, Darryn, et al. “Body Composition Changes in Weight Loss: Strategies and Supplementation for Maintaining Lean Body Mass, a brief review.” Nutrientsscribble-underline, vol. 10, no. 12, 2018:1876 https://pmc.ncbi.nlm.nih.gov/articles/PMC6315740/

card-image
Weight loss
GLP-1 patches for weight loss
GLP-1 patches claim to help you lose weight. Here’s why you shouldn’t believe the hype.
card-image
Weight loss
Metabolic Age
Metabolic age isn’t an official medical term, but understanding what might impact it could help you reach your health goals.
card-image
Weight loss
How much weight can you lose on Saxenda in a month?
Saxenda affects your body as soon as you start taking it. Here’s what clinical research says about potential weight loss on this daily GLP-1 medication.
card-image
Weight loss
Why Are Obesity Rates Rising in the UK? Key Factors & Insights
Here are some of the different possible factors behind the UK’s increasing obesity rates.
Have a question?
Whatever it is, get in touch:
message
020 3912 9885Mon-Fri 9:00-17:00
message
help@joinvoy.comWe aim to reply in 24hrs
Mon-Fri 9:00-17:00
We aim to reply in 24hrs
Our services are not intended for use in a medical emergency. If you need urgent medical attention, please call 111 or 999

PROGRAMME

  • How it works
  • Treatments
  • Coaching
  • The Voy app

VOY

  • Results
  • About
  • Our medical experts

HELP

  • Help Centre (FAQ)
logo
Privacy PolicyTerms & Conditions
Terms of SaleComplaints
Pharmacies: Manual Pharmacy
Superintendent Pharmacist
Vinisha Kanda
GPhC Registration: 2203475
Copyright 2025 Voy™. All rights reserved.
cards
pharmacy-contact
Privacy Preference Center
We use cookies to help you navigate efficiently and perform certain functions. You will find detailed information about all cookies under each consent category below. The cookies that are categorized as "Necessary" are stored on your browser as they are essential for enabling the basic functionalities of the site. We also use third-party cookies that help us analyse how you use this website, store your preferences, and provide the content and advertisements that are relevant to you. These cookies will only be stored in your browser with your prior consent. You can choose to enable or disable some or all of these cookies but disabling some of them may affect your browsing experience.
Manage Consent Preferences
icon
Necessary Cookies
Always Active
Necessary cookies ensure the basic functionalities of the website, such as security, network management, and accessibility. These cookies cannot be disabled and do not store personal information.
icon
Preferences Cookies
Preferences cookies allow the website to remember information that changes the way the site behaves or looks, such as your preferred language or region.
icon
Statistics Cookies
Statistics cookies help us understand how visitors interact with the website by collecting and reporting information anonymously. These cookies provide insights into metrics such as page visits and traffic sources.
icon
Marketing Cookies
Marketing cookies are used to track visitors across websites. The intention is to display ads that are relevant and engaging for the individual user and more valuable to publishers and third-party advertisers.