How to improve your body composition 

There’s much more to it than ‘simply’ losing weight.

It’s easy to fall into the trap of wanting to lose weight, without truly understanding what we mean by that. For most of us, when we say we want to lose weight, what we probably mean is that we want to reduce the amount of body fat we are carrying, without necessarily losing any of our muscle mass. This means that the goal is to improve our body composition. 

Improving your body composition brings a host of potential health benefits with it. And in many ways, it’s a better, more comprehensive view of your health and fitness than simply looking at your weight or measuring your body mass index.

We’ll introduce some of the main factors you need to be thinking about, if better body composition is your goal. 

An older man with a flowing white beard flexing his muscles on the beach at sunsetCredit: Shutterstock/NeonShot

What does it mean to improve body composition?

For most, it’s about building muscle and reducing body fat

Body composition breaks down your weight into its constituent parts – it can tell you how much of your weight is fat, muscle, water or bone, for example. As a result, it is a more detailed insight into what’s happening in your body than weight alone can tell you. 

The body composition screens on the Withings HealthMate appCredit: Saga Exceptional

To improve body composition, we want to change the amount of each of these metrics in a positive way. For most of us, this will probably mean reducing our body fat percentage, and increasing our muscle mass – this is what we’ll primarily focus on in this article. But it’s worth mentioning that ‘improved’ body composition may not mean this for everyone. Some people may be looking to put on a bit of weight, for example.  

If you want to feel fitter, reduce the risk of certain health problems, and generally have a more independent lifestyle (especially as we age) then improving your body composition may be a goal worth pursuing.  

How to improve body composition

There are a lot of influences

There are many factors that can influence your body composition. They broadly fit under the following categories: 

What we eat, and how much, can profoundly affect body composition

Some types of exercise will be more impactful than others at changing body composition 

Sleep is crucial for supporting recovery from exercise and hormone regulation

Stress can have a surprising impact on your body composition

Let’s look at each of these topics in a little more detail, to try to understand how they can help change your body composition.  


Food can fundamentally influence body composition

A table covered in a variety of healthy foods, such as broccoli, salmon, nuts and seeds, and fruit.Credit: Shutterstock/margouillat photo

Most of us have probably heard the saying, “you are what you eat”. And while none of us (that we know of) has turned into a biscuit, the food we consume does have a considerable influence on our body composition. Just as important, how much we eat also matters.

As Dr Sunni Patel – a wellness and lifestyle medicine coach with a PhD in risk factors for disease, and 15 years of healthcare experience – says:What we eat plays a crucial role in improving body composition.” 

Calories in vs calories out

At its most basic, your weight is influenced by whether you eat more calories than your energy needs, or fewer. 

Dr Patel tells us: “Consuming an appropriate number of calories is essential. If you consume more calories than your body needs, you may gain weight in the form of fat. Conversely, consuming fewer calories than your body needs can lead to weight loss, including muscle loss. Balancing your caloric intake with your energy expenditure is vital for maintaining or improving body composition.” 

It’s important to remember that your body needs a minimum amount of energy to carry out the essential functions that keep us alive – known as your basal metabolic rate, or BMR. Your BMR is a useful way to get an idea of how many calories you need each day to maintain your current weight. You can then use that number as a guideline. 

Tips for maintaining a calorie deficit: 

  • Slow down when you eat. Studies have found that a slower eating rate may reduce overall food intake. 
  • Use a food diary, or an app such as MyFitnessPal, to keep track of what you are eating and drinking. This can help show whether you are successfully creating a calorie deficit.  

As well as how much you eat, the kind of foods you eat are also important when it comes to improving your body composition. While we should aim to eat a balanced and varied diet including all the food groups, one of the most important in this context is protein. 


A top down view of a variety of different types of protein, including meat, eggs, nuts, and dairyCredit: Shutterstock/Tatiana Bralnina

If we want to improve our body composition, then as we said before, for most people this means building muscle as well as reducing body fat. And to build muscle, we need protein. 

Protein is a key building block in muscle growth (as well as many other things) and is essential for repairing muscles after exercise. For anyone who wants to reduce their body fat but keep (or even gain) muscle mass, it’s important to eat enough protein.  

Dr Patel explains: 

Protein plays a crucial role in building and maintaining muscle mass. When you consume protein, it provides the necessary amino acids for the creation of new muscle proteins to repair and build muscle fibres.  

“Protein is essential for repairing and recovering damaged muscle tissue. During exercise, especially resistance training, muscles experience microscopic damage. Adequate protein intake supports the repair of these damaged muscle fibres, allowing them to become stronger and adapt to future exercise.” 

Added to this is the fact that as we age, we lose muscle mass through a process called sarcopenia. While eating protein won’t turn back time, it can help to slow this process down. By holding onto as much muscle as possible, we give ourselves the best chance of improving our body composition. 

Sarcopenia is an age-related, involuntary loss of muscle mass. According to some studies, as much of 50% of our muscle mass may be lost by the time we reach our eighth decade of life. 

Dr Patel adds: “In the absence of adequate protein intake, the body may break down muscle tissue to obtain the necessary amino acids for other bodily functions. Consuming enough protein helps preserve muscle mass, especially during periods of calorie restriction or weight loss.”  

There’s another benefit of eating plenty of protein: it can help us feel fuller by reducing ghrelin, a hormone that makes us feel hungry. In turn, this can help us reduce our overall calorie intake. This is obviously helpful if we’re trying to lose weight.  

As a combination, holding on to healthy muscle while trying to lose weight is an important factor in improving your body composition.  


Regular movement is important

When it comes to changing your body composition, diet is only one part of the puzzle. Exercise is another element that can have a major influence. Of course, exercise of any kind can be good for us. But there are some types of exercise that can be especially beneficial for improving your muscle mass.  

Strength training

An older man and woman in the woods doing weight training with light dumbbellsCredit: Credit: Shutterstock/LightField Studios

Personal trainer, dance instructor and BioSure ambassador Francesca Bradford, tells us: “Weight training is the most effective way to get your body into the type of shape you most desire and, if performed correctly, can also improve your cardiovascular health.” 

There are many benefits to strength training, including improved strength, endurance and stronger bones. “Weight training also decreases your risk of injury, as it increases bone density and stabilises your joints as the connective tissues get stronger. This is extremely important as we get older. If you have strong bones, muscles and joints, this will protect us from things like slips and falls,” Bradford says. 

But in terms of our body composition, the key benefits of strength training are increased testosterone production, and greater metabolic rate. 

Testosterone production helps by increasing muscle growth. And because muscle is considered ‘metabolically active’ (basically, it burns more calories than fat does) it can also help to burn fat. In effect, as you build muscle, this could also help to reduce your body fat at the same time. 


Two women exercising outdoors with hula hoopsCredit: Credit: Shutterstock/

Bradford says: “HIIT stands for High-Intensity Interval Training. HIIT training really improves cardiovascular health and has been proven to continue to burn calories for a number of hours after your workout is complete. And high intensity does not necessarily mean high impact!

A lot of people think of hundreds of burpees and jumping non-stop when it comes to HIIT, but this doesn’t have to be the case. High intensity is any exercise that elevates your heart rate.” 

Alongside strength training, HIIT workouts have been shown to have benefits in maintaining muscle mass. 

And without repeating ourselves too much, if we want improved body composition, then holding onto as much muscle mass as we can is a valuable part of the equation.  


As important as exercise is all the energy we use outside of exercise. This is known as non-exercise activity thermogenesis (NEAT) and includes things like walking, standing or even fidgeting.

Studies suggest that NEAT-type activities may have a significant beneficial effect on weight management. Put simply: moving more is good for us, even if we aren’t engaging in formal exercise activities. 

Exercises that can improve body composition:

  • Strength training
  • HIIT
  • Walking
  • Yoga
  • Pilates
  • Daily activities, such as gardening, housework and climbing the stairs 

And finally: according to Bradford, “The science also says that as your muscles recover from both weight and cardio training, it can promote longer and better sleep quality, so if you are struggling with getting enough restful sleep, it’s another reason to give regular exercising a go.” And as we’ll see, good sleep is also an important factor in improving your body composition. 


Good sleep can make a big difference

A bird's eye view of a couple asleep in bedCredit: Shutterstock/

It probably makes sense that diet and exercise are important for your body composition. But did you realise that getting a good night’s sleep is critical for changing your body composition? Sleep medicine physician Dr Joshua Roland tells us:  

Sleep has a role in regulating every organ system in the body and is essential for our optimal biological functioning. Muscles need sleep to repair and grow. Testosterone and growth hormone (GH), two hormones needed for muscle growth, are both released during sleep. Other processes regulating metabolism and glucose level are controlled in part by sleep as well.” 

Poor sleep has been linked with the risk of weight gain and obesity. Studies suggest that poor sleep can interfere with the hormones leptin and ghrelin, which are important for controlling appetite. And we’ve probably all found ourselves craving sweet treats and other calorie-dense foods when we’re feeling particularly tired.  

Leptin and Ghrelin explained

Leptin is a hormone that is believed to regulate appetite and makes us feel full. It may also influence other processes, such as metabolism and immune function. 

Ghrelin is known as the ‘hunger hormone’ as it signals to your brain when it’s time to eat. More ghrelin in your body is linked with eating more. 

If you’re struggling to sleep, guidance is available from the NHS. We’ve also got some expert sleep tips to help improve your sleep. 

It may be surprising, but sleep can have a profound influence on improved body composition. Making sure you have healthy sleeping habits and are getting enough good quality sleep, can help to regulate your hormones. In turn, this can help you reach your body composition goals. 


Keep calm and carry on

A man sitting at a computer screen with his fingers on his temples. He looks worriedCredit: Shutterstock/ – Yuri A

Stress can also be a factor influencing your body composition. Some studies have shown a link between cortisol levels and abdominal obesity. Cortisol is released when we are stressed and the suggestion is that cortisol can contribute to us storing more fat.  

There are plenty of other negative impacts of stress, including high blood pressure, mental health problems and poor sleep, to highlight a few examples. And then there’s also the propensity for us to indulge in less healthy coping mechanisms, such as increased drinking, smoking or eating too much. All of which can make it harder to change our body composition for the better. 

In theory, reducing our stress levels may then reduce the amount of cortisol in our systems, which, in turn, may make it easier to reduce our body fat and build muscle. The NHS offers some advice on how to cope with stress.  

How to measure your body composition

Some methods are easier than others

Of course, making all these changes won’t mean that you see an overnight transformation. Consistent effort over a period will lead to the changes we are talking about. But how can we measure our body composition? 

There are multiple ways of doing this. The most accurate are the gold standard methods such as dual x-ray absorptiometry (DXA) scan and hydrostatic weighing (also known as densitometry). But these are typically quite expensive to arrange and need to be done in a controlled setting. 

At home, you can use skinfold callipers (but this requires a second pair of hands to help with the measurements) or smart scales. While there are some question marks around how accurate smart scales are, if you use them consistently, then the trends they show will likely be a true reflection of what’s happening to your body composition.  

Beyond this, take note of things such as how your clothes fit, how you feel, and whether you notice yourself getting fitter, faster and stronger. Even if the number on the scales stays the same, it doesn’t mean that your body composition isn’t changing. 

Improving your body composition involves a range of factors that are often closely interlinked. By focusing on the areas we highlighted above, you may well start to see greater improvements in your overall health and fitness, than by concentrating on weight alone. 

Steven Shaw

Written by Steven Shaw he/him


Steven Shaw has been a freelance writer for a variety of outlets, most notably TechRadar. His degree in Medieval History prepared him less adequately for his career than you might expect, but the years spent working in technology focused retail were much more helpful.

Outside of work, Steven is passionate about health and fitness, and particularly enjoys high-intensity interval training, weight training, and increasingly, spending time recovering. Steven loves reading, films and a wide variety of sports. A particular highlight was watching Viv Richards and Sachin Tendulkar batting together in an exhibition match.

He wishes he could travel more. He can also tell you a lot about the Anglo-Saxons, Vikings, and Carolingians. Most of his non-work time is spent with his young children, who are the living embodiment of high-intensity training.