Body composition scales: Understanding your measurements

Body composition scales provide a complete picture of body health - useful in hospitals for medical diagnosis and in gyms to help with achieving fitness goals.

The Marsden body composition scales range was updated last month, and now the MBF-6000 and MBF-6010 provide a picture of body health in even greater detail.

To ensure you get the most out of your body composition scale, this blog post will help you understand the measurements the scales provide - and if you need any more help, get in touch with our team.

What is a body composition scale?

A body composition scale is a type of weighing scale which provides the user with a calculation of their body health. Body composition measurements include body fat, muscle mass and and metabolic rate, and over time the user can see, in detail, the results of their weight loss or fitness programme.

As well as gyms, sports clubs and slimming clubs, hospitals use body composition scales as they help provide a true assessment of patient health.

Marsden body composition scales use biometric impedance to calculate the readings. This means a safe and very small electrical current flows through the body from the base of the scale. It works because electrical current flows through matter , such as water, fat and muscle, at different speeds - allowing the scale to calculate the volume of each element within the body based on the speed of the electrical current.

In times of rising obesity, a knowledge of body composition can help patients or gym members to stay in shape.

How accurate are body composition scales?

Marsden body composition scales are Class III Approved which means that legally they can be used in hospitals for monitoring, diagnosis and treatment.

The NHS use DEXA scanners - a special type of X-ray specially designed to identify low bone mineral density - and because these carry out a full body scan, they are about as accurate as you can get for measuring precisely the composition of a body. Thus, DEXA scanners are seen as the ‘gold standard’ for body composition and the standard that Marsden judges body composition scales by.

Marsden body composition scales are closer to DEXA than any other body composition scale tested. In a BBC One Show test it noted inaccuracies in bathroom scales of up to 30% - yet the Marsden MBF scales are within 3% of DEXA. The closest competitor tested by Marsden during development of the MBF-6000 and MBF-6010 was within 7% of DEXA.

What do body composition scale readings mean?

The most common readings on a body composition scale are BMI, Body Fat Percentage, Total Body Water, Basal Metabolic Rate, Fat Mass and Fat Free Mass. At Marsden, we’ve recently updated our body composition scales to deliver a further nine readings - Bone Mineral content, Muscle Mass, Protein Mass, Extracellular Water, Intracellular Water, Skeletal Muscle, Visceral Fat Area level and Health Score.

Body Mass Index (BMI)

BMI is the most common way of determining overall body health and whether a person is underweight or overweight.

To calculate BMI simply divide a person’s weight in kilograms by square metres in height. BMI can be calculated on many weighing scales. It is a non-invasive way of assessing body weight - with links drawn between BMI and illness. BMI scales are a popular choice for many users to better understand their body health; however, BMI does not provide an indication of the distribution of body fat.

For more information on healthy BMI, download this helpful BMI infographic poster.

Body Fat Percentage

Body Fat Percentage gives a good indication of body health, but interpreted by itself could give a slightly misleading picture.

The Royal College of Nursing says the healthy target for body fat percentage changes with age. For men aged 20-39, for example, target body fat percentage is 8-20%; after 60 years of age this increases to up to 25%.

Body fat percentage is the proportion of fat mass compared to everything else (bones, muscles and water) and is displayed as a percentage.

Total Body Water (TBW)

The Total Body Water measurement shows how hydrated the body is. Water is used in the body for transporting waste, helping organs to function, regulating body temperature and digestion.

The amount of fluid consumption required varies from person to person, and is influenced by climate and the amount of physical activity undertaken. Experts recommend an individual’s consumption should be at least two litres of fluid per day.

An average Total Body Water reading for men is 55-60%; for women it is 50-55%.

Basal Metabolic Rate (BMR)

Basal Metabolic Rate is the amount of calories your body needs to function. It is based on the number of calories the body would need if resting for 24 hours. This allows you to calculate an accurate calorie intake target for your body - far more accurate than a generic calculation which might be found online - enabling you to create a diet programme.

A person with a high BMR burns more calories than a person with a low rate. Around 70% of calories consumed every day are used for your basal metabolism. It fits hand in hand with muscle mass, as the greater the muscle mass, the higher the BMR and the more calories are burned.

Fat Mass and Fat Free Mass (FM/FFM)

Fat Mass is the total mass of the fat in the body and Fat Free Mass is everything else: including bones, muscle and water.

Some body fat is classified ‘essential fat’ - which the body needs to function, and keep organs warm. Therefore a very low Fat Mass reading can be dangerous.

Calories or energy in the body come from what we eat and drink. Energy is burned from physical activity, but if you consume more than you burn excess calories are stored in fat cells, culminating in excess body fat. Too much body fat can damage long-term health.

You can read more about these readings in this white paper.

Visceral Fat Area level (VFA)

Visceral Fat is the fat which protects vital organs. Ensuring you have a healthy level of visceral fat directly reduces the risk of diseases such as heart disease and high blood pressure.

VFA is used to determine the risk of diabetes, alongside BMI. VFA is shown as a level out of 50, with a score of 41-50 indicating an extremely high risk.

Muscle Mass (MM)

This consists of skeletal muscles, smooth muscles and the water which is contained within them. As muscle mass increases, the rate at which energy is burned increases, accelerating the basal metabolic rate. An increase in muscle mass may increase total body weight, and muscle weighs more than fat. Therefore, it is important to monitor each aspect of the body separately using body composition measurements.

Bone Mineral content (BM)

This tracks the amount of bone mineral found in the body. A higher bone density and strength is indicated by a higher bone mineral content.

Calcium is the largest contributor of bone mineral content. Find out more here.

Protein Mass

Protein Mass tracks the amount of protein in the body. A lack of protein can be linked to an increase in body fats. There is a link between protein mass and muscle mass. As you get older you need more protein due to anabolic resistance, which lowers the body’s ability to break down and synthesize protein.

Extracellular Water (ECW)

Water found outside of cells is called Extracellular water - which helps tissue to function well. Nutrients are served to membrane-bound cells via extracellular water, such as sodium, potassium, calcium, chlorides and bicarbonates. An increase in extracellular water can cause excess weight and swelling in your limbs. Imbalances may cause symptoms such as decreased mental alertness, nausea and dizziness or result in high blood pressure.. Typically, roughly one third of your body is extracellular water.

Intracellular Water (ICW)

Water that is located inside your cells is intracellular water - in healthy people it comprises two thirds of the water inside your body. This type of water plays an important role in allowing molecules to be transported to different organelles inside the cell.

Having an increased ICW can signal a positive change in your body composition. When muscle cells become larger, they require more ICW in order to power their cellular functions. Increased ICW contributing to an increased lean body mass can lead to an improved BMR, increased strength and a better immune system.

Skeletal Muscle (SM)

Skeletal Muscle is one of three major muscle types (alongside cardiac and smooth muscle). It is the most common of the three. These types of muscles are attached to bones by tendons and produce all the movements of body parts in relation to each other.

Metabolic Age (AGEM)

This is worked out by comparing the Basal Metabolic Rate to the average BMR of your age group. If the metabolic age is higher than your actual age, it is a sign that you need to improve your metabolic rate.

Health score

Health score provides an overall score for your body, taking into account height, age, weight and gender information. It is calculated out of 100; the higher the score the better.

Marsden body composition scales

MBF-6000: This scale provides a comprehensive body health assessment in a portable scale. It has a 300kg capacity and graduations to 100g. They are widely used in hospitals and gyms, whilst the portability aspect means they are suited for use by mobile physicians, physiotherapists, nurses and personal trainers. They cover all the features listed above, and are supplied with a printer.

MBF-6010: This body composition scale is widely used in hospitals, gyms and sports clubs. It differentiates from the MBF-6000 because it is fitted with a column and makes for a more permanent solution.

Advanced body composition readings

Body composition scales tell you a lot about your body and your fitness. But you can take that analysis one step further with an Advanced Body Composition Analyser, like the MA601. Monitor rehabilitation progress, detect hidden obesity risks and precisely evaluate sarcopenia, with a comprehensive print-out of your results. Find out more here.

To find out more about Marsden body composition scales, or if you have any questions about body composition measurements, email our team at

Outside of the UK? You can order Marsden scales through one of our international dealers - or direct from us, over the phone. Speak to our team on +44 (0) 1709 364296 to find out more.

You can download a useful ‘Body Composition Scales: What’s Healthy?’ poster from 2016 here.

14 thoughts on “Body composition scales: Understanding your measurements”

  • Justin youck
    Justin youck 14/10/2020 at 3:33 am

    I weigh 121.3lbs at 5’4”. I have a 20.7 bmi, 7%bfp 48.7% muscle rate, 66.6% body water, 5.3 lbs of bone mass, 1414.07 bmr, 20.1% protein rate, 2.0 vfi, 9.7% subcu fat, 8.6 lbs of fat mass, 59lbs of muscle mass, and 24.5 lbs of protein mass. Do I have anything to worry about except for a low fat mass?

    • Marsden

      Thank you for your comment. We can advise on how to get the most out of body composition scales/BIA scales, however for accurate feedback on body health we recommend consulting with a fully qualified fitness professional.

  • Pat

    At 97.6 lbs and 64 years old is 14.9% protein good? And also my skeletal muscle rate is 38.8%. Is that also good

    • Marsden

      Thank you for your comment. Without further information, for example height, BMI and ethnicity, we would not be able to give you a definitive answer to your question. It is always recommended that you refer to accepted standards as promoted by recognised bodies, such as the American College of Sports Medicine, or the NHS. Good segmental scales like the MA601 can also compare your readings to what is regarded as ‘healthy’, based on your age, weight, height, sex and so on.

  • Marion Squires
    Marion Squires 02/10/2020 at 6:17 pm

    My protein went from 25% to 7% is that good or do I need to eat more protein

    • Marsden

      Hello Marion,

      Protein should account for around 15% of your body composition.
      The drop from 25% to 7% is quite concerning and it may be worth contacting your GP for a check up.

      Kind Regards,

  • Reem

    My scale says I have a total body proteins of 13.3 percent and my muscle mass is 43.7 percent what is the difference

    • Marsden

      Hello Reem,

      Protein is the building block of your muscles. By eating protein, you can maintain and grow your muscle mass.

      Kind Regards,

  • Trish

    Great document, explains loads I didn't understand, my scale are showing 6 extreme over nutrition, but my green, red and yellow foods are all well balanced. Can anyone help please

    • Marsden

      Hello Trish,

      I'm sorry to hear that! Would you be able to let me know which scale you're using?
      Then I can try my best to help.

      Kind Regards,

  • Savanna Pollard
    Savanna Pollard 11/09/2020 at 4:05 pm

    My muscle mass is decreasing as well as my weight and body fat, but my skeletal muscle is increasing so is that good enough or should I be concerned I’m losing muscle mass?

    • Marsden

      Hello Savanna,

      Thank you for getting in touch. The good news is that your skeletal muscle is increasing - that's a great result and shows your training is working.
      In terms of your muscle mass decreasing, this could just be a result of age, as muscle mass will begin to decrease as you get older. Or it may be attributed to a lack of sleep, preventing your body from rebuilding.

      Kind Regards,

  • Lisa Van Lanen
    Lisa Van Lanen 06/09/2020 at 2:57 pm

    My body composition scale says I have 18.6 of protein in my body is that good or bad?

    • Marsden

      Hello Lisa,

      It typically depends on your age and weight but 18.6 is a good result.

      Kind Regards,

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