Help & Guides

If you can measure it, you can manage it!.

Body composition

The definition of body composition is 'the percentages of bone, fat, water and muscle in human bodies'. All these factors can be measured. 

This page explains what body composition is, how knowing your body composition can help you and how you can measure it. Do you want to know what measurements there are and what they entail? Then check out our Understanding your Measurements page.

Body composition is a word that’s commonly used by professionals who work in medicine, fitness and health. This term is frequently used, because it’s an important health indicator.

If you have a good understanding of your own body composition, you can effectively improve your wellbeing.

What is body composition

Body composition is a method to gain insight into your physical health. It gives a broad range of information about the state of your body. This gives you valuable indight into how you can set goals for risk prevention matters and/or keep your body in balance. In that sense it’s similar to using the body mass index (BMI) as a health indicator. However, BMI is notoriously unreliable on the individual level.

Body composition on the other hand, includes measurements such as fat, muscle, water and bones. Taking all these components into account makes this approach much more accurate. 

Why it is useful

A body builder and a couch potato may be the same age, height and weight. Their BMI’s wouldn’t show any differences. However, the weight of one mainly consists of muscle and the other’s of fat. Therefore, they have much different

  • exercise needs;
  • nutritional needs;
  • health risks; and
  • fitness goals.

 If they knew their body composition, this would have been very clear. The couch potato can start doing sports while measuring body fat percentage and muscle growth. A scale might show their weight to stay the same (very demotivating), while they are actually gaining muscle and losing fat. Knowing your body composition makes actual progress crystal clear.

The body builder can use a segmental body composition monitor to measure the status of different parts of their bodies. This allows them to spot muscle imbalances or identify areas that require extra training.

Body composition analysis

The outcome of the body composition analysis gives insights about your physical wellness. By doing an analysis you get a thorough evaluation of the components of your body composition. Whether these components are in a healthy range depends on many factors. It differs within gender, age, weight to just name a few.

Also note different sports have different body composition requirements: a marathon runner will have way less muscle mass than a body builder. The components of body composition can be divided within two groups:

  • Lean body mass (muscles, body water and bones)
  • Fat body mass (the percentage of body fat)

The reasons why you need to analyse your body composition:

  • It will motivate you to achieve your goals
  • It will give you an estimation of how healthy you are
  • It will help you to discover your health risks and prevent them from developing
  • It will help you to set the right goals to keep yourself in balance and get you in the right shape to make yourself as healthy is you want to be
  • It will help you to make the right estimation of how much and which nutrition’s you need.
  • It helps you to discover which exercises are effective for achieving your goals

Body composition monitors

So, how do you gain insight in your body composition? For that you can use a body composition monitor. Tanita’s monitors are known for their accuracy and therefore used in hospitals and gyms. They measure the following:

Body Fat Percentage and Body Fat Mass

Body Fat Percentage is the proportion of fat to the total body weight. Body Fat Mass is the actual weight of fat in your body.

Body fat is essential for maintaining body temperature, cushioning joints and protecting internal organs. Body fat scales can help you keep track of your body fat.

The energy, or calories, our body needs comes from what we eat and drink. Energy is burned through physical activity and general bodily functions. If you consume the same number of calories as you burn, all the calories are converted into energy. But if you consume more than you burn, excess calories are stored in fat cells. If this stored fat is not converted into energy later, it creates excess body fat.

Although you need healthy body fat, too much fat can damage your long-term health. Reducing excess levels of body fat has been shown to directly reduce the risk of certain conditions such as high blood pressure, heart disease, type 2 diabetes and certain cancers.

Too little body fat may lead to osteoporosis in later years, irregular periods in women and possible infertility.

It is important to keep track of your body fat with a body fat scale. Then you can check your body fat results against the Tanita healthy body fat ranges. These measurements are available for everyone from age five to 99 years.

For children’s health body fat ranges click here:
For adult's healthy body fat ranges click here:

Visceral Fat

Visceral fat is located deep in the core abdominal area, surrounding and protecting the vital organs.

Even if your weight and body fat remains constant, as you get older the distribution of fat changes and is more likely to shift to the abdominal area. Ensuring you have a healthy level of visceral fat directly reduces the risk of certain diseases such as heart disease, high blood pressure and may delay the onset of type 2 diabetes.

Measuring your visceral fat with a body fat scale helps you keep track of potential problems and test the effectiveness of your diet or training.

Muscle Mass

The predicted weight of muscle in your body.

Muscle mass includes the skeletal muscles, smooth muscles such as cardiac and digestive muscles and the water contained in these muscles. Muscles act as an engine in consuming energy.

As your muscle mass increases, the rate at which you burn energy (calories) increases which accelerates your basal metabolic rate (BMR) and helps you reduce excess body fat levels and lose weight in a healthy way.
If you are exercising hard your muscle mass will increase and may increase your total body weight too. That’s why it’s important to monitor your measurements regularly to see the impact of your training programme on your muscle mass.

Total Body Water

Total Body Water is the total amount of fluid in the body expressed as a percentage of total weight.

Body water is an essential part of staying healthy. Over half the body consists of water. It regulates body temperature and helps eliminate waste. You lose water continuously through urine, sweat and breathing, so it’s important to keep replacing it.

The amount of fluid needed every day varies from person to person and is affected by climatic conditions and how much physical activity you undertake. Being well hydrated helps concentration levels, sports performance and general wellbeing.

Experts recommend that you should drink at least two litres of fluid each day, preferably water or other low calorie drinks. If you are training, it’s important to increase your fluid intake to ensure peak performance at all times.

Read all about body water.

The average TBW% ranges for a healthy person are:
Female 45 to 60%
Male 50 to 65%

Bone Mass

The predicted weight of bone mineral in your body.

While your bone mass is unlikely to undergo noticeable changes in the short term, it’s important to maintain healthy bones by having a balanced diet rich in calcium and by doing plenty of weight-bearing exercise.
You should track your bone mass over time and look for any long term changes.

Physique Rating

Assesses muscle and body fat levels and rates the result as one of nine body types.

As your activity level changes, the balance of body fat and muscle mass will gradually change, which in affects your overall physique. The physique rating which our Body Composition Monitors provide give you insight in what body type you currently have.

Basal Metabolic Rate (BMR)

The daily minimum level of energy or calories your body requires when at rest (including sleeping) in order to function effectively.

Increasing muscle mass will speed up your basal metabolic rate (BMR). A person with a high BMR burns more calories at rest than a person with a low BMR.

About 70% of calories consumed every day are used for your basal metabolism. Increasing your muscle mass helps raise your BMR, which increases the number of calories you burn and helps to decrease body fat levels.

Your BMR measurement can be used as a minimum baseline for a diet programme. Additional calories can be included depending on your activity level. The more active you are the more calories you burn and the more muscle you build, so you need to ensure you consume enough calories to keep your body fit and healthy.

As people age their metabolic rate changes. Basal metabolism rises as a child matures and peaks at around 16 or 17, after which point it typically starts to decrease. A slow BMR will make it harder to lose body fat and overall weight.

Metabolic Age

Compares your BMR to an average for your age group.

This is calculated by comparing your basal metabolic rate (BMR) to the BMR average of your chronological age group. If your metabolic age is higher than your actual age, it’s an indication that you need to improve your metabolic rate. Increased exercise will build healthy muscle tissue, which in turn will improve your metabolic age. Stay on track by monitoring regularly.

Body Mass Index

A standardised ratio of weight to height, used as a general indicator of health.

Your BMI can be calculated by dividing your weight (in kilograms) by the square of your height (in meters).

BMI is a good general indicator for population studies but has serious limitation when assessing on an individual level. 

Muscle quality

indicates the quality / state of the muscle which changes according to factors such as age and fitness.

The muscle quality of young people or those who exercise regularly are normally in a good state. The state of muscles deteriorates in elderly people and those who do not get enough exercise. Innerscan Dual Body Composition Frequency analyser RD-953, uses 2 different frequencies to measure bioelectrical impedance and these results are used to evaluate the muscle state using the muscle quality

DCI – Daily calory intake

An estimate of how many calories you can consume within the next 24 hours to maintain your current weight.

Daily Calorie Intake (DCI) is the sum of calories for basal metabolism (BMR), daily activity metabolism (activities including daily household chores), and diet-induced thermogenesis (energy used in connection with digestion, absorption, metabolism, and other eating activities). Use this as a guideline in your daily meal planning. Consuming fewer calories that your predicted DCI value will help you lose weight, be sure to maintain a good physical activity so you do not lose muscle mass.

Muscle quality score

The muscle mass is assessed for persons 18 years and older.

Muscle mass is judged by calculating the amount of muscle mass against the persons height and then the amount is classified. The RD-953 displays the muscle mass judgement as a muscle score. The larger the number, the more muscle mass a person has.


Segmental Muscle Mass

Muscle mass rating for five body parts: the core abdominal area and arm and leg.

Monitoring the segmental muscle mass of each of your arms and legs and core abdominal area will help you see and understand the impact of your training programme over time. You can also use this information to correct muscle imbalances and avoid injury.

Segmental Body Fat Percentages

Body fat percentages for five body segments: the core abdominal area and each arm and leg.

Monitoring the segmental body fat percentages of each of your arms and legs and core abdominal area will help you see and understand the impact of your training programme over time.

People are also interested in:

Muscle Mass
Start building your muscle mass today!
Visceral Fat
Keep an close eye on your fat percentage.
A rough indication
What type of body do your have?
Are you as strong as you look?
Body Water
Are you drinking enough water?

Do you know your BMR?
Bone mass
Are you solidly built?
Are you at a healthy weight?

Take full control of your body.

Monitor your body with the RD-545, a medical grade scale that offers 20 types of body composition monitoring and even lets you mease per segment of your body.