Body Composition

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BIA | Bioelectrical Impedance Analysis

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What is BIA?

What does the data mean?

Normative information

The technology

What is BIA?

Bioelectrical Impedance Analysis (BIA)

This method has become increasingly popular due to ease of access, cost-effectiveness and portability.

During measurement, a small electronic current will be passed through the body at different frequencies to assess body composition based on the conductivity of fat mass (FM) and fat free mass (FFM).

FFM will contain water and electrolytes, therefore making it a good electrical conductor. FM on the other hand is the opposite and will not conduct the current effectively.

BIA machines with higher frequencies provide more accurate results due to the ability of the higher frequencies to pass through cell walls.

Most BIA machines will be able to identify body fat percentage and mass, muscle mass, bone mass and total body water amongst other results.

As BIA uses an electrical current, individuals with pacemakers or any other mechanical implants should not use this method and those who are pregnant or have allergies to metals should consult their doctor before use.

Preparation for a BIA assessment is essential for reliable and valid results.  See the following GPTQA video for advice:

What does the data mean?

Different BIA machines collect varying information however the following is indicative of the systems used by Global Wellness Tracking

Total mass (total body weight)

The total mass is often referred to as total body weight and the most common measure used.  The total mass is then divided into the different mass categories.

Example:

  • Total mass | 86.5 kg (100%)
  • Fat mass | 18.4 kg (21.3%)
  • Fat free mass | 68.1 kg (78.7%)
    • Muscle mass | 64.7 kg
    • Bone mass | 3.4 kg

Body fat mass (FM)

Body fat mass is the actual weight of fat in your body. Body fat percentage (%) is the proportion of fat to the total body weight.

Body fat is essential for maintaining body temperature, cushioning joints and protecting internal organs.

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 composition monitor.

Fat free mass (FFM)

Total body weight excluding body fat mass.

Fat Free Mass includes everything from skin, bones, ligaments and tendons, to organs and water content. A high level of fat free mass generally implies a lean and healthy body frame.

Body fat percentage

Body fat consists of essential body fat and storage fat. Essential body fat is present in the nerve tissues, bone marrow, and organs (all membranes), and we cannot lose this fat without compromising physiological function.

Storage fat, on the other hand, represents an energy reserve that accumulates when excess energy is ingested and decreases when more energy is expended than consumed.

Essential body fat is approximately 3% of body mass for men and 12% of body mass for women. Women are believed to have more essential body fat than men because of childbearing and hormonal functions.

In general, the total body fat percentage (essential plus storage fat) is between 12% and 15% for young men and between 25% and 28% for young women.

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.

Bone (skeletal) 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.

Total body water (TBW)

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.

Intracellular water (ICW)

The fluid present inside cells.

Two thirds of the Total Body Water (TBW) in an average healthy person will consist of Intra Cellular Water.

Extracellular water (ECW)

Shows the relationship between Extra Cellular Water as a proportion of Total Body Water and is a general indicator of hydration and health

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.

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.

Visceral fat rating

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 composition monitor helps you keep track of potential problems and test the effectiveness of your diet or training.

Body mass index (BMI)

Body mass index, or BMI, is one way to assess whether your weight is in the healthy range. The BMI combines a person’s height and weight to form a measure that can help predict their risk of developing disease.

Health researchers have found BMI to be a good indicator for the health and lifespan of adults – not necessarily for an individual, but for a group of people who have the same BMI. For example, researchers have shown that a group of people with BMIs of 30, is more likely to have serious illness and die younger, on average, than a group of people with BMIs of 20.

It is important to note that the fundamental calculation of BMI assumes changes in height and weight therefore once and individual has reached their peak growth, the primary change is in weight only.

Normative information

Normal ranges based on health and medical resources globally.  Please refer to your health professional for individual needs and levels.

Body fat percentage

Average population

Males:

  • Up to 30 years | 9 – 15%
  • 30 – 50 years | 11 – 17%
  • 50+ years | 12 – 19%

Females:

  • Up to 30 years | 14 – 21%
  • 30 – 50 years | 15 – 23%
  • 50+ years | 16 – 25%
  •  

Percentages by classification – Males

  • 20 – 39 years
    • Underfat | <7%
    • Healthy | 7 – 20%
    • Overfat | 20 – 25%
    • Obese | >25%
  • 40 – 59 years
    • Underfat | <10%
    • Healthy | 10 – 22%
    • Overfat | 22 – 28.5%
    • Obese | >28.5%
  • 60 – 79 years
    • Underfat | <12%
    • Healthy | 12 – 25%
    • Overfat | 25 – 30%
    • Obese | >30%

Percentages by classification – Females

  • 20 – 39 years
    • Underfat | <21%
    • Healthy | 21 – 34%
    • Overfat | 34 – 39.5%
    • Obese | >39.5%
  • 40 – 59 years
    • Underfat | <23%
    • Healthy | 23 – 34%
    • Overfat | 34 – 40%
    • Obese | >40%
  • 60 – 79 years
    • Underfat | <24%
    • Healthy | 24 – 36%
    • Overfat | 36 – 41.5%
    • Obese | >41.5%

Body mass index (BMI)

Calculation

Body mass index = weight (kg) / height (m)2

Normal ranges and classification

  • Underweight | <18.5
  • Healthy weight range | 18.5 – 24.9
  • Overweight | 25 – 29.9
  • Obese | >30

Basal metabolic rate (BMR)

Energy expenditure is continuous, but the rate varies throughout the day. The rate of energy expenditure is usually lowest in the early morning.

Average BMR

  • Male | 7,100 kJ per day
  • Female | 5,900 kJ per day

Visceral fat

Ranges

  • Healthy | 1 – 12
  • Excessive | 12 – 59

Bone (skeletal) mass

Ranges

Males:

  • Body weight | <65 kg = 2.65 kg healthy bone mass weight
  • Body weight | 65 – 95 kg = 3.29 kg healthy bone mass weight
  • Body weight | >95 kg = 3.69 kg healthy bone mass weight

Females:

  • Body weight | <50 kg = 1.95 kg healthy bone mass weight
  • Body weight | 50 – 75 kg = 2.40 kg healthy bone mass weight
  • Body weight | >75 kg = 2.95 kg healthy bone mass weight

Total body water

The average TBW% ranges for a healthy person are:

  • Female 45 to 60%
  • Male 50 to 65%.

 

The technology
Tanita MC980 body composition analyser

The MC-980MA PLUS is the ultimate tool in providing comprehensive information for personalised health and fitness consultations.

Incorporating the latest multi-frequency BIA technology with the flexibility of an upgraded Microsoft® Windows® 8 OS and expanded memory function, this monitor provides fast, convenient and accurate information.

The new Sarcopenia Assessment feature allows the identification, prevention and monitoring of elderly clients.

The MC-980MA PLUS provides a full clinically accurate body composition analysis in less than 30 seconds and has an easy-to-follow colour interactive touch screen display. The in-built software runs in 14 languages and detailed consultation sheet shows the client’s full results, provides a firm basis for a full consultation, personalised goal setting and progress report. The USB ports allow simple data input or output as well as accessories to be connected including printers, bar code scanners and data capture devices.

Measurements & specification:

  • Weight
  • Body fat %
  • Total body water 5
  • Muscle mass
  • Physique rating
  • Bone mineral mass
  • Basal metabolic rate
  • Metabolic age
  • Body mass index
  • Visceral fat
  • 5 segmental fat readings
  • 5 segmental muscle readings
  • Weighing capacity | 300kg
  • 4 compartment analysis
  • 6 frequency analysis