Anthropometry Information
Why does it matter what I measure?
How do I improve my measurements?
Obesity is a major risk factor implicated in heart and circulatory disease. It also affects your body’s endocrine system (the system responsible for the release of hormones) and can lead to metabolic diseases such as diabetes.
There are many other negative effects of obesity such as the stress on joints that can lead to osteoarthritis, the compression of lung volume that can affect breathing efficiency and the constriction of the airways when lying down that can cause sleep apnoea to name but a few.
If you have had a BlueSkies Health MOT and want to improve your BMI, Body Fat Percentage or Waist Circumference, this information will help you to do that.
NB The information on this page should not supersede that given by your GP or medical professional.
What is anthropometry?
Anthropometry is the term given to the measurement of the human body – it includes height, weight & circumference measurements as well as body composition analysis.
These measurements can be used to calculate other indices such as Body Mass Index (BMI) and Waist to Hip Ratio (WHR) which allow an individual to be compared to population norms. Another important reason for measuring anthropometry is to monitor change in an individual over time.
Why does it matter what I measure?
Human bodies are all different and it’s unrealistic to expect everyone to fit neatly into any pre-determined category. However, there are some limits within which the body operates more efficiently and is at a lower risk of certain diseases.
The following commonly taken measurements of the human body are explained below along with the reason why each may be relevant to you:
For the latest research findings concerning weight, click here.
Height
This is largely determined by your genes although posture, injury, dehydration, age and conditions such as osteoporosis will all impact on height.
Weight
This is a measure of your total body mass and will be determined in part by your genes, body build and bone mass density. However, weight changes during life are typically due to changes in either fat tissue or muscle tissue within the body. Weight alone tells us very little about a person’s health.
Body Mass Index (BMI)
BMI is a index that is used to assess how healthy your weight is for your height - it is a product of your weight divided by your height squared e.g.
BMI = Weight (kg) / Height (m2 / m sq)
Your BMI can be compared with normative data to indicate how your weight compares to the population averages for people of your height. However, there are limitations to the usefulness of BMI because it does not take account of the composition of the body tissues that make up a person’s weight.
For 2 people of the same weight, one may have a high proportion of muscle tissue, the other a high proportion of fat – the two will not have the same health risks despite having the same BMI.
That said, BMI is the standard indicator used to identify obesity by the medical profession and insurance companies and it is reliable as an indicator of health for the general (non-athletic) population.
Body Mass Index can be calculated in the following way, once you know your height (in metres) and your weight (in kilograms):
- Work out your height (m sq) = height (m) x height (m)
- Work out your BMI = weight (kg) / height (m sq)
For example, a person of 1.65m height who weights 72kg would work out their BMI by:
- Height (m sq) = 1.65 x 1.65 = 2.7225
- BMI = 72 / 2.7225
- BMI = 26.4
Alternatively, to quickly and easily calculate BMI using metric or imperial measurements you can use a BMI calculator. BlueSkies BMI calculator & tape measure allows you to quickly work out your BMI and has a colour-coded tape measure that identifies how 'healthy' your waist measurement is. To view this product, please click here.
Once you have worked out your BMI, you can compare it to the following BMI Classification table:
|
BMI |
Classification |
|
<18.4 |
Underweight |
|
18.5 - 24.9 |
Healthy weight |
|
25.0 - 29.9 |
Overweight |
|
30.0 - 39.9 |
Obese |
|
40.0+ |
Morbidly obese |
It is important to recognise the dangers of being underweight as well as those of being overweight or obese. Although much of the focus is on reducing weight and body fat levels, it is possible to have too little fat in the body and this can cause endocrine, reproductive, digestive and cardiovascular complications.
Often a person being underweight is associated with them having an eating disorder. Although it can be a warning sign of eating disorders, it is important not to jump to any conclusions as there are many other reasons why an individual may have a low body weight.
Recent research has indicated that, for those in the lower end of the overweight category (BMI <27), the health risks are no greater than for those with a BMI in the healthy category – in fact, they may even be lower.
However, it is widely accepted that, as BMI increases above this level, the risk of all-cause mortality increases exponentially. If you are want to reduce your BMI click here to go to find out how to do it.
Circumference measurements
These can be taken around any limb or section of the trunk of the body. The recognised circumference measurement sites along with reasons for their measurement are listed below:
- Head – used with babies & children to monitor growth
- Neck – used by bodybuilders & athletes, for shirt sizing and in sleep apnoea patients
- Shoulders –used by bodybuilders & athletes
- Chest/ bust – used by bodybuilders & athletes, for bra sizing and in weight management
- Mid biceps – used by bodybuilders & athletes
- Waist – used for health screening, in weight management and by bodybuilders
- Hips – used for health screening, in weight management and by bodybuilders
- Mid thigh – used in weight management and by bodybuilders & athletes
- Mid calf – used in weight management and by bodybuilders & athletes
Waist & hip measurements
Of the above cicrumferences, it is the waist and hip measurements that are of most interest in terms of health. Waist measurement alone is an excellent indicator of cardiovascular disease risk because it reflects ‘abdominal obesity’.
The fat stored around the waist is called ‘visceral fat’ and it is more problematic than the fat stored under the skin. Visceral fat surrounds our organs and can impede their optimal functioning increasing the risk of conditions such as diabetes, certain cancers and cardiovascular disease.
This video demonstrates how to take your waist measurement correctly.
A recent study (2008) has emphasised the importance of waist measurement as an indicator for health risks. It showed that:
-
Men with waist measurements above 47 inches (119cm) are twice as likely to die early compared to those with waists smaller than 31.5 inches (80cm)
-
Women with waist measurements above 39 inches (99cm) have double the death rate of those with measurements below 25.5 inches (64.7cm)
-
An increase of 2 inches (5cm) on your waist measurement increases the chance of early death by 17% for men and 13% for women when BMI is unchanged
The following table identifies 'risk' associated with waist measurement.
|
Gender |
Male |
Female |
|
Low Risk |
<31.5 inches 80cm |
<25.5 inches <65cm |
|
Increased Risk |
31.5-39.8 inches 80-101cm |
25.5-34.3 inches 65-87cm |
|
Moderate Risk |
39.9-47.0 inches 102-119cm |
34.4-39.0 inches 88-99cm |
|
High Risk |
>47.0 inches >119cm |
>39.0 inches >99cm |
Hip measurement can be used in conjunction with waist measurement to calculate Waist to Hip Ratio (WHR) which is another way to identify risk of cardiovascular disease.
WHR = Waist measurement / Hip measurement
The following table identifies WHR associated with high risk of heart disease.
|
Gender |
WHR |
|
Male |
>1.0 |
|
Female |
>0.9 |
An increase of 0.1 in WHR suggests a third extra risk of death for men within the WHR range of 0.78 and 1.10 and quarter extra risk of death for women within the WHR range of 0.66 and 0.98.
Body composition
Body composition refers to how much of your body is fat mass and how much is lean mass (muscle, bone, water etc) and there are several ways of measuring it. All methods are ‘indirect’ as it is impossible to measure the absolute amount of fat and lean tissue in a live person!
The age-old gold standard measurement of body composition is hydrostatic (underwater) weighing, however this is an inaccessible and expensive option as are some of the new high-tech methods such as MRI scanning. The more common, easily accessible methods of assessing body composition are skinfold calliper measurements and bioelectrical impedance analysis (BIA).
BIA involves passing a very small electrical current through the body between two electrodes – often on a pair of weighing scales. By inputting information including height, age, gender and the weight measured by the scales, the raw impedance data is converted into a percentage of body fat.
Depending upon the scales being used, other measurements that may be generated include percentage of body water (hydration status), visceral fat level, metabolic rate and skeletal muscle mass. Omron’s BF500 body composition monitor is an accurate, inexpensive analyser for assessing body composition, visceral fat level and metabolic rate at home, click here to view this product.
It is useful to know your body fat percentage as it allows you to compare it against population norms for people of the same age and gender. Also, monitoring body composition change over time is useful for weight management purposes as it means that it is possible to ensure that the weight being lost is from fat loss rather than lean body mass loss.
In general, healthy body fat for men is between 10% and 18% and for women it is between 20% and 28%. The following table shows population norms for body composition:
|
Female (yrs) |
18-25 |
26-35 |
36-45 |
46-55 |
56-65 |
|
Lean |
<20 |
<21 |
<23 |
<25 |
<26 |
|
Average |
24-25 |
24-26 |
27-29 |
29-31 |
31-33 |
|
Fat |
29-31 |
31-35 |
33-36 |
35-38 |
37-38 |
|
Over fat |
>33 |
>36 |
>37 |
>39 |
>39 |
|
Male (yrs) |
18-25 |
26-35 |
36-45 |
46-55 |
56-65 |
|
Lean |
<10 |
<15 |
<18 |
<20 |
<21 |
|
Average |
14-18 |
19-21 |
22-24 |
24-25 |
25-26 |
|
Fat |
22-26 |
25-28 |
27-29 |
29-31 |
28-31 |
|
Over fat |
>28 |
>29 |
>31 |
>32 |
>32 |
How do I improve my measurements?
The good news is that BMI, waist measurement, WHR and body composition can all be improved in the same simple way - losing fat mass.
Losing weight from fat is best achieved through a combination of calorie controlled, healthy eating and increasing activity levels through lifestyle activity or exercise.
Diets that promote rapid weight loss are a very poor way to improve your measurements because the initial weight loss is often as much due to a loss in lean body mass (muscle tissue) as it is due to a loss in fat mass. The result of this type of weight loss is a reduction in your resting metabolic rate (the number of calories that you burn at rest) meaning that you don’t need as many calories as you did prior to the diet.
Returning to a normal eating pattern after rapid weight loss will cause an equally, or more, rapid re-gain of weight. However, more of your total body weight would now be fat so body composition and waist measurement are often worse! This common scenario repeated over time sets up what is known as the ‘yo-yo dieting cycle’ as demonstrated below.
Yo-yo dieting is not only an ineffective way to lose weight, it is also dangerous and repeated weight loss and gain can lead to liver problems, heart disease, hypertension, stroke & diabetes as well as a permanently lowered metabolism.
Redressing the balance
The safer, more effective alternative to weight loss is to modify your current eating habits a little at a time to reduce the amount of energy you take in. At the same time, increase your daily activity levels to expend more energy and you will shift from a positive energy balance to a negative energy balance.
- Positive energy balance is when more calories per day are being consumed than being used resulting in weight gain
- Negative energy balance is when fewer calories per day are being consumed than being used resulting in weight loss
The energy deficit which results from sensible negative energy balance is made up by your body’s energy reserves, primarily from its fat stores.
The energy balance principle is what BlueSkies tried and tested weight management programmes and dietary analysis services are based upon. Our programmes result in a steady but definite long-term weight loss from fat, whilst maintaining as much of your lean mass as possible.
Further information
To go the other pages in this series, please click on the appropriate topic below:
For more information on how to make the modifications that will help you to improve your anthropometric profile click here. You will be taken to the Member's Area of the BlueSkies website and will need your Member's Password to gain access.
If you are a BlueSkies Member, your password will have been e-mailed to you when you joined. If you have forgotten your password, please click here to receive your password reminder by e-mail.
If you have recently taken part in a BlueSkies Health MOT, you will have been given a temporary password to allow you to access this information. If you have forgotten your password, please contact the person within your organisation who organised the BlueSkies Health MOT. Alternatively, please e-mail us by clicking here and telling us where and when you had your Health MOT.
If you would like to become a BlueSkies Member, please click here for more information.
NB The information on this page should not supersede that given by your GP or medical professional.