WHAT IS ANTHROPOMETRY?
Anthropometric!! Big word right, but these are measurements that are used to assess the size, shape and composition of the human body.
Anthropometry is the external measurement of the human body composition, it’s important in assessing nutritional status, it reflects both health and nutritional status, and it can predict performance, health and survival.
Measures taken include weight, height, Body Mass Index (BMI), Waist circumference, Waist to Hip Ratio (WHR) and Body Fat.
You might be forgiven to think that in your weight loss journey, your weight loss or gain is the only true measurement you need. However, the scales do not tell you if your weight is healthy or unhealthy, do not tell you where your weight is – which is the biggest danger – and it does not account for muscle mass.
Does that mean you should throw away your brand new digital scales? No, it just means that you should be aware of the following measurements and their usefulness.
For instance small, slender people who don’t weigh much may actually have a greater percentage of body fat than larger, more muscular people who weigh more. That’s just one reason why your weight on the scale doesn’t necessarily measure the level of your health.
Whether you’re trying to lose 5 pounds or 50, tracking your weight loss helps keep you motivated. It helps you keep track of your progress toward your ultimate goals, even if you’re not seeing huge results in the mirror from day to day. While you can measure the pounds you lose, you can also count the percentage of weight you shed. It’s easy to calculate your weight loss percentage at home, using pen and paper or a calculator.
Total Weight Loss Percent =
[ (Starting weight – Current weight) / Starting weight ] x 100.
For example –
[ (162lbs – 124lbs) / 162 ] x 100
(38 /162) x 100 = 23.4% weight loss
While it’s easy to figure out your percentage of weight loss, not all of that weight necessarily comes from fat. While you’ll lose fat as you shed weight, you might also lose water weight and muscle tissue. That means that your percentage of fat loss might be different from your overall weight loss. This is especially true for those that lose weight via fad dieting, which means you’ll generally lose more muscle than when you lose fat in a slow-and-steady manner.
Knowing how tall you are is very important in measuring one’s Body Mass Index. Your height is best measured using a stand-alone stadiometer or one fixed to the wall.
Alternatively, you could stand straight against a wall, heels back, and head straight while someone marks the wall at the top of your head. A tape measure can then be used to measure from the floor to where the mark is.
BODY MASS INDEX (BMI)
Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults. It is defined as the weight in kilograms divided by the square of the height in metres (kg/m2).
For example, an adult who weighs 70kg and whose height is 1.75m will have a BMI of 22.9.
BMI = 70 kg / (1.75 m2) = 70 / 3.06 = 22.9
BMI is a good way to determine if ones weight is healthy; it’s quick, simple and effective. However, it does not take muscle mass into account and it’s not a measure of body fatness. Also, it does not take into account excessive abdominal fat which can be detrimental to health
Table 1: The International Classification of adult underweight, overweight and obesity according to BMI
|Principal cut-off points||Additional cut-off points|
|Moderate thinness||16.00 – 16.99||16.00 – 16.99|
|Mild thinness||17.00 – 18.49||17.00 – 18.49|
|Normal range||18.50 – 24.99||18.50 – 22.99|
|23.00 – 24.99|
|Pre-obese||25.00 – 29.99||25.00 – 27.49|
|27.50 – 29.99|
|Obese class I||30.00 – 34.99||30.00 – 32.49|
|32.50 – 34.99|
|Obese class II||35.00 – 39.99||35.00 – 37.49|
|37.50 – 39.99|
|Obese class III||≥40.00||≥40.00|
Source: Adapted from WHO, 1995, WHO, 2000 and WHO 2004.
Measuring your waist is a good way to check you’re not carrying too much fat around your stomach, which can raise your risk of heart disease, Type 2 diabetes and stroke. You can have a healthy BMI and still have excess tummy fat meaning you’re still at risk of developing these diseases.
How to Measure –
- Measure at halfway point between lowest rib and hip bone (if you can not find this point measure at the “fattest” part of your tummy which is usually around your belly button
- Use a tape measure and measure against skin
- Breathe out and relax
- Don’t hold the tape tightly around tummy. It should be snug but not tight
- Record measurements particularly as you lose weight
Regardless of your height or BMI, you should try to lose weight if your waist is:
94cm (37ins) or more for men
80cm (31.5ins) or more for women
Table 2: Waist Girth and Health Risk
|Waist Girth and Health Risk|
|Normal||78 – 94cm||64 – 80cm|
|Overweight (elevated risk)||94 – 102cm||80 – 88cm|
|Obese (High risk)||>102cm||>88cm|
WAIST TO HIP RATIO (WHR)
This is calculated by dividing the circumference of the waist by the circumference of the hips. The measurement provides an assessment of abdominal fat (belly fat).
To calculate your waist-to-hip ratio you need to:
- measure your hips
- measure your waist
- divide the waist number by the hip number
waist / hip = WHR
A ratio of 0.9 or more in men or 0.85 or more in women indicates you are carrying too much weight around your middle. This puts you at increased risk of diseases linked to obesity, such as Type 2 diabetes and heart disease.
Table 3: Waist to Hip Ratio
|Waist to Hip Ratio|
|Man||≥0.90||Increased health risk
|Woman||≥0.85||Increased health risk
Belly fat can be lost through a combination of diet and exercise. You should avoid energy-rich/nutritionally poor goods, such as processed food and alcohol. Foods with plenty of fibre are a good alternative, as fibre can make you feel fuller with fewer calories.
BODY FAT PERCENTAGE (BFP)
This is the total mass of fat divided by total body mass; body fat includes essential body fat and storage body fat. Essential body fat is necessary to maintain life and reproductive functions. The percentage of essential body fat for women is greater than that for men, due to the demands of childbearing and other hormonal functions. The body fat percentage is a measure of fitness level, since it is the only body measurement which directly calculates a person’s relative body composition without regard to height or weight. It is how much of your body is composed of fat (adipose tissue) and how much of your body is composed of muscle, bone, internal organs, skin, tissue, hair, etc.
There are various ways to measure body fat percentage such as Bioelectrical Impedance Analysis (BIA), Infrared Analysis on the Bicep, Skin Fold Calipers, Hydrostatic Weighing, and an online body fat calculator. Apart from the online body fat calculator, all other methods should be done by a professional.
Table 3: Body Fat Percentage Categories
Body Fat Percentage Categories
|Classification||Women (% Fat)||Men (% Fat)|
|Obese||32% +||25% +|
Lean/Fat Mass –
Fat mass: Weight x body fat percentage
Lean mass: Weight – (weight x body fat percentage)
The number obtained can be used to gauge progress, because the scale doesn’t always tell the whole story. You might be losing weight or gaining weight, but where is that weight coming from. Is it muscle or fat?
Knowing your ratio of fat mass to lean mass will make it easier to determine how many pounds of fat you can likely lose each week. For instance, if you have a goal to lose 15 pounds in three months, knowing what percentage of your body composition is actually fat can help you decide whether that goal is reasonable.
Changes in your fat and lean mass weight can also allow you to make smart decisions about your weight loss plan. For example, if you lose lean mass, it could mean that you would need to re-check your nutritional intake or that you may be training way too much.