Waist Measurement

Original Editor - Lucinda Hampton

Top Contributors - Lucinda hampton, Boluwatife Williams and Chelsea Mclene  

Introduction

Waist measurement is a simple check to tell if you’re carrying excess body fat around your middle.

• Waist measurement is an indicator of the level of internal fat deposits that coat the heart, kidneys, liver, digestive organs and pancreas. 
• This can increase the risk of heart disease, stroke, type 2 diabetes and cancer.

There is now good evidence that central obesity carries more health risks compared with total obesity assessed by body mass index (BMI). It has been suggested that waist circumference (WC), a proxy for central obesity, should be included with BMI in a ‘matrix’ to categorise health risk.

BMI

Body mass index (BMI), is a measure for estimating total body fat and is calculated by dividing your weight in kilograms by your height in metres squared. But while it can be a useful tool, the distribution of fat on your body is more important than the amount when it comes to predicting health risks. A better measure of a weight problem eg obesity can be measured using a person’s waist circumference Or assess body composition.

Clinical Relevance

It’s not just how much fat you’re carrying on your body that matters to your health, where it is plays a key role too.

• Research shows that weight around the hips can actually provide some level of protection against disease, but carrying excess body fat around your middle has the opposite effect.
• Waist measurement can indicate how much internal fat is coating organs e.g. the liver, kidneys and heart, which increases the risk of heart disease, stroke, type 2 diabetes and cancer.

Official guidelines say regardless of your height, your health is at risk if your waist size is more than 94cm for men and 80cm for women.

Measuring the Waist

Waist Circumference (WC): To measure WC, patients should stand with their arms crossed on the contralateral shoulders. The placement of the measuring tape should be snugly around the lateral aspect of each ilium at the mid-axillary line. It is an essential measure of anthropometry in adults and children as it directly measures central adiposity. Increasing central adiposity is associated with an increased risk of morbidity and mortality due to an increased risk of diabetes and heart disease.

Your health is at risk if your WC is:

1. Men: Over 94cm (about 37 inches)
2. Women: Over 80cm (about 31.5 inches)

Waist to Hip Ratio

The waist-hip ratio (WHR) is used to assess obesity, which can be a sign of other serious health issues. According to the WHO, abdominal obesity is defined as a waist-hip ratio more than 0.90 for men and greater than 0.85 for women. For either sex, a ratio greater than 1.0 indicates a significantly increased risk of health issues.

The waist-hip ratio (WHR) is calculated by dividing the waist circumference (WC) by the hip circumference (HC), using the same measurement units for each (^WC⁄_HC). The WHO recommends measuring the hip circumference across the broadest part of the buttocks with the tape parallel to the floor and the waist circumference at the midline between the lower margin of the last palpable ribs and the top of the iliac crest.

Due to its poorer correlation with cardiovascular and metabolic risk factors than other clinical adiposity measurements, the WHR's clinical value has decreased in recent years. According to research, waist circumference (especially waist-to-height ratio) is a greater predictor of cardiovascular risk factors than waist-hip ratio.

Waist-to-hip ratio chart

Health risk	Women	Men
low	0.80 or lower	0.95 or lower
moderate	0.81-0.85	0.96-1.0
high	0.86 or higher	1.0 or higher

The video below demonstrates how to measure the waist and hip circumferences and determine the waist-hip ratio:

Waist to Height Ratio

Waist to height ratio (WHtR) is a better predictor of heart disease and diabetes risk than BMI. Keeping your WC to less than half your height can help increase life expectancy for every person in the world.

Examples:

1. A man who is 6ft or 72 inches tall (183 cm), should keep his waist under 36 inches (91 cm)
2. A woman who is 5ft 4 in or 64 inches tall (163 cm), should keep her waist measurement under 32 inches (81 cm).

The idea of using WHtR to predict cardiometabolic risk is not new, but is coming to prominence as more studies reveal its value.

Use of a simple boundary value for WHtR (0.5) identifies more people at ‘early health risk’ than does a more complex ‘matrix’ using traditional boundary values for BMI and WC. WHtR may be a simpler and more predictive indicator of the ‘early heath risks’ associated with central obesity.

Role of Rehabilitation Professionals

There are several roles to play in the rehabilitation management of obese clients, especially when it comes to prescribing exercise and mobility for illnesses connected to obesity.

These evaluations would assist rehabilitation professionals in identifying persons whose body weight places them at elevated health risk and would give opportunity to address regular physical activity and healthy lifestyles.