Measures of Obesity

• Body Mass Index (BMI), which is a measure for indicating nutritional status in adults, is calculated as the weight in kilograms divided by the height in meters squared (kg/m²). The risk of premature death and many serious diseases increase with higher value of BMI.¹

Obesity classification is based on BMI (Body Mass Index) values as depicted in Figure 1.¹

Figure 1. Obesity classification based on BMI values¹

BMI ranges for normal weight are between 18.5 to 24.9 kg/m².¹ The widely accepted BMI cut points define individuals as:¹

• Overweight if they have a BMI of 25–29.9 kg/m²
• Obese if they have a BMI ≥ 30 kg/m²

The below table describes overweight and obesity classifications by BMI and waist circumference, and provides associated disease risk for type 2 diabetes, hypertension, and Cardiovascular Diseases (CVD).⁶

Measures of Abdominal Obesity

Increasing evidence suggests that abdominal obesity, rather than total body fat, is a predictor of obesity-related morbidity and mortality. ² Three measures of abdominal obesity are:

• Waist circumference measured in the horizontal plane midway in the distance of the superior iliac crest and the lower margin of the last rib, with a tape measure³

• Waist circumference is considered the most practical measure of abdominal fat. Excess abdominal fat is associated with greater health risks than fat in peripheral regions of the body.³
• The greater the waist circumference, the greater the risk of cardiovascular disease.⁴

How to measure your waist circumference in an accurate way.

First of all you need to:

• Make sure you have a measuring tape of the right length (preferably 200 cm long)
• Take the measurement at the widest lateral extension of the hips
• Stand free, in a light straddle position and relax

Then the correct waist circumference measurement is performed as following

1. Locate the upper edge of the hip plate (superiors iliac crest) and the lower edge of the last rib arch
2. Carry the tape measure half way between these points, make sure the tape is horizontal to the ground, adhere to the skin, but does not compress the belly 
3. Complete 2-3 normal breaths and measure at the end of normal exhalation

• Hip circumference measured at the level of the anterior superior iliac spine, where this can be felt, otherwise at the broadest circumference below the waist⁴. Measurement should be taken around the widest portion of the buttocks.

How to measure your hip circumference in an accurate way.

• Locate the greater trochanter (The greater trochanter of the femur is a large, irregular, quadrilateral eminence of the bone on the upper lateral part of the hip)
• Take the measurement at the widest lateral extension of the hips
• Ensure that the tape measure is horizontal
• Measure and state the measurement correctly to the nearest centimeter

• Waist-to-hip ratio (WHR), obtained by measuring the circumference of the waist divided by the measured circumference of the hip.⁵ The below table show the World Health Organization (WHO) cut-off points and risk of metabolic complications as a result of the findings following the WHR measurement.⁷

References