It is well known that BMI (Body Mass Index) is the most reliable measure for assessing body weight status and predicting complications. However, BMI is only a global value that does not take into account the different individual characteristics such as the distribution of fat in the body. This is why measuring waist circumference is so useful and provides vital information in addition to BMI.
What is waist circumference?
Waist circumference is a measurement of abdominal circumference to evaluate the intra-abdominal fat panicle (1). Waist circumference is a good indicator of health. Abdominal fat is the most dangerous part of the body. As a result, dozens of studies have looked at this index and have shown its correlation with several pathologies. Thus, two expert consensuses have been formed to define the size limits of the waist circumference. We will come back to this later on.
Why measure his waist circumference?
The main advantage of waist circumference is its independence from BMI. It makes it possible to detect possible pathologies (diabetes, hypertension, dyslipidemia, etc.) even in people with a normal or slightly increased BMI (2) (3). Moreover, it gives an absolute and real value of waist circumference and not a ratio, so it is not biased in very tall or overweight people.
Finally, there are significant variations in the distribution of fat according to ethnicity or even among individuals from the same society. The waist circumference, combined with the hip circumference, makes it possible to measure the waist-to-hip ratio and thus standardize the data.
How to measure your waist circumference?
Medical semiology books recommend taking your waist circumference with a tape measure halfway between the last rib and the pelvic bone, at the end of a normal exhalation, without applying pressure on the skin and without contracting your muscles (1). Most often the waist circumference is measured just above the navel. Measuring your waist circumference incorrectly can seriously distort the result and therefore the interpretation.
According to the expert consensus of the International Diabetes Federation (4), the tolerated threshold in Europe is 94 cm in men and 80 cm in women. However, another consensus, the Adult Treatment Panel Guidelines III (5), recommends 120 cm in men and 88 cm in women as the threshold, but this does not take ethnic differences into account.
Sources and references
(1) Précis of Semiology, Rose Marie Hamladji.
(2) Guidelines on Overweight and Obesity: Electronic Textbook. NIH
(3) Chan JM, Rimm EB, Colditz GA, Stampfer MJ, Willett WC
Obesity, fat distribution, and weight gain as risk factors for clinical diabetes in men. Diabetes Care. 1994;17:961-969.
(4) The IDF consensus worldwide definition of the metabolic syndrome
International Diabetes Federation. 8/3/2007
(5) Executive Summary of The Third Report of The National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, And Treatment of High Blood Cholesterol In Adults (Adult Treatment Panel III
JAMAICA 2001; 285: 2486-97.