Trends in waist circumference - Obesity

BMI provides a measure of overall adiposity, but the distribution of adipose tissue in predicting health risks associated with obesity is also important. Abdominal fat deposition is generally considered a key component of obesity. Waist circumference is a convenient way of measuring abdominal fat deposition and may be a more useful measure of obesity than BMI is for several reasons. First, waist circumference is associated more strongly with risk factors of cardiovascular disease (CVD) and is as good or better predictor of future risk of the metabolic syndrome, type 2 diabetes, CVD and all-cause mortality. In addition, waist circumference is conceptually easy to measure and the public may understand waist circumference more easily than BMI.


Waist circumference data for National Health and Nutrition Examination Survey (NHANES) III have been described for subjects above 17 years of age. This study provides additional detail about the distribution of waist circumference in NHANES III, and examines changes in waist circumference among US adults from 1988 to 1994 through 1999 to 2000.

Data from 15, 454 subjects in NHANES III (1988 to 1994) and 4024 subjects from National Health and Nutrition Examination Survey 1999 to 2000 was used. The median waist circumference increased from 94.4 cm to 97.1 cm among men and from 86.6 am to 90.3 cm among women. The percentiles suggest that much of the waist circumference distribution has shifted. The prevalence of a high-risk waist circumference (greater than 102 cm in men and greater than 88 cm in women) increased between the two surveys in all subgroups except Mexican-American women. Among both men and women, the greatest increases in waist circumference occurred among those between 20 to 39 years of age.

These results demonstrate the rapid increase in obesity, especially abdominal obesity, among US adults. The findings suggest that unless measures are taken to slow the increase or reverse the course of the obesity epidemic, the burden of obesity-associated morbidity and mortality in the United States, could be expected to increase substantially in future years. One obstacle is that, it is unclear how commonly clinicians measure waist circumference. Anecdotal evidence suggests that it is not practised routinely. Although measuring waist circumference correctly requires practice, health care professionals are urged to incorporate waist circumference along with measuring weight and height in their routine practice.

What Obesity Stands for

Obesity is a "condition characterized by an excess of body fat distributed across the board in various areas of the body fat. Definition taken from the Dictionary of Medicine Flammarion. In most cases, obesity is assessed by the weight it should be noted that there is no strict equivalence between weight and obesity because the weight involved, in addition to fat, bone, water and muscle.

Obesity is defined by a Body Mass Index (BMI). BMI is calculated by dividing the person's weight by the square of height (kg / m2). If this index is greater than or equal to 30, the individual is considered obese. Between 25 and 30, we talk about préobésité. From 40 kg / m2, we speak morbid obesity. This is the threshold at which we may see a morbidity secondary to different types of complications.