Determining the worldwide prevalence of obesity
The NCD Risk Factor Collaboration study (Dec 16, 2017, p 2627)1 is a
landmark description of the progress of the obesity pandemic, but
substantially underestimates the scale of the problem. The study defined obesity using body-mass index (BMI) in adults and BMI-for-age in children and adolescents. Systematic reviews of a large amount of high-quality and consistent evidence show that the use of BMI to define obesity (the degree of excess body fat) is highly specific, but
has low to moderate sensitivity. As a result, BMI-based estimates of obesity prevalence are highly conservative for all ages and both sexes.2–4 Around half of all adults with excess body fat are
defined as non-obese according to BMI, and at least 25–50% of children and adolescents defined as having a healthy BMI-for-age will also have excess body fat.3,4 These systematic reviews are based largely on evidence from European and western populations. In many other populations, the bias associated with the use of BMI is worse, leading to more pronounced underestimates of obesity prevalence, and complicating global comparisons. The inherent low sensitivity of BMI
as a means of defining obesity should be acknowledged when prevalence estimates are provided. Informed comparisons between the prevalence of underweight and the prevalence of obesity can only be made if the large biases in obesity estimates are considered. Substantial underestimates of prevalence could also hinder
future interventions aimed at obesity prevention and control. Obesity is far more common, and requires more urgent attention, than the NCD Risk Factor Collaboration study suggests.
Auteur(s) : Reilly JJ, El-Hamdouchi A, Diouf A, Monyeki A, Somda SA.
Pages : 1773-1774
Année de publication : 2018
Revue : The Lancet
N° de volume : 391
Type : Article
Mise en ligne par : DIOUF Adama