Milanese Chiara, Itani Leila, Cavedon Valentina, El Ghoch Marwan
Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37129 Verona, Italy.
Department of Nutrition and Dietetics, Faculty of Health Sciences, Beirut Arab University, Riad El Solh, Beirut P.O. Box 11-5020, Lebanon.
Nutrients. 2025 Jun 29;17(13):2162. doi: 10.3390/nu17132162.
: The body mass index (BMI) is considered a key method for the classification of individuals' weight status, according to cut-off points proposed by the World Health Organization (WHO); however, the use of this classification is still the subject of debate and criticism. We aimed to evaluate the accuracy of the WHO BMI classification in reflecting true adiposity in the Italian general population. : This cross-sectional study included 1351 adults of mixed gender aged between 18 and 98 years, comprising 19 (1.4%) underweight individuals, 787 (58.3%) normal weight, 354 (26.2%) overweight, and 191 (14.1%) with obesity according to the WHO BMI. After that they were re-categorized according to adiposity based on body fat percentage (BF%) measured by dual-energy X-ray absorptiometry (DXA). The agreement between the two classification systems was tested using the kappa statistic (κ), with the system based on BF% being considered the gold standard. : According to the BMI classification, 78.1% of the individuals who were in the normal weight range were correctly classified. However, 53.4% of the overweight group and 68.4% of the underweight group were misclassified according to the BMI, as the majority of those misclassified fell within the normal weight range according to their BF%. Finally, regarding the obesity group, 34% who were classified as having obesity according to the BMI were misclassified, since they were revealed to be only affected by overweight according to adiposity status. : Despite the fact that the BMI seems to be reliable in determining body weight status in the normal weight range, over a third of the general population was misclassified, as the current BMI classification appears to inflate the prevalence of underweight, overweight, and obesity among the general population. Accordingly, this may warrant consideration of revising the National Guidelines in Italy related to weight status classification. Healthcare practitioners should be advised not to rely solely on the BMI, and should integrate its use with adiposity measures (i.e., BF%) or alternative surrogate indicators (i.e., waist-based) in routine evaluations, especially in those with a BMI below or above 18.5 kg/m or 25 kg/m.
根据世界卫生组织（WHO）提出的切点，体重指数（BMI）被视为对个体体重状况进行分类的关键方法；然而，这种分类方法的使用仍然存在争议和批评。我们旨在评估WHO的BMI分类在反映意大利普通人群真实肥胖程度方面的准确性。
这项横断面研究纳入了1351名年龄在18至98岁之间的成年男女，根据WHO的BMI标准，其中19人（1.4%）体重过轻，787人（58.3%）体重正常，354人（26.2%）超重，191人（14.1%）肥胖。之后，根据通过双能X线吸收法（DXA）测量的体脂百分比（BF%）对他们进行肥胖程度重新分类。使用kappa统计量（κ）检验两种分类系统之间的一致性，以基于BF%的系统作为金标准。
根据BMI分类，体重正常范围内的个体中有78.1%被正确分类。然而，根据BMI标准，超重组中有53.4%以及体重过轻组中有68.4%被错误分类，因为大多数被错误分类的人根据其BF%属于体重正常范围。最后，关于肥胖组，根据BMI被分类为肥胖的人中有34%被错误分类，因为根据肥胖状况显示他们仅受超重影响。
尽管BMI在确定体重正常范围内的体重状况时似乎是可靠的，但超过三分之一的普通人群被错误分类，因为目前的BMI分类似乎高估了普通人群中体重过轻、超重和肥胖的患病率。因此，这可能需要考虑修订意大利与体重状况分类相关的国家指南。应建议医疗从业者不要仅依赖BMI，并且在常规评估中应将其与肥胖程度测量（即BF%）或替代指标（即基于腰围的指标）结合使用，特别是对于BMI低于或高于18.5kg/m²或25kg/m²的人群。
