Objective To analyze the accuracy of different BMI obesity screening criteria in discriminating the obesity of college students, and to provide a reference for formulation scientific and reasonable grouth and development evaluation criteria for students.
Methods The bioelectrical impedance analysis (BIA) was used to measure BF of 1 977 non-sports-major-students. Based on WHO “golden standard” of BF% (BF>25% for male and BF >35% for female) for obesity, the accuracy, reliability, and benefits of different BMI screening standards for obesity were evaluated.
Results The obesity rate was 11.6% according to the BF% standard, and was 2.0% and 8.2% based on BMI ≥28 kg/m 2 and BMI ≥25 kg/m 2, respectively; A higher specificity (0.999, 0. 966) and a low sensitivity (0.175, 0.450) were noticed when BMI ≥28 kg/m 2 and BMI ≥25 kg/m 2 was used as screening standard for obesity, especially among female (0.063, 0.304); The reliability evaluation of consistency with “gold standard” of BMI ≥25 kg/m 2 was higher than BMI ≥25 kg/m 2; when BMI ≥28 kg/m 2 was used as screening standard for obesity, the positive predictive value was higher than negative predictive value, BMI ≥25 kg/m 2 was on the contrary.
Conclusion BMI cannot adequately reflect body fat content of college students, especially for female; The standard for obesity diagnosis should be based on gender.
【摘要】目的分析不同体质量指数（body mass index,BMI)肥胖筛査标准判别大学生肥胖的准确性，为制定科学合 理的学生生长发育评判标准提供参考。 方法采用生物阻抗法（bioelectricalimpedanceanalysis，BIA)对北京体育大学非体 育专业1 977名大学生（男生1 320名，女生657名）进行体脂测定。以WHO推荐的体脂率肥胖判定标准（男>25%，女> 35%)作为“金标准”，分别对不同BMI筛査标准的真实性、可靠性、收益等进行评价。 结果以体脂率判定标准检出的肥 胖率为11.6%;分别以BMI ≥28 kg/m 2，BMI ≥25 kg/m 2为肥胖判定标准时，肥胖检出率分别为2.0%，8.2%;BMI ≥28 kg/m 2，BMI ≥25 kg/m 2作为大学生肥胖筛査标准的真实性评价结果为特异度髙（0.999和0.966)、灵敏度过低（0.175和 0.450)，尤其是女生（0.063和0.304)；尺印斤分析表明，BMI ≥25 kg/m 2与体脂率“金标准”一致性比BMI ≥28 kg/m 2髙，分 别为0.477和0.269;BMI ≥28 kg/m 2阳性预测率比阴性预测率髙，BMI ≥25 kg/m 2阴性预测率比阳性预测率髙。 结论 BMI不能客观反映大学生的体脂含量，尤其对女大学生；建议分性别制定BMI肥胖判定标准。