一查文献,发现研究人员对这两种情况还真有一些探讨。老宋的朋友的情况很可能是“代谢肥胖而体重正常”(Metabolically obese normal weight);小庞的情况可能是“代谢正常却身体肥胖”(Metabolically healthy obese)。关于这方面的研究有一篇综述写得很好,我先摘要介绍一下 (14)。
韦伯氏字典关于肥胖的定义是身体里脂肪的过多积累和贮存。但临床关于肥胖与否的测量最初是量一定身高下的体重,后来发展成体重指数(BMI:Body Mass Index,体重/身高的平方,单位是公斤/平方米,大于25为超重,大于30为肥胖)。肥胖当然更应该用脂肪的含量来定义,比如脂肪含量超过体重的25%(男)或35%(女)为肥胖。但由于测BMI远远比测脂肪含量容易,所以BMI被广泛运用。有人对BMI正常的人的脂肪含量进行了测量,在男性中数据从5.6%到31.2%,在女性中从4.6%到51.1% (8)。所以用BMI来衡量肥胖是很不精确的。这很容易忽略了这样一些人:他们体重正常甚至偏瘦,BMI小于25,但脂肪含量却很高。这些人往往更容易得糖尿病与心血管疾病。
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感谢阅读留言,我有一位朋友也是骑车健身的,俺是非常佩服!