Because the index is calculated from two biological measures (weight and height), the resulting score has no biological meaning in itself. Thus, studies of the genetics of obesity that are based on a relationship between certain genetic markers and the BMI are also meaningless.
但这样的用法存在不小的局限。该指数由两项生物学指标（体重和身高）计算得出，因此算出的得分本身并不具有生物学意义。因此，基于特定遗传指标和体重指数关系的遗传学肥胖研究也没有什么意义。