Selection of Sex Does Not Affect Body Composition When Using the InBody770 Bioelectrical Impedance Analysis Original Research

Abstract

Introduction: Many methods and equations for assessing body composition include sex as a variable.  However, sex and gender identity do not always align.  Thus, it would be beneficial to have easily performed methods of measuring body composition that did not rely on sex as a component of the assessment.  For this purpose, the current study tested whether the InBody770 requires sex input to accurately measure body composition in males and females.

Methods:  Cisgender men and women were recruited to the study to have their body composition assessed in duplicate.  Assessments were performed in a random order.  ANOVAs were performed on the data reported from the InBody770 both within subjects and between groups.

Results: There were no within subject differences for percent body fat (33.6 vs. 33.5 and 15.1 vs. 15.1%), estimated basal metabolic rate (1,438 vs. 1,440 and 1,842 vs. 1,842kcals/day), nor total body water (36.15 vs. 36.24 and 49.89 vs. 49.92 L) regardless of whether their sex was assigned as male or female. There were significant sex differences for percent body fat (33.5 vs. 15.1%), metabolic rate (1,438 vs. 1,842kcals), and total body water (36.15 vs. 49.92L regardless of how the individuals were identified (male or female).

Conclusions: While average sex differences in percent body fat existed between males and females, the imputation of sex on the InBody770 did not influence the data produced.