title: Physical Activity is Associated with Percent Body Fat and Body Composition but not Body Mass Index in White and Black College Students.
abstract: The objective of this study was to examine the association of self-reported physical activity (PA) with body composition in 290 college students (49% male, 60% White) 18-25 years of age. Outcome measures included: self-reported PA levels calculated in MET-hrs·wk-1from the International Physical Activity Questionnaire (IPAQ); body mass index (BMI; in kg·m-2); and body composition variables estimated by dual-energy X-ray absorptiometry (DXA). Mean activity levels of the sample were 39.8 ± 23.8 MET-hrs·wk-1. Participants were divided into quartiles of PA levels: ≥0 to <24.0, ≥24.0 to <34.0, ≥34.0 to <51.25, and ≥51.25 MET-hrs ·wk-1and body composition variables were compared by group. Chi-square analyses revealed a significant difference for gender by PA quartile [χ2(3, N=290) = 32.42, p < 0.0001], and for gender by race by PA quartile [χ2(9, N=290) = 37.82, p < 0.0001]. MET-hrs·wk-1was inversely correlated with %BF (r= -0.40,p< 0.0001) but not BMI (r= 0.05,p= 0.43). When comparing body composition variables across PA quartiles, no significant differences were observed for BMI; however, subjects in the highest quartile of PA had a lower percent body fat (%BF) and fat mass (FM), and a higher lean-tissue mass (LTM) compared to subjects in the other three groups. In this cohort of young adults, participants in the highest activity group had a more fit body composition profile (e.g., lower %BF, lower FM, and higher LTM) which was not reflected in BMI and was independent of gender and race.
authors.affiliation: School of Human Ecology, Louisana State University Agcenter, Baton Rouge, LA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Zanovec
authors.affiliation: School of Human Ecology, Louisana State University Agcenter, Baton Rouge, LA, USA.
authors.forename: Anantha P
authors.initials: AP
authors.lastname: Lakkakula
authors.affiliation: Department of Kinesiology, Louisana State University, Baton Rouge, LA, USA.
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Johnson
authors.affiliation: School of Human Ecology, Louisana State University Agcenter, Baton Rouge, LA, USA.
authors.forename: Georgianna
authors.initials: G
authors.lastname: Turri
keywords: BMI; DXA; IPAQ; Physical activity; body composition; body fat; college students; ethnicity; race