Associations Between Physical Activity and BMI, Body Fatness, and Visceral Adiposity in Overweight or Obese Latino and Non-Latino Adults

BACKGROUND/OBJECTIVES: Although several studies have reported associations between moderate to vigorous physical activity (MVPA), body fatness, and visceral adipose tissue (VAT), the extent to which associations differ among Latinos and non-Latinos remains unclear. The present study evaluated the associations between body composition and MVPA in Latino and non-Latino adults. SUBJECTS/METHODS: An exploratory, cross-sectional analysis was conducted using baseline data collected from 298 overweight adults enrolled in a 12-month randomized controlled trial that tested the efficacy of text messaging to improve weight loss. MVPA, body fatness and VAT were assessed by waist-worn accelerometry, DXA, and DXA-derived software (GE CoreScan GE, Madison, WI) respectively. Participants with less than 5 days of accelerometry data or missing DXA data were excluded; 236 participants had complete data. Multivariable linear regression assessed associations between body composition and MVPA per day, defined as time in MVPA, bouts of MVPA (time per bout ≥10 min), non-bouts of MVPA (time per bout <10 min), and meeting the 150-minute MVPA guideline. The modifying influence of ethnicity was modeled with a multiplicative interaction term. RESULTS: The interaction between ethnicity and MVPA in predicting percent body fat was significant (p = 0.01, 95% CI [0.58, 4.43]) such that a given increase in MVPA was associated with a greater decline in total body fat in non-Latinos compared to Latinos (adjusted for age, sex and accelerometer wear time). There was no interaction between ethnicity and MVPA in predicting VAT (g) (p = 0.78, 95% CI [−205.74, 273.17]) and BMI (p = 0.18, 95% CI [−0.49, 2.26]). CONCLUSIONS: An increase in MVPA was associated with a larger decrease in body fat, but neither BMI nor VAT, in non-Latinos compared to Latinos. This suggests that changes in VAT and BMI in response to MVPA may be less influenced by ethnicity than is total body fatness.