Sedentary Time Patterns Among Preschoolers: Do Sex Disparities Exist?

Abstract

Background: Examining sedentary time (ST) by disaggregating the day into periods such as before, during, and after preschool allows interventionists to understand when sedentary behaviors are most severe. This study aimed to determine if there are sex differences in ST before, during, and after preschool hours in US preschoolers. Methods: A secondary analysis of a two-cohort study with a sample size of 292 preschoolers (67% African Americans/Blacks; 100% from low-income families) was used. Measures were collected in Fall 2017 and Fall 2018. Preschoolers wore an accelerometer on the non-dominant wrist for 8 consecutive days to obtain ST minutes before, during, and after preschool periods. Three separate linear regressions were conducted to test sex differences in ST before, during, and after preschool hours. ST for each period of the day was considered the outcome variable predicted by sex and covarying for BMI percentile. Results: Girls were more sedentary than boys during preschool (F (1, 226) = 5.15, p = 0.006; b = -0.09 [-0.15, -0.03]), but not before preschool (F(1, 225) = 0.98, p = 0.32; b = 2.50 [-2.46, 7.45]) nor after preschool (F(1, 227) = 3.62, p = 0.06; b = 6.60 [-0.21, 13.42]). Conclusions: This difference in ST could have an unfavorable health impact among preschool girls. Given that childhood obesity prevalence dramatically increases from preschool age to childhood, there is a need to design family-based interventions that provide parents/caregivers strategies to develop habits around healthy eating and physical activity that they can carry into later life stages.