title: Are BMI and Sedentariness Correlated? A Multilevel Study in Children.
abstract: The purpose of this research was to investigate the relationship between body mass index (BMI) and sedentariness (Sed) in children and to examine the influence of child and school correlates on their variation. The sample comprises 580 children (337 girls, 9-11 years). Sedentariness was assessed with an accelerometer, and BMI was computed. Child- and school-level covariates were analyzed using multilevel models. No significant correlation between Sed and BMI was found. School context explains 5% and 1.5% of the total variance in Sed and BMI, respectively. At the child level, only moderate-to-vigorous physical activity was associated with both Sed (β = -0.02 ± 0.002) and BMI (β = -0.005 ± 0.002). Sleep time is related to Sed (β = -0.42 ± 0.04), while sex (β = 1.97 ± 0.13), biological maturity (β = 1.25 ± 0.07), media in the bedroom (β = 0.26 ± 0.08) and healthy (β = -0.09 ± 0.03) and unhealthy (β = -0.07 ± 0.04) diet scores were associated with BMI. None of the school-level covariates were related to BMI, but access to cafeteria (β = -0.97 ± 0.25), playground equipment (β = -0.67 ± 0.20) and restaurants (β = 0.16 ± 0.08) were related to Sed. In conclusion, Sed and BMI were not correlated. Further, they have different correlates, while children's traits seem to play more relevant roles in their differences in Sed and BMI than the school milieu. This information should be taken into account when strategies to reduce Sed and BMI are implemented.
authors.affiliation: Center of Research, Education, Innovation and Intervention in Sport (CIFI2D), Kinanthropometry Lab, Faculty of Sport, University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal. thayse_natacha@hotmail.com.
authors.forename: Thayse Natacha
authors.initials: TN
authors.lastname: Gomes
authors.affiliation: Pennington Biomedical Research Center, Louisiana State University, 6400 Perkins Rd, Baton Rouge, LA 70808-4124, USA. Peter.Katzmarzyk@pbrc.edu.
authors.forename: Peter T
authors.initials: PT
authors.lastname: Katzmarzyk
authors.affiliation: Department of Physical Education and Sports Science, CAV, Federal University of Pernambuco (UFPE), Rua Alto do Reservatório, Bela Vista, 55608-680 Vitória de Santo Antão, PE, Brazil. fernandak.santos@hotmail.com.
authors.forename: Fernanda Karina
authors.initials: FK
authors.lastname: dos Santos
authors.affiliation: Federal University of Technology-Paraná (UTFPR), Campus Curitiba, 80230-901 Curitiba, PR, Brazil. raquelnichele@live.com.pt.
authors.forename: Raquel Nichele
authors.initials: RN
authors.lastname: de Chaves
authors.affiliation: Center of Research, Education, Innovation and Intervention in Sport (CIFI2D), Kinanthropometry Lab, Faculty of Sport, University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal. d.monteiro.santos13@gmail.com.
authors.forename: Daniel
authors.initials: D
authors.lastname: Santos
authors.affiliation: Center of Research, Education, Innovation and Intervention in Sport (CIFI2D), Kinanthropometry Lab, Faculty of Sport, University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal. sara.s.p@hotmail.com.
authors.forename: Sara
authors.initials: S
authors.lastname: Pereira
authors.affiliation: Pennington Biomedical Research Center, Louisiana State University, 6400 Perkins Rd, Baton Rouge, LA 70808-4124, USA. catherine.champagne@pbrc.edu.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Champagne
authors.affiliation: Department of Public Health Sciences, University of Chicago Biological Sciences, 5841 S. Maryland Ave, Room W254, MC2000, Chicago, IL 60637, USA. DHedeker@health.bsd.uchicago.edu.
authors.forename: Donald
authors.initials: D
authors.lastname: Hedeker
authors.affiliation: Center of Research, Education, Innovation and Intervention in Sport (CIFI2D), Kinanthropometry Lab, Faculty of Sport, University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal. jmaia@fade.up.pt.
authors.forename: José
authors.initials: J
authors.lastname: Maia
mesh_terms: D015992:Body Mass Index; D002648:Child; D015444:Exercise; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D011174:Portugal; D012574:Schools; D057185:Sedentary Behavior; D012959:Socioeconomic Factors
keywords: BMI; children; multilevel analysis; sedentariness