Direct and self-reported measures of physical activity and sedentary behaviours by weight status in school-aged children: results from ISCOLE-Kenya

Abstract

Background: Previous work has shown little association between self-report and directly measured physical activity. The objective of this study was to investigate the relationships between self-reported and directly assessed measures of physical activity and sedentary time by weight status in Kenyan children.

Methods: Direct assessment of body weight, physical activity and sedentary time of 563 children was collected through anthropometry and accelerometry, while self-reported assessment was achieved by administering a questionnaire.

Results: Under/healthy weight children had significantly higher directly measured mean daily minutes of moderate-to-vigorous physical activity (MVPA) compared to overweight/obese children (39 vs 20 minutes); had lower mean weekend-day minutes of sedentary time (346 vs 365 minutes); had a higher proportion who met accepted physical activity guidelines (15.3% vs 2.6%); and a higher number reported using active transportation to/from school (49.2% vs 32.4%). Self-reported time spent outside before and after school and active transport to/from school were significantly associated with mean weekday minutes of MVPA (r-value range = 0.12–0.36), but only for the under/healthy weight children.

Conclusions: The results of this study found a number of differences in the accumulation of MVPA and sedentary time by weight status and weak-to-moderate correlations between self-report and direct measures of weekday and weekend-day physical activity among the under/healthy weight children.

• Children
• direct-measures
• physical activity
• sedentary behaviours
• self-report

Acknowledgements

The authors are grateful to all participants of the ISCOLE-Kenya study and the research assistants who helped with data collection. We thank biostatistician Kathryn Williams for her guidance with statistical analysis for this manuscript. In addition, we would like to thank the ISCOLE Coordinating Center staff at the Pennington Biomedical Research Center for study co-ordination and data management (Peter T. Katzmarzyk, PhD, and Timothy S. Church, MD, principal investigators, and Denise Lambert, RN, project manager). ISCOLE is funded by the Coca-Cola Company. The funder had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. SKM, LMW, VOO and MST contributed to preparations prior to implementing the study protocol in Kenya. SKM and LMW participated in data collection and entry. SKM and MST analysed the data and interpreted the results. SKM led the writing of the manuscript. All authors contributed to the writing, editing and approved this manuscript.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.