24-h movement behaviors from infancy to preschool: cross-sectional and longitudinal relationships with body composition and bone health

• Main Authors: Rachael W. Taylor (Author), Jillian J. Haszard (Author), Kim A. Meredith-Jones (Author), Barbara C. Galland (Author), Anne-Louise M. Heath (Author), Julie Lawrence (Author), Andrew R. Gray (Author), Rachel Sayers (Author), Maha Hanna (Author), Barry J. Taylor (Author)
• Format: Book
• Published: BMC, 2018-11-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.1186/s12966-018-0753-6; 1479-5868
• Keywords: Physical activity; Sedentary behavior; Sleep; Children; Compositional time use; Nutritional diseases. Deficiency diseases; RC620-627; Public aspects of medicine; RA1-1270
• Source: International Journal of Behavioral Nutrition and Physical Activity, Vol 15, Iss 1, Pp 1-14 (2018)

Abstract Background New physical activity guidelines for children address all movement behaviors across the 24-h day (physical activity, sedentary behavior, sleep), but how each component relates to body composition when adjusted for the compositional nature of 24-h data is uncertain. Aims To i) describe 24-h movement behaviors from 1 to 5 years of age, ii) determine cross-sectional relationships with body mass index (BMI) z-score, iii) determine whether movement behaviors from 1 to 5 years of age predict body composition and bone health at 5 years. Methods 24-h accelerometry data were collected in 380 children over 5-7 days at 1, 2, 3.5 and 5 years of age to determine the proportion of the day spent: sedentary (including wake after sleep onset), in light (LPA) and moderate-to-vigorous physical activity (MVPA), and asleep (including naps). BMI was determined at each age and a dual-energy x-ray absorptiometry (DXA) scan measured fat mass, bone mineral content (BMC) and bone mineral density (BMD) at 5 years of age. 24-h movement data were transformed into isometric log-ratio co-ordinates for multivariable regression analysis and effect sizes back-transformed. Results At age 1, children spent 49.6% of the 24-h day asleep, 38.2% sedentary, 12.1% in LPA, and 0.1% in MVPA, with corresponding figures of 44.4, 33.8, 19.8 and 1.9% at 5 years of age. Compositional time use was only related significantly to BMI z-score at 3.5 years in cross-sectional analyses. A 10% increase in mean sleep time (65 min) was associated with a lower BMI z-score (estimated difference, − 0.25; 95% CI, − 0.42 to − 0.08), whereas greater time spent sedentary (10%, 47 min) or in LPA (10%, 29 min) were associated with higher BMI z-scores (0.12 and 0.08 respectively, both p < 0.05). Compositional time use from 1 to 3.5 years was not related to future BMI z-score or percent fat. Although MVPA at 2 and 3.5 years was consistently associated with higher BMD and BMC at 5 years, actual differences were small. Conclusions Considerable changes in compositional time use occur from 1 to 5 years of age, but there is little association with adiposity. Although early MVPA predicted better bone health, the differences observed had little clinical relevance. Trial registration ClinicalTrials.gov number NCT00892983.