Physical Activity and Adiposity in a Racially Diverse Cohort of US Infants

Abstract

Objective Early life physical activity may help prevent obesity, but objective quantification in infants is challenging. Methods A total of 506 infants were examined from 2013 to 2016. Infants wore accelerometers for 4 days at ages 3, 6, 9, and 12 months. Daily log‐transformed physical activity counts were computed, averaged, and standardized across assessments. A linear mixed model was used to examine trends in standardized physical activity counts as well as associations between physical activity and BMI z score, sum of subscapular and triceps skinfold thickness for overall adiposity (SS+TR), and their ratio for central adiposity (SS:TR). Results Among infants, 66% were black and 50% were female. For each additional visit, standardized physical activity counts increased by 0.23 (CI: 0.18 to 0.27; P < 0.0001). This translates to 126.3 unadjusted physical activity counts or a 4% increase for each visit beyond 3 months. In addition, a 1‐SD increase in standardized physical activity counts (550 unadjusted physical activity counts) was associated with a 0.01‐mm lower SS:TR (95% CI: −0.02 to −0.001; P = 0.03). However, standardized physical activity counts were not associated with BMI z score or SS+TR. Conclusions Physical activity increased over infancy and was associated with central adiposity. Despite limitations, researchers should consider objective measurement in infants.

A qualitative study reporting maternal perceptions of the importance of play for healthy growth and development in the first two years of life

“…Indeed, it has been established that infants who are unwell, or undernourished are less physically active, and that activity improves with nourishment and improved health [9,10]. Furthermore, physical activity in infancy has been associated with decreased adiposity, and with optimal BMI [11][12][13]. Therefore, these perceptions are intuitive and factually correct.…”

Fetal programming of human energy homeostasis brain networks: Issues and considerations

“…With respect to PAL, actigraphy devices are a common method for determination in pediatric samples as they are relatively inexpensive, reliable, and convenient, making them highly accessible in a research context. Recent improvements in wearable devices for infants have also begun to provide insights into the role of early life PAL in typical growth trajectories 277,278 . As a proxy, when included with TEE, SMR can also be used to objectively estimate PAL 279,280 in early life by assuming that variation in WEE is principally driven by variation in PAL.…”

Association Between Age of Achieving Gross Motor Development Milestones During Infancy and Body Fat Percentage at 6 to 7 Years of Age

“…Achieving gross motor milestones at later ages were associated with lower levels of physical activity in infants and toddlers (Hnatiuk et al, 2013;Prioreschi et al, 2017). Additionally, physical activity was associated with central adiposity in infants (Benjamin Neelon et al, 2020). Therefore, achieving these milestones later is likely to be associated with physical inactivity during preschool years and may, thereby, cause subsequent body fat accumulation.…”