Background: This study reported compliance with 24-hour physical activity and sedentary behavior guidelines, and associations with adiposity in the first 2 years of life. Methods: Participants (N = 119) were recruited from Soweto, South Africa. Visceral and subcutaneous abdominal adipose tissue was measured by ultrasound. Participation in 2 movement behaviors (physical activity and sedentary time) was reported by mothers. Differences in adiposity between those meeting each individual guideline, as well as the combination of both movement guidelines, compared with those not meeting the guidelines were assessed. Results: Only 5% of infants met the sedentary guidelines; however, 58% met the physical activity guidelines. Subcutaneous adipose tissue was significantly higher in those meeting the physical activity guideline (0.50 [0.01] vs 0.47 [0.01] cm, P = .03) compared with those not meeting the guideline. Meeting the screen time component of the sedentary guideline was associated with higher visceral adipose tissue (β = 0.96, P < .01), while meeting one guideline compared with meeting none was associated with higher subcutaneous adipose tissue (β = 0.05, P = .01). Conclusions: Most infants and toddlers from this low- to middle-income setting were not meeting sedentary behavior guidelines. Both behaviors were associated with abdominal adiposity, but not with body mass index z score; implying these movement behaviors may impact abdominal fat deposition rather than body size.
Alessandra Prioreschi and Lisa K. Micklesfield
Simone A. Tomaz, Alessandra Prioreschi, Estelle D. Watson, Joanne A. McVeigh, Dale E. Rae, Rachel A. Jones and Catherine E. Draper
Background: Limited research reports on the relationship between body mass index (BMI) and physical activity (PA), sedentary behavior (SB), sleep, and gross motor skills (GMS) in low- and middle-income countries. The aim of this study was to (1) describe BMI, PA, SB, sleep duration, and GMS proficiency in South African preschool children and (2) identify relationships between variables. Methods: BMI, including z scores for height, weight, and BMI were determined. Seven-day PA, SB, and sleep were measured using accelerometry. GMS were assessed using the Test of Gross Motor Development (second edition). Associations were explored by comparing sleep, PA, SB, and GMS between BMI tertiles using the Kruskal–Wallis test. Results: Most (86%) children (n = 78, 50% boys) had a healthy BMI (15.7 [1.3] kg/m2). Children spent 560.5 (52.9) minutes per day in light- to vigorous-intensity PA and 90.9 (30.0) minutes per day in moderate- to vigorous-intensity PA; most (83%) met the current PA guideline. Nocturnal sleep duration was low (9.28 [0.80] h/d). Although daytime naps increased 24-hour sleep duration (10.17 [0.71] h/d), 38% were classified as short sleepers. Around half (54.9%) of participants complied with both PA and sleep guidelines. No associations between variables were found. Conclusion: Despite being lean, sufficiently active, and having adequate GMS, many children were short sleepers, highlighting a possible area for intervention.