TY - JOUR
T1 - Later sleep timing predicts accelerated summer weight gain among elementary school children
T2 - a prospective observational study
AU - Moreno, Jennette P.
AU - Razjouyan, Javad
AU - Lester, Houston
AU - Dadabhoy, Hafza
AU - Amirmazaheri, Mona
AU - Reesor-Oyer, Layton
AU - O’Connor, Teresia M.
AU - Hernandez, Daphne C.
AU - Najafi, Bijan
AU - Alfano, Candice A.
AU - Crowley, Stephanie J.
AU - Thompson, Debbe
AU - Baranowski, Tom
N1 - Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - Objectives and background: Social demands of the school-year and summer environment may affect children’s sleep patterns and circadian rhythms during these periods. The current study examined differences in children’s sleep and circadian-related behaviors during the school-year and summer and explored the association between sleep and circadian parameters and change in body mass index (BMI) during these time periods. Methods: This was a prospective observational study with 119 children ages 5 to 8 years with three sequential BMI assessments: early school-year (fall), late school-year (spring), and beginning of the following school-year in Houston, Texas, USA. Sleep midpoint, sleep duration, variability of sleep midpoint, physical activity, and light exposure were estimated using wrist-worn accelerometry during the school-year (fall) and summer. To examine the effect of sleep parameters, physical activity level, and light exposure on change in BMI, growth curve modeling was conducted controlling for age, race, sex, and chronotype. Results: Children’s sleep midpoint shifted later by an average of 1.5 h during summer compared to the school-year. After controlling for covariates, later sleep midpoints predicted larger increases in BMI during summer, (γ =.0004, p =.03), but not during the school-year. Sleep duration, sleep midpoint variability, physical activity levels, and sedentary behavior were not associated with change in BMI during the school-year or summer. Females tended to increase their BMI at a faster rate during summer compared to males, γ =.06, p =.049. Greater amounts of outdoor light exposure (γ = −.01, p =.02) predicted smaller increases in school-year BMI. Conclusions: Obesity prevention interventions may need to target different behaviors depending on whether children are in or out of school. Promotion of outdoor time during the school-year and earlier sleep times during the summer may be effective obesity prevention strategies during these respective times.
AB - Objectives and background: Social demands of the school-year and summer environment may affect children’s sleep patterns and circadian rhythms during these periods. The current study examined differences in children’s sleep and circadian-related behaviors during the school-year and summer and explored the association between sleep and circadian parameters and change in body mass index (BMI) during these time periods. Methods: This was a prospective observational study with 119 children ages 5 to 8 years with three sequential BMI assessments: early school-year (fall), late school-year (spring), and beginning of the following school-year in Houston, Texas, USA. Sleep midpoint, sleep duration, variability of sleep midpoint, physical activity, and light exposure were estimated using wrist-worn accelerometry during the school-year (fall) and summer. To examine the effect of sleep parameters, physical activity level, and light exposure on change in BMI, growth curve modeling was conducted controlling for age, race, sex, and chronotype. Results: Children’s sleep midpoint shifted later by an average of 1.5 h during summer compared to the school-year. After controlling for covariates, later sleep midpoints predicted larger increases in BMI during summer, (γ =.0004, p =.03), but not during the school-year. Sleep duration, sleep midpoint variability, physical activity levels, and sedentary behavior were not associated with change in BMI during the school-year or summer. Females tended to increase their BMI at a faster rate during summer compared to males, γ =.06, p =.049. Greater amounts of outdoor light exposure (γ = −.01, p =.02) predicted smaller increases in school-year BMI. Conclusions: Obesity prevention interventions may need to target different behaviors depending on whether children are in or out of school. Promotion of outdoor time during the school-year and earlier sleep times during the summer may be effective obesity prevention strategies during these respective times.
UR - http://www.scopus.com/inward/record.url?scp=85109951276&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85109951276&partnerID=8YFLogxK
U2 - 10.1186/s12966-021-01165-0
DO - 10.1186/s12966-021-01165-0
M3 - Article
C2 - 34247639
AN - SCOPUS:85109951276
SN - 1479-5868
VL - 18
JO - International Journal of Behavioral Nutrition and Physical Activity
JF - International Journal of Behavioral Nutrition and Physical Activity
IS - 1
M1 - 94
ER -