Early Bedtime in Preschool Years Might Prevent Obesity in Adolescence

To determine whether putting preschoolers to bed early might reduce their risk for adolescent obesity, researchers assessed data from 977 U.S. children enrolled in a prospective cohort study at birth in 1991. Bedtime was reported by mothers when children were of preschool age, and body-mass index was assessed at age 15 years.

At a mean age of 4.7 years, 25% of children had bedtimes at or before 8 p.m., 50% between 8 and 9 p.m., and 25% after 9 p.m. After adjustment for maternal sensitivity (determined by observations of mother-child play interactions) and other factors, risk for adolescent obesity was reduced by half in children going to bed at or before 8 p.m., compared with those going to bed after 9 p.m. Nonwhite race/ethnicity, lower soc…