Chronic insufficient sleep and diet quality: Contributors to childhood obesity

OBJECTIVE: To examine associations of chronic insufficient sleep with diet and whether diet explains the sleep-adiposity relationship. METHODS: In Project Viva, 1,046 parents reported children's sleep duration at 6 m and annually until midchildhood (7 y). The main exposure was a sleep curtailment score (6 m-7 y) ranging from 0 (maximal curtailment) to 13 (adequate sleep). In mid-childhood, parents reported children's diet; researchers measured height/weight. Multivariable linear regression assessed associations of sleep with diet (Youth Healthy Eating Index [YHEI]); sleep with BMI z-score adjusting for YHEI; and, secondarily, joint associations of sleep and YHEI with BMI. RESULTS: Mean (SD) sleep and YHEI scores were 10.21 (2.71) and 58.76 (10.37). Longer sleep duration was associated with higher YHEI in mid-childhood (0.59 points/unit sleep score; 95% CI: 0.32, 0.86). Although higher YHEI was associated with lower BMI z-score (-0.07 units/10-point increase; 95% CI: -0.13, -0.01), adjustment for YHEI did not attenuate sleep-BMI associations. Children with sleep and YHEI scores below the median (<11 and <60) had BMI z-scores 0.34 units higher (95% CI: 0.16, 0.51) than children with sleep and YHEI scores above the median. CONCLUSIONS: While parent-reported diet did not explain inverse associations of sleep with adiposity, both sufficient sleep and high-quality diets are important to obesity prevention.