The timing and quality of sleep was associated with dietary quality and anthropometry in toddlers born preterm.

Aim: The aim of the study was to examine prospective associations of sleep characteristics (duration, timing, quality) with dietary and anthropometric measures among toddlers born preterm (<35 weeks).

Methods: Children participated in the Omega Tots trial at 10-17 months' corrected age (Ohio, USA; 26 April 2012 to 6 April 2017). Caregivers reported toddlers' sleep at baseline using the Brief Infant Sleep Questionnaire. After 180 days, caregivers reported toddlers' past month diet in a food frequency questionnaire, and anthropometry was measured using standardised protocols. The toddler diet quality index (TDQI: higher scores indicating better quality), and weight-for-length, triceps skinfold and subscapular skinfold z-scores were calculated. Linear and logistic regression assessed adjusted associations with dietary and anthropometric outcomes at 180-day follow-up (n = 284), and linear mixed models assessed changes in anthropometry.

Results: Daytime sleep was associated with lower TDQI (β per hour = -1.62 (95% CI: -2.71, -0.52)) whereas night-time sleep was associated with higher TDQI (β  = 1.01 (95% CI: 0.16, 1.85)). Night-time awakenings and caregiver-reported sleep problems were also associated with lower TDQI. Night awakening duration and sleep-onset latency were associated with higher triceps skinfold z-score.

Conclusion: Daytime and night-time caregiver-reported sleep showed opposite associations with diet quality, suggesting that sleep timing may be important.