Relationship of Feeding Practices with Sleep Duration on Infant Weight at 12 Months

Background

Infant feeding practices and sleep duration are closely linked with weight gain. Evaluation of factors that impact infant growth patterns may serve as a predictor for obesity later in life. Longitudinal studies in infants have frequently reported an association between feeding practices/styles and adiposity; however, the influence of sleep duration and diet on adiposity has limited assessment.

Objectives

To examine the longitudinal associations between feeding practices and sleep duration on infant weight at 12 months.

Methods

A total of 140 mother-infant dyads were recruited from Special Supplemental Nutrition Program for Women, Infants, and Children clinics in a southeast Texas county. Daily sleep duration (nocturnal plus diurnal), feeding practices (breastfeeding, bottle feeding, combination), and age (months) at introduction to solid foods were parent-reported at three time points (1, 6, & 12 mos.) using the Brief Infant Sleep Questionnaire, Feeding Observation questionnaire, and Growth and Nutrition survey, respectively. The outcome variable was infant weight at 12 mos. and predictor variables included, total sleep duration (1, 6, 12 mos.), feeding practices (1, 6, & 12 mos.), breastfeeding and bottle feeding duration, and age at introduction to solid foods. Data were analyzed using mixed linear models (SPSS 23) with subject as a random effect and time as a repeated variable for correlated residuals. Significance was defined as p<0.05.

Results

Breastfeeding decreased over time with 24.3% (34) of infants breastfed at 1 month, 17.1% (24) at 6 months, and 10.7% (15) at 12 months. Total, average sleep duration decreased with mothers reporting 16.26±2.77, 13.08±2.12 and 12.88±1.81 hours of sleep at 1, 6, and 12 months, respectively. The average infant weight at 12 months was 10.39±2.30 kg. By 12 months, average breastfeeding duration was 34±16 weeks and average bottle feeding duration was 46±10 weeks, with 52% (65) of infants being bottle fed. The main effects of continuous sleep duration (P=0.070) and categorical sleep duration (P=0.066) were trending toward statistical significance. Interactions of feeding practices with continuous (P=0.629) and categorical (P=0.116) sleep duration were not significant. Main effects of feeding practice, age at introduction to solid foods, breastfeeding duration and bottle feeding duration were not significant. There was no interaction between sleep duration variables and age at introduction to solid foods, breastfeeding duration or bottle feeding duration.

Conclusion

In this study neither breastfeeding nor sleep duration were associated with weight gain during infancy. While other studies are suggestive of relations between these variables, lack of significant findings may be the result of greater variability in reported values. Further investigation is warranted to understand infant behaviors and increased risk for adiposity during this intense and critical period of growth and development.