Exploring the Short-Sleep Obesity Association in Young Children

Abstract

There is strong and consistent epidemiological evidence that short sleep duration is associated with increased risk of obesity from early childhood. Childhood obesity and inadequate sleep have negative consequences for health and well-being, and the ability to target both of these public health concerns with a novel obesity intervention involving sleep extension is appealing; yet little is known about the mechanisms linking short sleep with obesity. In adults, hormonal mechanisms have been proposed; in young children, behavioural mechanisms and parenting are likely to be involved. Furthermore, the wider social and cultural determinants of short sleep and obesity should be incorporated into sleep-obesity research. This study aimed to explore some aspects of the sleep-obesity link in preschool children, using an exploratory design with a mixture of quantitative and qualitative methods, and applying an evolutionary medicine perspective.

Participants were 109 3-year-old children and their parents in Stockton-on-Tees. Children’s sleep (validated by actigraphy), food intake and activity over 4 days/5 nights were assessed by parental diary report, and body composition was measured. Parents’ attitudes were explored using semi-structured interviews.

Combined daytime and nighttime sleep duration was associated with central fat. Alternate parenting strategies were identified, based on regulation and consistency (routine-led), or child-governance and lack of regulation (routine-free). Building on the trends identified and the literature reviewed, I propose two hypotheses to explain the short sleep-obesity link in young children: the Behavioural Mechanisms Hypothesis (dietary and activity behaviours mediate or confound the association), and the Parental Confounding Hypothesis (parenting strategies, which vary with SES, impact on both children’s sleep duration and obesity risk). Parenting impacts children’s health by either limiting or facilitating discordance between children’s experiences in evolutionarily novel environments, and their biological make-up. I conclude that sleep-based obesity interventions should consider the wider context of children’s behaviours, particularly strategies of parenting.