Once obese as an infant, the relative risk of remaining obese appears to rise with increasing age. Thus, the early years of life have been posited as an important target period for obesity prevention. Widely viewed as a response to genetic, interpersonal, and environmental factors, obesity fundamentally reflects an imbalance between energy intake and expenditure. Self-regulation of energy intake aligned with physiologic need is essential to this balance. The process(es) by which infants begin to disassociate eating behavior from physiologic need is unclear, thus it is crucial to better understand predictors of individual differences in self-regulation of energy intake. It is well established that autonomic regulation may support infant behavioral regulation, suggesting that autonomic function may be a critical area to consider here. Moreover, self-regulation is strongly influenced by dyadic interaction quality during infancy, and findings reveal that more responsive interactions are associated with more effective autonomic regulation. A chronic mismatch between a caregiver's feeding behavior and the infant's state (feeding in the absence of hunger and/or feeding beyond fullness), is thought to contribute to obesity by undermining the infant's capacity to self-regulate intake; the current proposal will be the first to examine the effects on autonomic regulation. The investigators propose an intervention to enrich the capacity of mother-infant dyads to perform their respective interactive tasks. The investigators plan to teach mothers American Sign Language (ASL) signs indicative of hunger, thirst, and satiety, which they will in turn teach their preverbal infant. This training in ASL will be augmented with targeted information for mothers about infants' capacities to self-regulate energy intake in response to hunger and satiety and communicate those states with intention. Mothers also will be taught about expected development of infants' eating behaviors and nutritional requirements to support healthy growth.
Using a two-group randomized repeated measures design, this study aims to 1) evaluate the feasibility and acceptability of the intervention and study methods, including recruitment, enrollment, and data collection (self-report, anthropometrics, video observations, and respiratory sinus arrhythmia \[RSA\]) for infants and their mothers; 2) evaluate the initial impact of the intervention on observed feeding interactions, reported infant feeding behaviors and maternal feeding behaviors/beliefs, and infant nutritional intake and growth; and, 3) explore preliminary data on concordance between dyadic feeding interactions and autonomic regulation in both mothers and infants (RSA). In addition to a variety of self-report and anthropometric measures, this study will use integrated behavioral (video) and physiologic (RSA) measures to better understand feeding dynamics and their relationship with obesity risk. Understanding these processes is essential for developing appropriate preventions, or interventions, that will help reduce the prevalence of early childhood obesity and its extension into later childhood and beyond.
Study Phases:
Screening: screening for eligibility and obtaining consent
Study Treatment: study intervention/experimental treatment from baseline visit (\[Time 1 (T1)\]: age 4-9-months) monthly until 3-months post-baseline (\[Time 2 (T2)\]: age 7-12-months)
Follow-up: 6-months post-baseline (\[Time 3 (T3)\]: age 10-15-months)
