Can We Promote Responsive Bottle-Feeding Practices By Simply Giving Mothers Different Bottles?

Introduction:Rapid weight gain during the first year of life is a strong predictor of later obesity. Mounting evidence illustrates that bottle-fed infants (whether fed formula or expressed breast milk) are at significantly greater risk for rapid weight gain. It is hypothesized that bottle-feeding mothers develop more controlling feeding practices than breastfeeding mothers due to their ability to feed in response to the amount of liquid in conventional, clear bottles, instead of in response to infant satiation cues, leading to overfeeding and excess weight gain. Although promotion of breastfeeding is ideal, the majority of mothers use bottles for infant feeding and a paucity of research has focused on understanding how to improve bottle-feeding mothers’ responsiveness to infant satiation cues. Thus, the objective of this study was to explore a novel, pragmatic approach to promote healthy bottle-feeding: an opaque, weighted sleeve that fits over any bottle and removes a mother’s ability to assess the amount her infant consumes during each feeding.

Methods: Bottle-feeding dyads (N=66) feeding either formula (n=30) or expressed breast milk (n=36) visited our laboratory on two separate days for feeding observations. Mothers were video-recorded while feeding their infants from a clear bottle on one day and an opaque on the other; bottle-order was counterbalanced. Maternal sensitivity and responsiveness to infant cues was objectively assessed using the Nursing Child Assessment Parent-Child Interaction Feeding Scale. Infant intake was assessed by weighing the bottle before and after the feeding.

Results: Across both feeding observations, mothers who fed their infants expressed breast milk exhibited significantly greater sensitivity (p<.001) and responsiveness (p=.001) to their infants’ cues compared to mothers who fed their infants formula. Additionally, infants consuming expressed breast milk consumed significantly less compared to infants consuming formula (p=.002). No overall effect of bottle-type on mothers’ sensitivity and responsiveness or infant intake was seen. Milk type moderated the impact of bottle-type on mothers’ responsiveness (p=.02) and infant intake (p<.001). Specifically, no effect of bottle-type on mothers’ responsiveness and infant intake was seen for mothers who fed their infants expressed breast milk. In contrast, mothers who fed their infants formula showed greater responsiveness (p=.02) and fed their infants less formula (p=.01) when feeding from an opaque compared to a clear bottle.

Conclusions: This study highlights a simple yet effective intervention for improving the bottle-feeding practices of formula-feeding mothers in the short-term. Implications for future research and family-based interventions will be discussed.