Influences of human milk metabolic hormone transfer and breastfeeding practices on early infant growth and body composition in Samoa (WGF - Dissertation Fieldwork Grant)

This resource is an application for a Dissertation Fieldwork Grant from the Wenner-Gren Foundation. With the rates of obesity continuing to rise worldwide, this project presents the opportunity to understand early-life metabolic development, growth patterns, and the prevalence of obesity in human populations. Current research supports the theory that maternal/infant energy transfer through human milk influences early nutritional development of the infant and begins metabolic programming that can influence later eating patterns. As a result, breastfeeding has been hypothesized to be protective against obesity later in life. However, despite their exceptionally high breastfeeding initiation rates – 94% initiation with 55% continuation to 5-months exclusively – Samoan communities continue to exhibit high levels of obesity. We will investigate the relationship between metabolic hormones in human milk, maternal body composition, and infant satiety to explore mechanisms of satiety development and implication for early infant growth. Through study of populations who share different ecologies and lifestyles from the majority of Western populations, we question the implication that the association of adiposity with metabolic hormone concentration is shared by all humans. The results will be used to advance our understanding of the evolutionary significance of breastfeeding patterns, providing a deeper understanding of the developmental programming of satiety and implications for growth trajectories during the critical period of infancy.