Menarcheal timing is accelerated by favorable nutrition but unrelated to developmental cues of mortality or familial instability

Menarcheal timing is accelerated by favorable nutrition but unrelated to developmental cues of mortality or familial instability in Cebu, Philippines. Moira A. Kyweluka et al. Evolution and Human Behavior, https://doi.org/10.1016/j.evolhumbehav.2017.10.002

Abstract: Understanding the determinants of pubertal timing, particularly menarche in girls, is an important area of investigation owing to the many health, psychosocial, and demographic outcomes related to reproductive maturation. Traditional explanations emphasized the role of favorable nutrition in maturational acceleration. More recently, work has documented early maturity in relation to markers of familial and environmental instability (e.g. paternal absence), which are hypothesized to serve as cues triggering adaptive adjustment of life history scheduling. While these studies hint at an ability of human females to accelerate maturity in stressful environments, most have focused on populations characterized by energetic excess. The present study investigates the role of developmental nutrition alongside cues of environmental risk and instability (maternal absence, paternal absence, and sibling death) as predictors of menarcheal age in a well-characterized birth cohort born in 1983 in metropolitan Cebu, the Philippines. In this sample, which was marked by a near-absence of childhood overweight and obesity, we find that menarcheal age is not predicted by cues of risk and instability measured at birth, during childhood and early adolescence, but that infancy weight gain and measures of favorable childhood nutrition are strong predictors of maturational acceleration. These findings contrast with studies of populations in which psychosocial stress and instability co-occur with excess weight. The present findings suggest that infancy and childhood nutrition may exert greater influence on age at menarche than psychosocial cues in environments characterized by marginal nutrition, and that puberty is often delayed, rather than accelerated, in the context of stressful environments.

Keywords: Life history theory; Puberty; Reproductive timing; Human growth; Fertility milestones