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Updated: May 31, 2026

Assessment of Child Anthropometry in a Large Epidemiologic Study
Published on: February 2, 2017
Impact of infancy duration on adult size in 22 subsistence-based societies
Aneta Gawlik1, Robert S Walker, Ze'ev Hochberg
1Department of Pediatric Endocrinology and Diabetes, Medical University of Silesia, Katowice, Poland.
Aim:
Humans evolved to withstand harsh environments by adaptively decreasing their body size. Thus, adaptation to a hostile environment defers the infancy-childhood transition age (ICT), culminating in short stature. In natural-fertility human societies, this transition is associated with weaning from breastfeeding and the mother's new pregnancy. We therefore used the interbirth interval (IBI) as a surrogate for the ICT.
Methods:
We hypothesized that long IBI will be associated with smaller body size. The sample used is 22 subsistence-based societies of foragers, horticulturalists and pastorals from Africa, South America, Australia and Southeast Asia.
Results:
The IBI correlated negatively with the average adult bodyweight but not height. After correction for 'pubertal spurt takeoff' and 'weight at age 5', the IBI explains 81% of 'average adult weight' variability.
Conclusions:
This inter-population study confirms that body weight is adaptively smaller in hostile environments and suggests that the selected trait for this adaptation is the ICT age.
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