Plasticity in the growth of body segments in relation to height‐for‐age and maternal education in Guatemala

Abstract

Plasticity in the growth of body segments between populations has been researched in relation to migration, temporal change and high‐altitude studies. We study the within population variation in body segments, thus controlling for some of the environmental and genetic differences that could be at play in between populations studies. We test a version of the thrifty phenotype hypothesis, where the growth of head‐trunk and hand are prioritized due to their functional significance over height and leg growth. A total of 3913 Guatemalan, rural, semi‐urban and urban, Maya and Ladino children 6 to 15 years old were studied. Height, sitting height, leg length, and metacarpal length were studied in relation to three proxies for living conditions: height‐ and leg length‐for‐age, and maternal education. Estimation statistics and null hypothesis significance testing were used to analyze the data. Metatarsal length and sitting height values were higher than height and leg length respectively. Relative metacarpal length was conserved across height‐for‐age groups. Females were less affected than males for metacarpal length and sitting height, but more affected for leg length. Conclusion: Our results agree with the thrifty phenotype hypothesis, where metacarpal and sitting height growth would be prioritized over height and leg length due to greater functional significance.