Differences in body fractionation between indigenous and non-indigenous chilean schoolchildren

Introduction: The Mapuche is the most represented ethnic group (79.84%) among the eight native peoples of the Chilean indigenous population, however research examining body composition of aboriginal groups is scarce, including the Mapuche. Objective: To determine anthropometric and body fractionation differences between indigenous (Mapuche) and non-indigenous students in Chile. Methods: The sample included 151 indigenous students and 217 non-indigenous male students. Body fractionation was estimated using the protocol described by the International Society for the advancement of Kinanthropometry (ISAK). One-way analysis of variance (ANOVA) was used to estimate the statistical significance of differences between variables. Results: Mapuche children showed lower values for body weight (p < 0.01), height (p < 0.01) and all skinfolds, body perimeters and bone diameters evaluated compared to non-Mapuche, except for forearm circumference (p < 0.05) and transverse chest diameter (p < 0.05). Regarding body composition, the native students presented lower values of fat mass (p < 0.001), residual mass (p < 0.05) and epithelial mass (p < 0.05). However, they reach higher percentages for muscle mass (p < 0.01) and bone mass (p < 0.05) than non-indigenous students. Conclusions: Mapuche students present better scores for muscle and bone mass, while showing lower percentages of residual fat and epithelial mass with respect to non-Mapuche students from the same area of residence.