The Perceived Benefits of Height: Strength, Dominance, Social Concern, and Knowledge among Bolivian Native Amazonians

Research in industrial countries suggests that, with no other knowledge about a person, positive traits are attributed to taller people and correspondingly, that taller people have slightly better socioeconomic status (SES). However, research in some non-industrialized contexts has shown no correlation or even negative correlations between height and socioeconomic outcomes. It remains unclear whether positive traits remain attributed to taller people in such contexts. To address this question, here we report the results of a study in a foraging-farming society of native Amazonians in Bolivia (Tsimane’)–a group in which we have previously shown little association between height and socioeconomic outcomes. We showed 24 photographs of pairs of Tsimane’ women, men, boys, and girls to 40 women and 40 men >16 years of age. We presented four behavioral scenarios to each participant and asked them to point to the person in the photograph with greater strength, dominance, social concern, or knowledge. The pairs in the photographs were of the same sex and age, but one person was shorter. Tsimane’ women and men attributed greater strength, dominance, and knowledge to taller girls and boys, but they did not attribute most positive traits to taller adults, except for strength, and more social concern only when women assessed other women in the photographs. These results raise a puzzle: why would Tsimane’ attribute positive traits to tall children, but not tall adults? We propose three potential explanations: adults’ expectations about the more market integrated society in which their children will grow up, height as a signal of good child health, and children’s greater variation in the traits assessed corresponding to maturational stages

CONTRIBUTIONS OF NUTRITION VERSUS HYPOXIA TO GROWTH IN RURAL ANDEAN POPULATIONS

Previous research on diet and nutrition among peasant agriculturalists in the Andes has produced inconsistent results. As a consequence it has been difficult to determine the extent to which nutritional factors contribute to the slowed, prolonged growth and resultant small adult body size that is characteristic of these highland populations. The study examines patterns of diet and growth in the rural highland community of Nuñoa, Peru (elevation 4,000 m), and compares them to similar data collected on this community during the 1960s. Additional data from other locations in the Andes are then evaluated to discern critical determinants of growth variation. Analyses of the Nuñoan data indicate that nutritional factors have played a significant role in shaping statural growth at this location. Comparisons of other growth surveys indicate that Nuñoans remain among the smallest of all Andean populations. Additionally, urban/rural differences in growth are quite evident in the highlands, with the magnitude of this difference being greater than in other regions (i.e., coastal or jungle). It appears that income level and access to land strongly interact to direct and constrain food consumption patterns. The resulting differences in nutrition, in turn, appear to be strong predictors of growth variation. Consequently, studies that consider 1) dietary intake, 2) level of variability in diet, and 3) relative contributions of purchased and home-produced food to diet should contribute to furthering our understanding of growth variation in the Andes

Fat free mass explains the relationship between stunting and energy expenditure in urban Mexican Maya children

This article was accepted for publication in the Annals of Human Biology [© Informa Plc.] and the definitive version is available at: http://dx.doi.org/10.3109/03014460.2012.714403Background: Childhood stunting has been associated with an increased risk of obesity in adulthood, but the causes are unclear. This study hypothesizes that stunting significantly reduces both resting and activity energy expenditure. Aim: To assess and describe energy expenditure of low socio-economic Maya children and to determine whether stunting is independently related to energy expenditure after controlling for lean mass. Subjects and methods: Thirty-three urban Maya children, 17 boys, aged 7–9 years, living in Merida, Mexico, were measured for height, weight and bioelectrical impedance analysis (BIA). Body composition was estimated from BIA. Energy expenditure was measured for one week using the Actiheart (combined heart rate and accelerometer). Results: Stunting (height-for-age below the 5th percentile of NHANES III based references) affected 35% of these physically active children. Using multiple linear regression analysis, greater lean body mass predicted higher resting and activity energy expenditure. Stature was not a significant predictor of resting energy expenditure. A lower height-for-age z-score, but not stunting as a categorical variable, significantly predicted lower activity energy expenditure. Conclusion: The hypothesis that stunting reduces total energy expenditure (resting + active) in children is not supported. Rather, children with shorter stature and less lean body mass have lower total energy expenditure. Complex interactions between body size, body composition, and metabolic activity appear to elevate the risk for later life obesity in these Maya children