Measuring the Nutritional Transition in Madre de Dios Peru

Abstract

Obesity and hypertension are growing in low and middle income countries as food consumption patterns shift towards a western diet. Dietary intake and stage of nutritional transition can be ascertained through questionnaires and by measuring stable isotopes in keratinized tissues, such as hair. Stable isotope ratios of carbon (d13C) reflect relative consumption of C4 (sugar cane, maize) to C3 (yucca, rice, potatoes) plants; higher values are associated with a western diet. Stable isotope ratios of nitrogen (d15N) indicate the trophic level at which an individual is eating; lower values are associated with a western diet, reflecting less consumption of high trophic level fish or meats, and greater consumption of low trophic level proteins like chicken. To examine the link between nutritional transition and access to the western diet in the rapidly changing southern Amazon region of Madre de Dios, Peru, we conducted population-based household surveys with varied accessibility to the western diet (rural and urban households along both the Interoceanic Highway [IOH] and the Madre de Dios River) in 2014. Analysis of d13C and d15N measured in hair of one adult woman per household in these surveys (n=253) and the associations with food consumption patterns is reported. Women in riverine towns had statistically lower d13C values than their highway-living counterparts (p<0.001). Women living in urban communities had lower d15N values than their rural counterparts (p<0.01). These findings support our hypothesis that households along the highway are further in the nutritional transition than their riverine counterparts, and that urban households are further than rural ones. This was corroborated with the household food consumption data; urban households along the IOH had higher consumption of chicken, chips, and candies/sweets than rural households (p<0.05). Knowledge of these transitions inform programs targeted to reduce the impact of emerging chronic diseases.