Precursors to overnutrition: the effects of household market food expenditures on measures of body composition among Tsimane' adults in lowland Bolivia

Nutrition transitions are characterized by shifts in diet and activity levels that lead to changes in weight and body fatness over a relatively short time. Research has linked these nutritional shifts to socio-economic factors, including wealth and income. However, few studies have examined household spending patterns on market foods among subsistence populations, which may reveal food access, choice, and indicate household nutritional environment. This paper examines the relation between household monetary expenditures on "market" foods and measures of body composition among Tsimane', a forager-horticulturalist indigenous group in the Bolivian Amazon. Economic and anthropometric surveys were conducted for adults (n = 1199) 16 years or older in 563 households in 40 Tsimane' villages in 2008. Results indicate that overweight status (19% of men and 24% of women) is more common than obesity (1% of men and 4% of women). Sixty-one percent (61%) of households reported purchasing market foods during the previous week. Multiple linear and logistic regressions suggest that men living in households in the top third of monetary expenditures on market foods had significantly higher BMI (0.69 kg/m(2); p = 0.027), weight (1.80 kg; p = 0.048), percent body fat (1.06%; p = 0.025), and probability of being overweight/obese (Odds ratio = 1.83; p = 0.042) than men in households that reported not spending money on market foods in the previous week. We discuss the possibility that the division of labor may help explain the differences between men and women in this sample. This research suggests household expenditures on market foods may mediate the relation between wealth and body composition.