Variation in consumption of market-acquired foods outside of the traditional diet -- but not in total calories burned daily -- is reliably related to indigenous Amazonian children's body fat, according to a Baylor University study.
The study offers insight into the global obesity epidemic. "Using gold-standard measures of energy expenditure, we show that relatively lean, rural forager-horticulturalist children in the Amazon spend approximately the same total number of calories each day as their much fatter peri-urban counterparts and, notably, even the same number of calories each day as children living in the industrialized United States," said Samuel Urlacher, assistant professor of anthropology at Baylor University, and lead author of the study.
"Variation in things like habitual physical activity and immune activity have no detectable impact on children's daily energy expenditure in our sample," he said in a report published by the Medical News Today website.
The study "Childhood Daily Energy Expenditure Does Not Decrease with Market Integration and is not Related to Adiposity in Amazonia" found that:
1. Peri-urban children eat more than four times as many market-acquired items as rural children.
2. Peri-urban and rural children have similar levels of physical activity.
3. Peri-urban children spend 108 calories per day less than rural children while at rest. This is related in part to 16-47 percent lower levels of immune activity.
4. Measures of market integration, immune activity and physical activity have no detectable impact on children's overall energy expenditure, with peri-urban and rural children spending roughly the same number of calories.
5. Variation in consumption of market foods, but not in daily energy expenditure, is related to children's body fat.