Findings among children in the Amazon-Ecuador provide insight into the relative importance of diet versus energy consumption for increasing obesity.
According to a Baylor University study that provides insight into the global obesity epidemic, the consumption of market-acquired foods outside of the traditional diet – but not in the total amount of calories burned daily – is reliably related to indigenous Amazon children’s body fat .
“The importance of a poor diet versus low energy expenditure for the development of childhood obesity remains unclear,” said Samuel Urlacher, Ph.D., assistant professor of anthropology at Baylor University, CIFAR Azrieli Global Scholar and lead author of the study . ‘Using gold standard measures of energy consumption, we show that relatively lean, rural residence horticultural children in the Amazon spend about the same total number of calories each day as their much fatter counterparts abroad and, in particular, even the same number. calories every day as children living in the industrialized United States.
“Variation in things like normal physical activity and immune activity has no noticeable impact on the daily energy consumption of children in our sample,” he said.
The study – “Children’s daily energy expenditure does not decrease with market integration and is not related to obesity in Amazon” – was published in The Journal of Nutrition, the American flagship journal of the American Society for Nutrition, and is funded by the National Science Foundation.
“The initial outcome alone is exciting to confirm that we have found relative stability in the daily energy expenditure of children in different lifestyles and environments,” Urlacher said. “But our study goes further. It shows that Amazon kids who eat more high-calorie foods in the market – but not those who spend fewer calories each day – consistently have more body fat.
“Together, these findings support that the change in diet is likely to be the dominant factor influencing the global increase in childhood obesity, especially in the context of rapid urbanization and market integration in low- and middle-income countries,” he said.
According to the NCD Risk Factor Collaboration, the global rate of overweight / obesity among school-going children and adolescents has risen from 4% in 1975 to 18% from 2016. This reflects a major global health crisis. Children who are overweight / obese often remain in adulthood. They have shorter life expectancy and a greater lifetime risk of developing non-communicable diseases, including type 2 diabetes and heart disease.
“While the fastest increase in overweight and obesity in children is now in rural areas and in low- and middle-income countries, few previous studies have actually measured the energy consumption of children in these institutions to identify the cause of energy imbalance,” said Urlacher. .
To investigate the diet of school-age children and energy consumption during early market integration and transition to overweight / obesity, Urlacher and co-researchers * collected data among 43 rural and 34 urban Shuar children in the Amazon Ecuador. The Shuar has a large indigenous population of about 50,000. Children in the rural sample live in a geographically isolated region and rely mainly on a livelihood based on hunting, fishing, feeding and small-scale horticulture. In contrast, children in the sample for suburban studies live in a regional market center with access to roads, a hospital, shops, restaurants and other market facilities.
To measure variation in market integration among households, researchers collected information on things like income and access to running water. They also measured children’s physical activity using portable devices and immune activity by measuring biomarkers in minimally invasive finger-piercing blood samples. Most importantly, the researchers measured children’s daily energy expenditure using a stable isotope detection method ‘indicated twice’ and children’s rest consumption using respirometry – both participant-friendly, gold standard techniques.
The study found that:
- Children in urban areas are on average 65% more body fat than rural children, with more than a third of urban children being classified as overweight compared to rural children.
- Foreign urban children eat more than four times as many articles obtained through the market as children in rural areas.
- Children in urban and rural countries have similar levels of physical activity.
- Foreign urban children spend 108 calories less per day than rural children at rest. This is partly related to 16-47% lower levels of immune activity.
- Measures of market integration, immune activity and physical activity have no observable impact on the overall energy consumption of children, and children in the city and countryside spend about the same amount of calories.
- The difference in food consumption in the market, but not in the daily energy consumption, is related to children’s body fat.
The study is the first to measure children’s energy consumption across the entire market integration in a single population, along with diet, physical activity and immune activity. The finding that there is no effect of market integration on the measured daily energy consumption is consistent with previous reports among adults and infants, Urlacher said. It also supports an evolutionary model of energy constraint and award-winning awards among children in detail published by the researchers in their 2019 article in the journal. Scientific progress.
By measuring multiple aspects of the energy balance equation simultaneously, the researchers believe their findings provide compelling evidence for a likely primary role of altering dietary intake, rather than reducing daily energy expenditure, to promote the increase in childhood obesity.
“Our findings are consistent with an increasing body of research suggesting that poor diet is the major factor driving the development of obesity in children,” Urlacher said. “Exercise is absolutely still a critical part of this comparison and is essential to leading a healthy life, but the diet increasingly appears to be directly related to children’s fatness and long-term energy balance.”
The researchers plan to advance this work by collecting longitudinal data to determine the evolution of individuals’ lifelong development of obesity and cardiometabolic diseases. They also plan to collect more detailed dietary data and analyze a wider range of lifestyle and biological factors to identify causal pathways. The key point of these efforts is to determine how you can apply the best findings to improve children’s health in low- and middle-income countries.
“Childhood obesity is a complex issue that needs to be addressed at many different levels, ranging from biological to environmental, economic, social and political,” Urlacher said.
‘At the end of the day, everyone who works on this problem wants to do the same: to improve children’s lifelong health and well-being. We hope that this work can ultimately contribute to the effort, especially for the Shuar whose generosity and partnership made this research possible. ”
Reference: “Daily energy expenditure in childhood does not decrease with market integration and is not related to obesity in the Amazon” 18 January 2021, The Journal of Nutrition.
* Financial support for the study was provided by the National Science Foundation. Fellow researchers include the Department of Evolutionary Anthropology at Duke University, the College of Health Sciences at the Universidad San Francisco de Quito, the Department of Anthropology at the University of Oregon, the Department of Public Health Sciences at Loyola University, the Department of Anthropology at Northern Arizona University and the Department of Anthropology at Queens College.