The experience of Maya children may be instructive for the rest of the population since it allows scientists to measure the consequences of different environments on a relatively homogenous population.
"While greater average height and longer legs may indicate better health, an alarming number of the Maya-American children exhibit weight problems: nearly half are overweight and 42 percent are obese," according to Barry Bogin, professor of anthropology at the UM-Dearborn.
"And this childhood overweight is likely to lead to health problems and significant costs when the kids are adults," according to Bogin. "The long-term health problems include diabetes and heart disease, but overweight children are also more likely to perform poorly in school and have poor self image, leading to lower social and economic status later in life."
In comparison, about 14 percent of white and black children in the United States are overweight or obese, "so the American Maya rates are very high," Bogin said. "Overweight is common in other immigrant groups, especially from Latin America and Asia, so the Maya are a representative case for a lot of other people."
Bogin and UM-Dearborn colleagues Patricia Smith and Maria Ines Varela Silva presented findings on "Patterns of Emerging Obesity among Maya in Guatemala and in the United States" at the annual meeting of the American Association for the Advancement of Science in Boston Feb. 16. Bogin spoke as part of a symposium on Biocultural Insights on the Emerging Worldwide Epidemic of Obesity.
The UM-Dearborn researchers compared measurements of thousands of Maya children in Guatemala with hundreds of Maya children in communities in Los Angeles and central Florida since 1992.
In estimates of fatness using body mass index (BMI), a widely accepted measure of weight for height, Bogin's team found that Maya children in Guatemala have a BMI of 16.2 while Maya in the United States average 20.2.
The BMI figures actually may understate the disparity between Maya in Guatemala and those in the United States, Bogin says, because the Maya in Guatemala have very short legs in proportion to total stature. "This body shape may distort BMI values and overestimate fatness among that population," he said.
Bogin used socioeconomic data to explore the factors that might lead to weight problems among Maya children in the United States. "Children in our study who report watching television or playing computer games as favorite leisure activities face of higher chance of overweight," he said.
"Other studies in the United States have shown a connection between television viewing and weight problems, so our study is not unusual, but we do show this lifestyle affects the immigrant kids more than the children of long-term residents," Bogin said.
The degree of "American acculturation" may also have an impact, Bogin said. "Children whose parents answered the questionnaire in Spanish rather than English face a lower chance of obesity," he said.