"Child obesity is becoming a public health problem worldwide, but the prevalence of obesity varies remarkably across countries with different socioeconomic development levels," said Dr. Youfa Wang, who conducted the study through UNC's Carolina Population Center and School of Public Health. "Different socioeconomic groups are at different risks, and the relationship between obesity and socioeconomic status varies across countries."
Wang completed a doctorate in nutritional epidemiology at UNC last spring and recently joined the University of Illinois at Chicago as assistant professor of human nutrition. A report on his findings appears in the October issue of the International Journal of Epidemiology, which is being published Oct. 24.
In the United States, he found the prevalence of obesity and overweight in children to be 11.1 percent and 14.3 percent, respectively. In Russia, rates were 6 percent and 10 percent, respectively. In China, the percentages were 3.6 and 3.4.
"Chinese children from more affluent families were more likely to be obese, but in the United States, children from poorer families were at higher risk," Wang said. "In Russia, both higher- and lower-income families' children were likely to be obese when compared with those from medium-income families. Obesity was more prevalent in urban areas of China and in rural areas of Russia."
Excessive body fat, especially in children, concerns health professionals since it promotes heart disease and diabetes, he said.
For the first time, the researcher used comparable data for children ages 6 to 18 from nationwide health surveys conducted in the United States from 1988 to 1994, in China in 1993 and in Russia in 1992. Previous studies could not tap such data, and so accurate comparisons could not be made from one country to another.
He selected the three nations since they are among the world's most populous, occupy three continents and represent three different levels of economic development. Together they account for about a quarter of the world population.
"Although the problem of childhood obesity is much more serious in the United States than in Russia and China, we did observe in those countries a very remarkable increase, especially among younger children, those in urban areas and those in high socioeconomic groups," Wang said. Generally, excess body weight in developing countries reflects enough income to buy more food, particularly high-fat and high energy-density foods such as meats, he said. In wealthy countries like the United States, many poorer people still can overeat but are unaware of or ignore the health risks.
Wang's study was prompted by a recent World Health Organization determination that an examination of obesity in children and adolescents across the world based on a standardized obesity classification system was urgently needed.
The new research confirms the suspected global epidemic of childhood obesity, he said.
Note: Wang can be reached at 312-355-3382 or firstname.lastname@example.org
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