USC (US) — American teens who eat their veggies and get lots of exercise are less likely to be obese. The opposite is true in China, particularly for teen boys from affluent families.
A new study, published in the American Journal of Health Behavior, is one of the first to examine how weight among Chinese adolescents relates to factors like sleep duration, physical activity, diet, and general demographics. Most of what researchers found runs counter to Western trends.
“Findings from this large cohort of data on Chinese youth suggest that weight-related correlates might play different roles in Chinese culture than they do in Western cultures,” says Ya-Wen Janice Hsu, a research assistant at University of Southern California.
“This suggests that influences on obesity are society-dependent, and assumptions based on Western societies may not be applicable to Chinese populations.”
As in the United States and Europe, teenagers in China who slept fewer hours and participated in more sedentary activities like watching television were more likely to be overweight. But that is where the similarities ended. Some of the major differences include:
- In China, parents with more education and more money were more likely to have obese children, whereas the same circumstances are related to a lower body mass index in Western countries.
- Chinese boys were more likely to be overweight than Chinese girls. In the United States, boys are just as likely as girls to be overweight.
- Younger children in China were more likely to be overweight than older children. The opposite is true for youth in Western societies.
- Chinese adolescents who reported frequent consumption of vegetables and infrequent intake of sweets and fast food were more likely to be overweight.
- Frequent participation in vigorous physical activity among Chinese youth was related with greater odds of being overweight.
For the study, 9,023 questionnaires were submitted by randomly selected middle school and high school students in seven of China’s most populated urban areas: Harbin and Shenyang in the northeast, Wuhan in central China, Chengdu and Kunming in the southwest, and Hangzhou and Qingdao in the coastal regions. Neighborhoods in all income levels were included.
The East-West inconsistencies may be explained in part by the fact that rice is a staple grain in the traditional Chinese diet and vegetables are often deep-fried and stir-fried (weight-related factors that were not measured by the study).
Industrialization and rapid economic growth have also affected Chinese diets and physical activity levels. Food consumption has increased and junk food has become more readily available. Physical activity has decreased as more people can afford cars, televisions and computers.
“The most interesting finding is overweight Chinese youth have higher social economic status,” Hsu says. “One potential explanation is that the unhealthy lifestyle changes, driven by the rapid shifts in Chinese economic climate, are choices available primarily to the wealthier population.
“As the Chinese economy continues to grow, it is crucial to track these paradoxical relationships, which may or may not “flip” to match relationships we now see in Western countries.”
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