Explosion in childhood obesity in China ‘worst ever’, expert says of new study findings
29-year study finds childhood obesity up 17-fold among boys and 11-fold among girls in rural Shandong; Western lifestyle blamed as doctor calls for ‘catastrophe committee’ to stem rise
Thirty years ago, for every 100 children and adolescents you came across in China, you’d be hard pressed to find even one who was obese. That situation has drastically changed: in 2014, about one in six boys and one in 11 girls were obese, a new study shows.
Researchers say China is paying the price of adopting a Western lifestyle and the findings are a wake-up call for Chinese policymakers to take steps to stem the trend. The 29-year study, published on April 26 in the European Journal of Preventive Cardiology, involved nearly 28,000 rural students from Shandong province.
“This is extremely worrying,” says Professor Joep Perk, cardiovascular prevention spokesman for the European Society of Cardiology. “It is the worst explosion of childhood and adolescent obesity that I have ever seen. The study is large and well run, and cannot be ignored. China is set for an escalation of cardiovascular disease and diabetes, and the popularity of the Western lifestyle will cost lives.”
Dr Zhang Yingxiu, leader of the investigation team at the Shandong Centre for Disease Control and Prevention, Shandong University Institute of Preventive Medicine in Jinan, Shandong, says: “China is a large agricultural country and our findings have huge implications for the entire nation. The rises in overweight and obesity coincide with increasing incomes in rural households and we expect this trend to continue in the coming decades in Shandong province and other regions of China.”
Data for the study was obtained from six national surveys of schoolchildren carried out by the Department of Education in Shandong between 1985 and 2014. A total of 27,840 rural students aged seven to 18 years had their height and weight measured.
Body mass index (BMI) was calculated by taking weight in kilograms divided by the square of height in metres (kg/m²). Overweight and obesity were defined using cut-off points recommended by the Working Group on Obesity in China, the International Obesity Task Force and the World Health Organisation.
The prevalence of overweight and obesity in boys increased from 0.74 per cent and 0.03 per cent in 1985 to 16.4 per cent and 17.2 per cent in 2014, and in girls increased from 1.5 per cent and 0.12 per cent in 1985 to 13.9 per cent and 9.1 per cent in 2014, respectively.
Rising childhood obesity is not unique to China. In the United States, a new study published online in the journal Obesity shows that overweight and obesity among children aged two to 19 has been continually increasing since 1999, reaching 33.4 per cent in 2014. In particular, the prevalence of severe obesity – correlated to an adult body mass index of 35 or higher – has seen the sharpest increase.
In Hong Kong, the rate of overweight and obesity among school children is lower, according to statistics from the Centre for Health Protection. Among primary school students, the combined rate of overweight and obesity rose from 16.1 per cent in 1995/96 to 22.2 per cent in 2008/09 and fell to 20 per cent in 2013/14. For secondary school students, the corresponding rate increased from 13.2 per cent in 1996/97 to 19.5 per cent in 2013/14.
China’s enormous population and diverse regions compound the situation.
“Rural areas of China have been largely ignored in strategies to reduce childhood obesity,” says Zhang.
“This is a wake-up call for policymakers that rural China should not be neglected in obesity interventions. We need to educate children on healthy eating and physical activity, and monitor their weight to check if these efforts are making a difference.”
The authors speculate that boys are fatter than girls because they are given preferential treatment. The Chinese 2005 National Youth Risk Behaviour Surveillance reported that 4.3 per cent of boys and 2.7 per cent of girls frequently had soft drinks, while 12.7 per cent of boys and 4.3 per cent of girls spent more than two hours per day playing computer games.
Zhang says: “Traditionally the societal preference, particularly in rural areas, has been for sons. That could result in boys enjoying more of the family’s resources. In addition, boys may prefer to have a larger body size than girls.”
“Computer games themselves are not the issue,” adds Perk. “The problem is that kids sit there with a two-litre bottle of fizzy drink. To burn those calories they would need to walk 46 kilometres but they don’t.”
The prevalence of overweight and obesity is rising faster in children (seven to 12 years) than adolescents (13 to 18 years), which the authors say could be because teenagers are more concerned about their appearance. “Adolescents generally pay more attention to their body shape and do more exercise than children,” says Zhang.
Rapid social and economic change in the past 30 years in China have been accompanied by nutritional changes, Zhang says. “In China today, people eat more and are less physically active than they were in the past. The traditional Chinese diet has shifted towards one that is high in fat and calories and low in fibre.”
Perk says: “This calls for a catastrophe committee in China to stop the alarming rise in childhood and adolescent obesity. They need to return to their former nutritional habits instead of eating junk food. Parents must take some responsibility and point their children in the direction of healthier choices.”