Childhood obesity is no longer just an American problem. Epidemiologist Youfa Wang seeks solutions to a global epidemic that is growing as rapidly as our kids.
Story by Nicole Peradotto
It’s a small world, after all?
Try telling that to Youfa Wang. The new chair of UB’s Department of Epidemiology and Environmental Health in the School of Public Health and Health Professions, Wang researches burgeoning BMIs around the globe. His findings, published in some of the scientific community’s most prestigious journals, illuminate an obesity crisis that is no longer contained within the United States, or even the West.
“In many countries, obesity is prevalent and increasing rapidly in adults and children,” says Wang, who has an MD and a PhD in nutritional epidemiology, and holds a joint appointment in UB’s School of Medicine and Biomedical Sciences. “There’s a high prevalence of it in Mexico, for example. It’s a problem in Brazil, the Netherlands, Australia, Canada…. The list goes on.”
Before joining UB last fall, Wang was an associate professor at Johns Hopkins University’s Bloomberg School of Public Health and School of Medicine, where he led a university-wide effort to secure a $16-million grant from the National Institutes of Health. The money went toward establishing a global center of excellence dedicated to better understanding the causes and prevention of childhood obesity. Wang, the center’s inaugural director, hopes to found a similar program at UB.
His seminal body of research in the field includes a cross-national comparison study on worldwide trends in childhood obesity that has been cited more than 1,500 times since its publication in 2006. With very few exceptions, he and his colleagues found that children had become heavier in the 67 countries they studied, including Wang’s native land of China.
“Most people are surprised to hear that overweight and obesity rates are actually increasing faster in China than in the United States,” he says. “The prevalence has gone up about a percentage point per year. About one-third of adults in China are overweight or obese. In major cities, about 20 to 30 percent of children are overweight or obese.”
Now, Wang is leading an ambitious study to explore the reasons behind this dramatic upswing. With a $2-million-plus NIH research grant, he and a team of international collaborators are exploring the interplay of biological, social, economic, environmental and policy factors affecting Chinese children’s eating habits, physical activity, weight and related health outcomes.
The study dovetails with Wang’s ongoing NIH-funded research on childhood obesity in the United States. Combined, this China-U.S. comparison research will help explain how factors ranging from individual biology to national food trade policies conspire to produce chunkier kids in both the world’s largest industrialized country and the world’s largest developing country.
Of even greater importance to concerned parents—including Wang, who has two sons under the age of 10—the work involves developing effective strategies for combating the global epidemic.
In 1985, China had a childhood overweight and obesity rate of only 3 percent. Just two decades later, it had escalated to roughly 10 percent in girls and 20 percent in boys.
That swift trajectory notwithstanding, it’s noteworthy that China’s youth, on the whole, are still slimmer than American kids, of whom one in three is overweight or obese. But China appears on pace to catch up. And in one key demographic—that of urban boys—Wang and his colleagues found that the Chinese actually outweigh their American counterparts.
“We recently saw the encouraging news that the obesity prevalence in the United States seems to have leveled off among very young children,” Wang says, citing data from the Centers for Disease Control and Prevention that showed that preschoolers’ obesity rates dropped between 2003 and 2012. “We’ve seen obesity rates begin to plateau in some European countries as well. However, in China they’re going in the opposite direction.”
What’s tipping the scales in the most populous nation on Earth?
In a PowerPoint presentation Wang created to help explain the obesity crisis in China, there’s a photo illustration of a preteen boy hefting a double cheeseburger to his mouth with a pair of chopsticks. A map and accompanying bar graph reveal the regional distribution of Kentucky Fried Chicken restaurants in China over two-and-a-half decades. In 1987, the first franchise set out its shingle; by 2010, 3,700 were in business, concentrated primarily on the urban East Coast, where obesity rates have skyrocketed.
“You would be amazed to see all the fast-food advertisements in China, in particular from American chains,” Wang says. “At least a few years ago, you would see them in elevators, on buildings, on billboards, on TV. Often they attempted to leave parents and children with the impression that these foods are healthy and desirable because they would provide you with adequate protein and were served in appealing restaurants. There are few regulations on this kind of thing because these restaurants produce tax revenue for the local governments. To officials, that’s a good thing because it grows the economy.”
Although fries and shakes have permeated the Asian dining scene, America’s high-fat export is just one of many culprits in the super-sizing of China’s kids. No one appreciates this more than Wang, whose research constantly reminds him of the seismic shifts that have taken place in his homeland since he was a boy.
Wang grew up in China during the 1970s and ’80s. He lived in the suburbs of Tianjin, China’s third-largest city. Like all Chinese citizens of that era, his family used government-issued coupons to obtain food, a rationing policy initiated in the 1950s to cope with scarcity in a country with a lot of mouths to feed but walled off from global trade.
"If you were a male, you could buy about 15 kilograms of grains for the month; for females, about 13 kilograms,” says Wang. “You had to plan well during the month so you wouldn’t run out of food at the end. Under these circumstances, it was very hard, if not impossible, to overconsume. Back then, the real problem was undernutrition.”
By the 1980s and ’90s, economic reforms in the country, combined with the opening up of global markets, made food more affordable and abundant while rendering the rationing system obsolete.
As the standard of living improved, many families—Wang’s included—began abandoning bicycles as a primary mode of transportation. In the capital of Beijing, for example, the number of cars on the road grew from 1 million to more than 5 million between 1997 and 2012.
What’s more, China’s one-child policy, mandated in the mid-1970s, unwittingly promoted sedentary behaviors among kids by shifting household duties onto older generations and according a privileged status to these singletons, dubbed “little emperors.”
“We call it the ‘1-2-4 syndrome’: The family has one child, two parents and four grandparents,” Wang says. “That means there are many resources to support just one child, so children have a lot of access to food and whatever else they want. At the same time, there’s not much work for kids to do around the house, which reduces their physical activity.”
Add to the equation a Chinese education system and social norms that emphasize and reward academic excellence while devaluing physical education. Then, consider that China’s youngsters, like their American peers, have an insatiable appetite for video games and high-tech gadgets. It’s a perfect storm for pediatric weight gain.
But what of the disparity in obesity rates between Chinese boys and girls? This gap doesn’t exist in the United States. Why are China’s boys twice as likely to be overweight as the girls?
“Girls—not only in China, but in Japan and South Korea as well—are heavily influenced by body image, and related peer and social influences,” says Wang, noting that they often take their image cues from Hollywood. “Their parents don’t want them to be heavy, either. But for boys, the standard is not the same. Parents aren’t that concerned about a heavy boy.” Indeed, he adds, his own mother still frets over his lanky frame every time he returns to China.
Wang notes an even more striking gender divide in tobacco use among China’s citizens. “Near to 60 percent of men smoke, but only about 3 percent of women do. That’s because smoking is viewed more favorably among men. It’s part of the male social and professional culture. It all comes back to cultural norms and acceptance.”
Whether in Beijing or Brooklyn, shifting these cultural norms is critical to combating many public health threats, childhood obesity included, Wang says.
“A lot of my work argues that obesity is not just a behavioral or biological problem. It’s not just an individual’s problem, or a family problem. Society plays a very important role in the equation. Society needs to create policies and programs that promote a healthier environment.”
Not surprisingly, one of the most effective places for healthy habits to gain traction is where kids spend the bulk of their days—in school.
Wang is an authority on the matter, having led federally funded research that resulted in an 835-page review of all published childhood obesity prevention studies—most of them school-based—that took place in high-income countries worldwide over the past three decades. Building upon that data, he and his colleagues recently reported in the journal Circulation that many of these programs, including those that didn’t reduce obesity in children, successfully reduced the children’s blood pressure.
A decade ago, Wang launched an NIH-funded school-based obesity-prevention program in Chicago. Working in four low-income public schools, his team took a series of steps to foster healthy lifestyles among the students. These included providing physical education equipment to the schools, training gym teachers, posting health-promotion posters and boosting the health curriculum. They hosted food tastings, coached the cafeteria workers to dole out portion sizes based on a child’s age, and even instructed them to cut up fruit to increase its eye appeal and reduce the likelihood that kids would dump it in the trash.
A few years ago, they initiated a similar study—this time, for middle-class students in the Chinese city of Nanjing.
Among children of different means and cultures, in schools at opposite ends of the planet, they observed similar results: The grade-schoolers in both sets of intervention schools had reduced body mass index compared with kids in the control schools.
“Education alone doesn’t work—or doesn’t work well,” argues Wang, emphasizing that his team’s programs succeeded because they approached the problem from many different angles.
As an example of a failed educational strategy, he points to the “Five-a-Day” campaign in the U.S., a government-led effort in the early ’90s to encourage Americans to up their consumption of fruits and vegetables.
“Considerable resources were used for that, and what was the result? Did people eat better? Did they eat more fruits and vegetables? Not really. What we need to do instead is modify people’s environment—to, in effect, change the default choices.”
With prompting from the federal government, that’s starting to happen in American schools.
As part of first lady Michelle Obama’s “Let’s Move” initiative, the U.S. Department of Agriculture in 2012 released rules to boost the nutritional quality of cafeteria meals, the first major revision of such standards in 15 years.
With new regulations requiring any food sold in public schools to meet calorie, fat, sugar and sodium limits, junk food and sugary beverages are being pulled from school vending machines. Earlier this year, the Obama administration announced a call for companies to phase out advertisements for such products on scoreboards and elsewhere on school grounds.
Beyond limiting children’s access to unhealthy food, these mandates have the added perk of drawing major media attention to the problem of childhood obesity, Wang notes. And when pudgy kids are put under the glare of the national spotlight, they’re hard to ignore.
“Childhood obesity has been in the news so much recently, and parents are paying attention,” says Wang, who has presented his research findings on the U.S. obesity epidemic and its related financial toll to lawmakers on Capitol Hill. “Parents are starting to make changes in the home, and I think that’s why we’ve seen a drop in the rates of obesity among preschoolers.”
As the fast-rising childhood obesity rates and the already high rates of cardiovascular disease and diabetes foreshadow a major public health crisis in China, the country can take cues from the United States’ example, which serves as both a narrative of hope, given the incremental improvements that have been made, and a cautionary tale of, literally, epic proportions. “China can look to the U.S. to see how bad the situation can get,” says Wang. “That is,” he adds, “how heavy kids can get.”
At this juncture, the obesity expert remains cautiously optimistic. China is providing universal health care coverage and investing more in public health. And while it does not have a first lady who has made it her mission to reduce childhood obesity rates, or major governmental support to advance such a cause, the country has implemented some initiatives to tackle obesity. For example, the Sunshine Sports Program, launched by China’s Ministry of Education in 2007, requires primary and middle school students to get at least one hour of physical exercise a day.
On the other hand, Wang is well aware of the challenges China faces—public health being one of many issues on the government’s plate. “The priority of most government officials in China is to develop the country, to build the economy and strengthen industry,” he concedes. “That’s the priority—not obesity.”
Nicole Peradotto is a writer and editor in UB’s School of Medicine and Biomedical Sciences.