Instilling healthy eating and exercise habits in children may help prevent obesity later in life. But which kids most need such obesity-prevention efforts? A recent study by Jeremy Goldhaber-Fiebert and colleagues at Stanford's School of Medicine showed that this question is harder to answer than it seems. The study, published earlier this year in Medical Decision Making, found that targeting obesity prevention to small children who are overweight might not be effective. That's because a higher-than-normal weight at age 5 provides an accurate predictor of adult obesity only 50 percent of the time.

Goldhaber-Fiebert, an assistant professor of medicine and core faculty member of Stanford Health Policy, discusses the problem.

What does your paper tell us about the recent focus on childhood and adolescent obesity measurements?

Our study has two take-home messages. First, while childhood obesity is an important problem, solving childhood obesity alone will not solve future adult obesity problems. Second, addressing future adult obesity will require broader societal measures — not simply interventions focused on obese children.

It used to be that no one worried much if a small child was chubby; the doctor might say, "It's baby fat, he'll grow out of it." How has that changed?

In fact, our data show that many children still do "grow out of it." But our findings suggest that it is difficult to predict whether this will happen for a specific child. Consequently, efforts to help obese children must be connected to broader efforts to create healthy diets and habits for all children.

Childhood obesity is concerning both because it presents increased health risks for individuals while they are children and also because of the fear that it will translate into serious adult obesity-related health issues. Our analyses show that targeting children who are already obese is unlikely to be sufficient in addressing broader public health challenges of obesity in later childhood, adolescence and adulthood.

Are there other more promising screening criteria for chronic adult obesity instead of using a child's weight?

It really depends on the purpose of screening. Researchers have identified a variety of characteristics to predict a child's future obesity status — for example, easily observed measures like the weight of a child's parent as well as more complex measures such as their size at birth and the rapidity with which they subsequently grew and gained weight.

The challenge is to have a measure that both does not miss a substantial fraction of those who become obese later on and also does not falsely predict obesity for a large number of those who do not become obese as adults. The trade-off between these two types of errors depends on the seriousness of health implications of obesity and the costs of treating health conditions once they arise, as well as the health and economic costs of delivering preventive interventions to people who are identified as being at risk of becoming obese regardless of whether they become obese in the future.

What are some of the best potential approaches for reducing childhood obesity if the entire population is being targeted?

Given that many health-related habits are developed in childhood, efforts to create healthy eating and exercise habits in children would seem to be beneficial. But for most potential interventions, we lack evidence of their widespread effectiveness over a long period of time. Do reductions in obesity persist from childhood into adulthood? Do they lead to measurable improvements in health outcomes? We do not have answers to these key questions.

Food, beverage or sugar taxes and other manipulations to food prices or availability may be effective, but may also have unintended harms and certainly come at the cost of curtailing personal choice. Re-engineering the built environment or nudging people with various behavioral/economic mechanisms have garnered attention though, again, widely generalizable evidence on them is lacking. The problem deserves continued creativity and ongoing evaluation and testing.

Your paper focuses on which obese children will become obese adults, yet we are seeing a growing number of children experiencing type-2 diabetes and other negative health consequences of being overweight before they're even out of their teen years. Is adult obesity the best endpoint to focus on?

Obesity-related conditions of childhood clearly should not be ignored. What we are concerned about is the sense that people were conflating good care for children to deal with their shorter-term health needs (i.e., childhood obesity management to deal with childhood health issues) and the belief that such an approach might largely solve the broader adult obesity issues. Addressing childhood obesity is still important even if it does not fix adult obesity and its deleterious health consequences.

Erin Digitale is the pediatrics writer for Stanford School of Medicine's Office of Communication and Public Affairs.

China’s demographic landscape is rapidly changing, and the government has responded by launching ambitious social and health service reforms to meet the changing needs of the country’s 1.3 billion people. This week, officials approved a five-year plan to develop a comprehensive nationwide social security network.

Karen Eggleston, the Asia Health Policy Program (AHPP) director and a Stanford Health Policy fellow, discusses the success of China’s health care reforms—including its recently established universal health care system—and the long road still ahead.

Why is the overall health and wellbeing of China’s population important globally?

There are many reasons why the health of China’s citizens matters within a larger global context. On the most basic level, China represents almost 20 percent of humanity. But it is also a major player in the world economy and it depends on having a healthy workforce, especially now that its population is aging more. The government’s ability to meet the needs of its underserved citizens contributes to a more productive and stable China, and works towards closing the huge gaps we see in human wellbeing across the world.

China also potentially offers a model for other developing countries, such as India, that may want to figure out how to make universal health coverage work at a tenth of the income of most of the countries that have put it into place before.

What are some of the biggest changes in China’s health care system since 1949?

One of the most significant changes is that China has achieved very basic universal health insurance coverage in a relatively short period of time.  

Throughout the Mao period (1949–1978) there was a health care system linked to the centrally planned economy, which provided a basic level of coverage via government providers with a lot of regional variation. When economic reform came in 1980, large parts of the system—particularly financing for insurance—collapsed. The majority of China’s citizens were uninsured during the past few decades of very rapid social and economic development.

China’s overall population is changing quite dramatically, which means it has different health care needs, such as treating chronic disease and caring for an increasingly elderly population. The central government is trying to establish a system of accessible primary care—a concept that China’s barefoot doctors helped to pioneer but that fell into disarray—and health services that fit these new needs. 

How does China’s basic health care system work? Are there segments of the population still not receiving adequate coverage and care?

China has had a system where people can select their own doctors. Patients usually want to go to clinics attached to the highest-reputation hospitals, but of course, when you are not insured you almost always by default go to where you can afford the care. “It is difficult to see the doctor, and it is expensive” has been the lament of patients in China, so an explicit goal of the health care reforms has been to address this.

The term “universal coverage” has different definitions. China initially put in place a form of insurance that only covers 20 or 30 percent of medical costs for the previously uninsured population, especially in rural areas. Benefits have expanded, but remain limited. As with the previous system, disparities in coverage still exist across the population. China not only has a huge population with huge economic differences, but within that there is a large migrant worker population. It is a challenge to figure out how to cover these citizens and how to provide them with access to better care. The government is quite aware there are segments of the population not receiving equal coverage, and it continues to strive to resolve the issue.  

What are the greatest innovations in China’s health care system in recent years?

One of the most remarkable things China has achieved is really its new health insurance system. Even if the current coverage is not particularly generous it is nearly universal, and mechanisms are put in place each year to provide more generous coverage. China is also working on strengthening its primary care and population health services, infusing a huge sum of government money into these efforts. It is the only developing country of its per-capita income that has achieved such results so far.

Interestingly, a lot of people assume China achieved its universal coverage by mandate, while in fact the central government did so by subsidizing the cost for local governments and individuals. This reduces the burden, for example, on poorer rural governments and residents, and is one innovative way China is trying to eliminate the disparity in access to care.

Eggleston has recently published a working paper on China’s health care reforms since the Mao era on the AHPP website, as well as an article in the Milken Institute Review.

Gordon Liu, a Chinese government advisor on health care and the executive director of Peking University’s Health Economics and Management Institute, spoke at Stanford on May 29 on the future of China’s health care system.