The Price of Childhood Obesity

Walk into almost any school in America these days and there's ample evidence of the childhood obesity epidemic. Today about one in three children and adolescents is overweight, and the numbers are even higher in some minority groups. Research has already demonstrated a link between childhood obesity and a range of health problems, from type 2 diabetes to depression, acid reflux to asthma. Now two new studies, published in this week's issue of the New England Journal of Medicine, warn of a significant increase in the number of potentially fatal coronary heart disease cases in adults over the next few decades as a result of the prevalence of overweight kids today.

Using current childhood obesity figures, historical trend data and scientific models, researchers at the University of California, San Francisco, project in one study that by 2035 the prevalence of coronary heart disease in the United States will increase as much as 16 percent, with more than 100,000 excess cases of the disease attributable to the rise in obesity among kids. In the other study Danish researchers used health data from 276,835 Danes, as they grew from schoolchildren into adults, and found that those with a higher body mass index (a measure of body fat based on height and weight) in childhood had an increased risk of developing heart disease as adults. In an accompanying essay, Dr. David Ludwig, director of the Optimal Weight for Life Program at Children's Hospital Boston and an associate professor of pediatrics at Harvard Medical School, warns that without intervention the costs of childhood obesity may well become "catastrophic." He elaborated in an interview with NEWSWEEK's Jennifer Barrett. Excerpts:

NEWSWEEK: How significant are the findings in this study: that being overweight as a child increases the risk of developing coronary heart disease in adulthood?
Dr. David Ludwig: There's been a debate about the link between body weight [in childhood] with life expectancy in adulthood. But the researchers found that even small increases in body weight in childhood substantially increased the risk of coronary heart disease in adults. They followed about a quarter-million schoolchildren in Denmark as they grew up and entered middle age. This and other lines of investigation suggest that the entire debate about the impact of body weight on life expectancy will be overshadowed by the childhood obesity epidemic. Prevalence rates don't need to increase any further in kids for the public health impact to continue to mount in coming years.
 
You and your colleagues have predicted that pediatric obesity may shorten life expectancy in the United States by two to five years by the middle of this century—an effect equal to that of all cancers combined. How did you come to this conclusion?
We went through our own series of demographic models and put together that prediction. But we didn't actually go to a large population, as they did in Denmark. That is one of the unique aspects of this study. It is based on a survey of virtually all Danish schoolchildren over several decades. That's significant.
 
Besides a higher risk of heart disease, what other long-term health problems are you seeing in children who are obese?
Childhood obesity affects virtually every organ system in the body, and in ways that are different than obesity in adults.
 
How so?
It's not just because an obese child will carry the weight for much longer in life but because the weight is present when they are still growing and developing. Diseases like Blount's [in which the lower leg angles inward] occur because the child's bones are still forming and growing when they're carrying this weight. In a very obese child, maybe the excess weight permanently alters the neuropathways in the brain that regulate appetite control or the behavior of the fat cells. Or it causes permanent changes in the cardiovascular system that can affect the long-term risk of chronic diseases, independent of what their adult weight might be.
 
So the damage may already be done, even if they lose the weight later?
That's still speculative, but perhaps. There are several explanations for the Danish study. One is that being an overweight child translates into being an overweight adult. Another is that the behaviors that cause obesity in children—like a sedentary lifestyle and poor nutritional habits—track into adulthood, causing obesity at all ages. But another possibility is that being heavy in childhood causes irreversible or long-term changes in physiology that can alter the risk for chronic diseases [like heart disease or diabetes]. There's some reason to believe that this is true. Still, we have seen dramatic improvements in health when obese children lose weight—including the reversal of type 2 diabetes. If substantial weight loss occurs early in the development of type 2 diabetes, it can be cured in some cases. If type 2 remains, though, it generally becomes permanent.
 
We used to think of type 2 diabetes as a disease that affects adults. Is it a challenge to treat such diseases in kids?
In some senses childhood is the ideal time to influence lifestyle-related diseases, because their lifestyle habits haven't been ingrained as deeply. The problem is that kids are living in such an unhealthy environment wherever they go. Cities have been invaded by junk food, and opportunities for safe, physically active recreation continue to diminish. And the schools are often no refuge. In many cases parents bemoan the fact that rather than providing some assistance, the food offerings in schools actively undermine the parents' efforts in the home. But the few dollars that are saved by scrimping on school nutrition are going to be dwarfed by the many thousands of dollars that it will cost to care for obesity-related complications. We can pay a few more cents a day now or pay tens of thousands of dollars later for the treatment of diabetes or coronary bypass surgery.

You write that the first phase of the childhood obesity epidemic actually began in the early 1970s, as the average weight began progressively increasing among children around the country. Why didn't we pay more attention to it then?
Certainly in the last decade there has been a lot of attention given to obesity in general and to childhood obesity in particular. The public is very aware. Unfortunately, the national political leadership hasn't really gotten the message. Why is it that it is still OK for food manufacturers to spend billions of dollars convincing young kids to want to consume fast food, junk food and sugary drinks? This isn't a First Amendment issue. We have clearly established that the First Amendment doesn't protect tobacco manufacturers' advertising to kids. But many studies clearly link consumption of fast food and sugary drinks not only to poor nutritional quality but also to excessive weight gain.
 
How would you propose we address childhood obesity on a national level?
One way would be by regulating food ads aimed at kids. There should also be better funding for school lunch programs [to incorporate healthier options]. School cafeterias are all too often little more than a fast food court these days. Schools also need better funding so they don't have to decide between eliminating physical education versus having cutbacks in traditional academic subjects.
 
Do you think we should mandate physical education in schools?
I'd support legislation both requiring it and providing a funding mechanism for it. PE is just as important to long-term success as are academic subjects.

Why do you think we haven't put more taxpayer dollars toward ending this epidemic?
I really blame a lack of leadership in Washington in large part for the state of affairs. Many of the public health answers to the problem are presently available and straightforward, but they require some political sacrifice. In order to achieve that we need political leaders who can assemble a comprehensive vision for how to proceed and ask for short-term sacrifices from the special interests that are presently profiting from the status quo. There will be some special interests that will suffer financially from a comprehensive national strategy to attack the problem, but there is plenty of money to be made, too. A healthier population will be more economically productive, producing greater rewards for all of society, ultimately. But we cannot continue to let the considerations of short-term profits dictate the long-term public health in such a critically important area.

© 2007