By Alison Lobron
Starting next year, Massachusetts schools will calculate students’ Body Mass Index, a small shift in procedure that has attracted considerable attention. The shift is small because schools already measure students’ height and weight, and BMI is merely a ratio of one to the other. But that little piece of math will allow parents to compare their child’s physique to that of others, and get a sense of whether their kid is part of what researchers call an “obesity epidemic.” According to a Centers for Disease Control report, obesity rates among elementary schoolchildren have quadrupled since the early 1970s.
Dr. David Ludwig, director of the Optimal Weight for Life program at Children’s Hospital in Boston, has been on the front lines of the epidemic since the mid-1990s. His clinic sees more than 500 new overweight young people each year. Even as Ludwig provides individualized care, he thinks reversing the increase in obesity rates requires systematic, societal change: more walking and biking opportunities in communities, less reliance on cars, reduced junk-food advertising, and easier, cheaper access to nutritious foods, in and outside of schools. Tools like BMI report cards will only be helpful if they happen in conjunction with other changes, he thinks. I spoke with Ludwig by phone about his research.
How did you come to focus on treating overweight children?
I was doing research on the molecular and genetic causes of obesity. While the work was very interesting, I came to feel that identifying a new gene that affects body weight was unlikely to have a major impact anytime soon on the obesity epidemic. The epidemic has developed much too quickly to be explained by genetic reasons. We don’t have to look hard to see the myriad environmental reasons at play.
We hear a lot about how fat Americans are. Is this a uniquely American problem?
By no means. America may be leading the way, but the rest of the world, including developing nations, are following rapidly in our footsteps. The obesity epidemic began earlier, in the ‘70s, in the US, but most other countries have shown the same demographic changes, just delayed by a decade or two.
Many of the common culprits for childhood obesity, like TV-watching, soda, and sidewalk-less suburbs have been around for well over 50 years. Why has there been such a big change in the last 20 or 30?
Coke in the 1950s was served in 6-ounce sizes. Now, it’s 24 ounces and beyond. And that characterizes much of the processed food supply. In part because of our agricultural policy, we have cheap, poor-quality food invading the diet in concentrations never seen before. It’s daily fare for many, if not most, children. Link that to severe cutbacks in physical activity among children, both in school and after school, that limit the opportunity to get outdoors and be kids. Combine this all with pressures on the family, and parents having less time to supervise kids, and the impact of stress itself. Stress can actually alter your metabolism.
Your suggestions are quite far-reaching. They involve changes in food production, education, transportation, and land use. Given the complexity, if you could ask the state to take two actions, what would they be?
Better funding for nutrition education and physical activity in schools. And, as best as possible on a state level, limit the marketing of junk food to children. I don’t know how much control the state has in TV advertising, but they presumably do have some over billboards.
How much do little kids make their own food decisions based on ads?
The food industry wouldn’t spend billions advertising in Saturday morning cartoons if it weren’t effective in altering behaviors. In addition, they create what’s called the nag factor. Maybe the child doesn’t buy the supersize Twinkie, but they nag the parents for it. And the parents eventually give in. It’s insidiously undermining parental responsibility by the very folks who argue the obesity epidemic is an issue of personal responsibility. I don’t want to put all the blame on the food industry. It’s not monolithic. There are more and less responsible voices that are vying for control in the industry. What we need are tougher regulations to level the playing field so the company that’s trying to market responsibly isn’t undermined by the one who isn’t. It’s like political advertising.
How much effect does telling people that they (or their kids) are too fat have on their weight? And what do you think of the BMI going home to parents?
They are a good screening tool for children. I’m concerned about their inappropriate use — namely, notifying parents that their children may be obese and, at the same time, allowing policies and practices in schools that are promoting the problem. It’s the ultimate irony: telling people they have a problem and undermining their efforts to do anything with very poor quality school lunch and inadequate opportunities for physical education. BMI report cards as part of a comprehensive obesity initiative could be helpful. People need to know if their child is at risk. In and of itself, it can cause more harm than good.