hitney Houston once sang, “I believe the children are our future.” We agree. But we’re worried that many kids won’t reach a healthy future because they aren’t active enough today and won’t be as they grow older. Based on results from a model we just published in the journal Health Affairs, too little physical activity among children now and later will translate into heart attacks, diabetes, cancer, and billions of dollars of avoidable health care costs.
Fewer than one-third of children are “active to a healthy level.” The Sports and Fitness Industry Association defines that as 25 minutes of high-calorie-burning physical activity three times a week. Twenty-five minutes isn’t that long. It’s less than an episode of “Sesame Street” and slightly longer than the time it takes to eat a meal or snack. And the percentage of children who meet this goal has been falling.
Physical activity is a key contributor to current and future health. It helps kids maintain a healthy weight and also improves bone and muscle strength, circulation, mental health, and many other aspects of health. Being overweight or obese can lead to a variety of chronic diseases, such as diabetes, cardiovascular disease, and cancer. It’s not the only thing that helps kids stay at a healthy weight — food and drink, sleep, stress, and medications can also affect weight — but it plays a big role.
Our team at the Global Obesity Prevention Center at Johns Hopkins University, in collaboration with colleagues at the Pittsburgh Supercomputing Center at Carnegie Mellon University, wanted to know what would happen if our country’s children exercised more. We developed a computer simulation called Virtual Population for Obesity Prevention, or VPOP. It serves as a virtual laboratory that lets us test the effects of different changes on all Americans or on segments of the population.
In our model, every virtual child has a height and weight, age, household location, and other characteristics that match the distribution of real children in the United States. Each one also has a starting body mass index, which is a measure of weight for height. Every simulated day, each virtual child consumes specified amounts of food and beverages based on what American children are really eating these days — which isn’t always good. For every simulated day, each virtual child also has a probability of engaging in different amounts of physical activity, again based on data. The model converts daily calories in and out and amount of physical activity to changes in weight.
The simulation proceeds virtual day by virtual day. Over time, the virtual children grow in height and weight. They eventually become adults. As they get older, depending on their weight, they develop different obesity-related health problems, such as cardiovascular disease, diabetes, and cancer, just as they would in real life. The virtual adults then have different health events, such as heart attacks, strokes, hospitalizations, and surgeries, all depending on how sick they are. Eventually, each virtual person dies from natural causes or obesity-related events.
Our model let us simulate what would happen to rates of overweight and obesity, different health outcomes, medical costs, and productivity if physical activity among children remained at today’s level or increased. Here’s what we found:
- If physical activity among children remains the same as it is now, more than 8 million youths would be overweight or obese at 18 years of age.
- If the percentage of children who are “active to a healthy level” increased from 33 percent to 50 percent, the number of obese and overweight youth would decrease by almost 350,000 (4.2 percent), which would save $8.1 billion in direct medical costs and $13.8 billion in lost productivity each year.
- If 75 percent of children were to reach the “active to a healthy level,” we would avert $16.6 billion in direct medical costs and $23.6 billion in lost productivity.
- If all children reached the “active to a healthy level,” that would reduce the percentage or overweight and obese youths by 15 percent and save $26.3 billion in direct medical costs and $36 billion in lost productivity. Fifteen percent may not sound like a lot, but it is actually quite significant since rates of overweight and obesity have been increasing.
Sadly, physical activity among children is decreasing rather than increasing: too much time on smartphones, computers, and television; too few physical education classes; declining participation in sports; more time spent riding in cars than walking or riding bikes.
If you’re a kid, or a parent of one, this should definitely matter to you. But it also matters if you aren’t a parent, or your young ones are grown and healthy. Overweight and obesity among children, which almost always stays with them as they become adults, cost everyone a lot of money. Insurance spreads others’ medical costs among everyone who pays for insurance or pays taxes. Lost productivity hurts businesses, which hurts the economy, which hurts all of us.
The good news is that even relatively small increases in children’s physical activity levels can improve long-term health and reduce health care costs.
A number of organizations are trying to increase physical activity among children. These include the Aspen Institute, the Laureus Sports for Good Foundation, the LA84 Foundation, the Partnership for a Healthier America, Up2Us Sports, the President’s Council on Fitness, Sports & Nutrition, and others. But as is the case for any team sport, they can’t do it alone.
All of us can help kids keep moving. Get kids to stop arguing with others on Facebook. Serve as a good example and exercise yourself. Build in family exercise or sports time. Encourage kids to walk or run rather than ride in cars. Realize that play time is as important as any other time. Coach youth sports. Get your kids to play sports, even if they won’t become stars. Encourage your local school system to beef up its physical education classes instead of dropping them. And to get back to Whitney Houston, find someone to dance with you.
Have fun, save money, and improve the present and future health of our children? That’s a no-brainer.
Bruce Y. Lee, MD, is the executive director of the Global Obesity Prevention Center, associate professor of international health at the Johns Hopkins Bloomberg School of Public Health, and a regular contributor to Forbes and the Huffington Post. Marie Ferguson, MSPH, is a senior analyst and coordinator of the Global Obesity Prevention Center’s Systems Science Core.