According to the National Center for Health Statistics, more than one in five children in the United States are overweight. The problem is creeping downward on the age scale, threatening even preschoolers. At the same time, type 2 diabetes — once called adult-onset diabetes — is affecting children as young as 4, while attention deficit hyperactivity disorder, or ADHD, is also on the rise.
Are the problems linked? David Ludwig, M.D., Ph.D., director of the Optimal Weight for Life program at Children's Hospital Boston, thinks they may be. He lays the blame squarely on diets heavy in processed and fast foods — a situation made worse by the constant barrage of TV commercials that make bad foods look so good to kids.
Young children are particularly vulnerable to media messages, as this is the age when they learn eating habits that will stay with them for a lifetime. The key, Dr. Ludwig says in an interview with Scholastic's Parent & Child magazine, is to send your own messages about smart eating by modeling healthy choices and habits.
Parent & Child: How much influence do TV commercials really have on young children's diets? Children aren't making food choices on their own.
Dr. Ludwig: While it's true that parents control what young children eat, children are nonetheless absorbing messages from TV. You can't underestimate the nag factor, when parents give in and buy stuff that's bad for their children. Unhealthy foods and snacks are presented to kids as being cool, appealing, and desirable. And, once they do go to school, they'll be trading foods they brought from home, and seeing the "cool" stuff other kids have.
P&C: So what can parents and teachers do to help?
Dr. Ludwig: If you start early and use this time to teach good eating habits, you can help prevent problems. By the time a child becomes overweight and parents become alarmed, food habits are already well established, and parent-child power struggles can arise.
Young children need to learn about a healthful diet and lifestyle from the people who love them and who have their best interests at heart. Children imitate adult behavior. Parents, in particular, should not only be supportive, they should also live a healthful lifestyle that includes eating nutritious foods and participating in regular exercise.
P&C: What contributes to poor eating habits and unhealthy lifestyles?
Dr. Ludwig: Families are busy, often working long hours and eating out or getting take-out more often. Children have less opportunity to see their parents preparing and eating nutritionally sound meals. Research shows that when meals are not eaten at home, the nutritional quality of the food goes down, and the number of calories consumed goes up.
Also, kids are eating more junk than they used to. Things that used to be rare treats are now daily indulgences. During any given week, three out of four children eat a fast-food meal one or more times a day. Rates of fast-food consumption may be lower for younger kids, but again, the youngest kids are laying down habits that will take hold later. Soda is another example: In the last two decades, soft drink consumption has gone up threefold. Kids used to drink three servings of milk for every serving of soda. Now those numbers are reversed.
P&C: We hear a lot about how the lack of exercise contributes to obesity and related health problems. What role does physical activity play?
Dr. Ludwig: You can partly blame a lack of exercise, but I think that incessant TV commercials are a bigger offender. The average child watches 10,000 TV commercials a year, the majority of which are for poor-quality, low-nutrition foods. Even if a child is getting decent physical activity, that's not enough to counteract the ill effects of eating too much fast food. For example, just one super-size fast-food meal contains a day's worth of calories for a child. Gym class or soccer practice can't reverse that. The child would have to run a marathon!
P&C: Are school meals a potential problem, too?
Dr. Ludwig: Many meals served at schools are not very nutritious. Parents can play an important role by becoming active in the PTA and writing to the school board to request improvement in the quality of food served.
Parents should also write their Congressional representatives. It's shortsighted of our government to scrimp on school spending; we end up paying a lot more in the long run with health problems related to obesity, such as type 2 diabetes.
P&C: How have recent diet trends among adults affected children's eating habits?
Dr. Ludwig: The single clearest trend in childhood diets has been the relative decline in fat as a percentage of total calories. It's the same thing that's happened with adult diets: We have gotten the message that all fat is bad. But It should be noted that some fats are very healthy, such as the fat in nuts, avocados, olive oil, and omega-3 fatty acids found in fish like salmon. When you cut all fat out of the diet, you miss out on healthy fats, too.
We've replaced fat with carbohydrates — and not the good kind. Instead of vegetables, fruits, beans, and other legumes, all of which are healthy carbs, we're eating more processed foods and refined starches — white bread, potatoes, white rice and pasta, and breakfast cereals. These foods all have what is called a high glycemic index. That means they cause a spike in blood sugar. You get a quick burst of energy, but then the blood sugar level drops quickly, stimulating more hunger and, in turn, overeating and weight gain. By contrast, foods with a low glycemic index, such as vegetables, grains, legumes, and other complex carbs, are gentler on blood sugar levels.
P&C: You've suggested a link between children's diets and the diagnoses of ADHD. Please explain.
Dr. Ludwig: It's not that foods with a high glycemic index cause ADHD, but we have observed that the percentage of refined starch and sugar in children's diets has increased along with the prevalence of ADHD.
Here's what happens: A child eats a breakfast that has no fat, no protein, and a high glycemic index — let's say a bagel with fat-free cream cheese. His blood sugar goes up, but pretty soon it crashes, which triggers the release of stress hormones like adrenaline. What you're left with, at around 10 a.m., is a kid with low blood sugar and lots of adrenaline circulating in his bloodstream. He's jittery and fidgety and not paying attention. That's going to look an awful lot like ADHD to his teacher. The possibility exists that in children predisposed to ADHD, quality of diet may have additional impact.
P&C: So what would constitute a healthy diet for kids, one that would help prevent obesity as well as behavioral problems?
Dr. Ludwig: Rather than focus on the amounts of fat and carbohydrates in the diet, it's much more sensible to recognize that both carbs and fat differ in quality. Parents should be sure their kids eat a diet heavy in good carbohydrates — whole grains, vegetables, most fruits, beans, legumes. And they should not lump all fats together as "bad." While you should certainly cut way down on saturated fats, like those in fast-food meals, don't completely cut out the beneficial fats mentioned earlier. That's good advice for all of us.