Fast-Food Teens In All Sizes
Three out of four American teens eat fast food at least once a week. So why do some become overweight, while others do not? That is the question researchers at Children's Hospital in Boston tried to answer.
Over a two-day period, researchers observed the eating habits of lean and overweight teens and found that lean adolescents who eat a large fast-food meal seem to compensate by eating less of other food throughout the day.
The obese adolescents, however, had a particular problem compensating for the calories in a large fast-food meal -- consuming 400 more calories on days when they had a fast-food meal, compared to days when they did not.
The Early Show medical correspondent Dr. Emily Senay explains the study recently published in the Journal of the American Medical Association.
Researchers from Children's Hospital in Boston observed 54 adolescents between the ages of 13 to 17 years old while they consumed fast food at a local food court.
The subjects chosen for the study were categorized into two groups: lean or overweight. They were allowed to eat as much or as little as they wanted. Researchers recorded the amount of the food consumed and its nutritional value.
Another goal of the study was to compare how kids ate on days when they consumed fast food, compared to days in which they didn't eat fast food.
So, Senay says, the researchers called each teen and asked him or her about what foods they had eaten on specific days. They also asked them to estimate how much physical activity they did on those days.
As expected, during the first phase of the study, overweight participants ate more than lean participants, regardless of need. All kids consumed calories equivalent to more than 61 percent of their estimated daily energy requirement.
The researchers also found that overweight participants consumed 409 calories more on fast-food days. In contrast, lean kids consumed the same numbrer of calories on both fast-food and non-fast food days.
In both groups, lean and overweight children overate. But, overeating was especially pronounced among the overweight.
Thus, researchers concluded that, "overweight individuals do not compensate completely for the massive portion sizes characteristic of fast food today."
The study did not look at how the eating habits of the lean and overweight differ. Senay says it could be that failure to compensate for large fast-food meals is an inherent trait, which causes obesity in certain individuals. Or, it could be a secondary event that happens after a person becomes obese. Or, it could be something altogether different.
In a recent article, the U.S. Centers for Disease Control and Prevention said obesity among adults and children is a major public health concern.
Thus, kids who have a weight issue have to be aware of the calories they are consuming in a fast-food meal. The study's lead researcher, Dr. David Ludwig, suggests that fast food is designed to be consumed in larger quantities, but it is less filling.
"Highly processed and tasty fast food goes down more easily," he said. "Consuming the equivalent to a 1,600-calorie fast food meal in vegetables and whole grains requires chewing and time, and would leave the body feeling full long before reaching the same level."