More American children and youth are fat than ever before, and a Harvard University researcher has attributed this “fattening of America” to a generation of couch potatoes who spend as much time watching television as in the classroom.
Rates of obesity among children and adolescents went up an average of about 45% between 1960 and the early 1980s, according to Steven Gortmaker, associate professor and acting chairman of the department of behavioral sciences at Harvard.
A “key factor” in explaining the rise are 1983 studies that show children spend an average of at least 25 hours a week in front of the television, said Gortmaker, who speculated that the actual number of viewing hours is higher.
“Television viewing for children is now practically a full-time job, equal to the time spent in school,” he said, adding that television viewing is up from an average of 18 hours a week in 1968.
Calling his theory the “couch potato hypothesis,” Gortmaker said diet, a general decline in physical activity and television commercials--which reinforce the appeal of high-calorie foods--combine to contribute to the dramatic increase in overweight youngsters.
Gortmaker addressed participants of the 71st annual meeting of the American Dietetic Assn. in San Francisco.
The link between television viewing and obesity rates also holds true for adults, Gortmaker said, reporting that one study showed adults who watch one hour of television a day or less have a 3% chance of being obese, compared to a 25% chance of obesity among adults who watch three hours a day.
Specifically, Gortmaker found that between the late 1960s and 1980, obesity rates went up 54% among children ages 6 to 11. Rates of super-obesity went up 98% in the same age group. Among youths aged 12 to 17, obesity went up 39%, and super-obesity rose 64% during the same period.
Gortmaker said obesity and super-obesity were measured with a skin fold test that does not readily translate into percentage of body fat or other measurements.
The greatest increase among males was between the ages of 6 and 11, while the biggest jump among females was in those 12 to 17. Although obesity was less prevalent among blacks than whites, the gap has narrowed recently, Gortmaker said.
Obesity is equally prevalent among wealthy and poor children, Gortmaker found. The greatest number of obese youth are found in the Northeast, while the fewest are in the region west of the Mississippi River, he said.
Obese children face health risks, including hypertension, psycho-social damage and respiratory and orthopedic problems, Gortmaker said. Overweight youth also tend to grow up and become overweight adults, he added.
To counter the trend, Gortmaker recommended individualized programs to target overweight youth and school and community-based nutrition programs.
In another presentation, a Houston researcher reported that dieting has become the norm among U.S. women and has become common among young children.
“It’s not uncommon to see children in second, third and fourth grade begin to abnormally restrict their caloric intake,” said John Foreyt, associate professor at Baylor College of Medicine in Houston.
One study revealed that a group of well-meaning parents, fearful that their young infants would become obese, actually caused nutritional dwarfing in their babies by restricting their food intake.
“Today we have become a nation obsessed with body shape, body size,” Foreyt said. “Women, in particular, are not satisfied with their bodies today, either size or shape.”
Although the average U.S. man would like to lose one pound, the average woman wants to lose 11 pounds, he said.
“Why is this?” he asked. “We today have the first generation of girls growing up whose mothers had tremendous pressures to diet.”
Popular images of women, including beauty queens and fashion models, feature women who typically weigh only 82% of average body weight, Foreyt said, cautioning that such images can have harmful psychological effects on women who compare themselves to these “very, very skinny women.”
Chronic dieting, known as “cycling,” can lead to harmful food obsessions; emotional problems that include depression; anxiety and withdrawal, and physical changes from sleep disturbance to a lowered metabolic rate that can inhibit weight loss.
Chronic dieting inhibits the weight-loss process, while shortening the time it takes to regain weight, he said. It can also cause body fat to shift upward, where it can be more physically harmful.
“Mild obesity in women does not constitute a health risk for women,” said Foreyt, who urged health-care professionals to address the underlying psychological issues, eating habits and unattainable goals that contribute to chronic dieting.