Improving Teens’ Eating and Exercise Patterns

According to epidemiologists, most adolescents in the U.S. eat far too much fat and far too few fruits and vegetables, and don’t get enough daily exercise. The result has been an alarming rise in the number of overweight and obese teens. Recently, researchers from San Diego State University and the University of California, San Diego, designed several interventions to improve dietary and exercise patterns in middle-school students (Am J Prev Med 2003;24:209).

In the Middle School Physical Activity and Nutrition (M-SPAN) study, Dr. James F. Sallis and colleagues designed nutrition and physical activity interventions for 24 middle schools (grades 6 to 8) in San Diego (CA) County. Physical education classes were required daily for all students, and efforts were made to increase physical activity in PE classes and physical activity on campus before school, during lunchtime, and after school.

Since middle school cafeterias offer government-reimbursable lunches and breakfasts along with unregulated a la carte foods, the researchers worked with school food service staff and managers to provide more low-fat choices. One strategy was to identify food vendors who could provide tasty, low-fat foods at competitive prices. Since about a third of students brought lunches from home, educational materials were designed to encourage students to bring lower-fat lunches. None of the schools had vending machines.

Steps were taken to organize student health committees of 9 to 12 students, who were supervised by a faculty member. The goal was to plan a health-related activity at least once a month, such as assisting with taste tests, announcing after-school activities and creating posters promoting healthy lunch choices. The researchers also tried to educate parents about nutrition and activity through newsletters, posters, and by providing a brochure at open house and PTA meetings.

And the result of all this effort?

As a result of these interventions, physical activity at school increased for some students, but had no effect upon total and saturated dietary fat in foods purchased at, or brought to, school. All the efforts to increase physical activity at school did bring a significant change for boys, but not for girls.

It was unclear why the girls did not exercise more. The authors theorized that girls are normally less active than boys at these ages, and the educational efforts apparently made no difference in that pattern. Even though volunteers designed a variety of activities they thought would be attractive to girls, the approach did not work.

Unfortunately, there also was no change in the amount of fat in foods the students ate at school. Even though the authors sought to train school food service staff to modify recipes and to use methods that would reduce the fat in dishes sold in the school cafeteria, the new ideas often weren’t implemented. In addition, for some schools food was prepared by a central kitchen system, which made it impossible for individual schools to control ingredients or to change the ways food was prepared.

The single largest barrier was the requirement that food services be financially self-supporting. This policy created financial incentives to serve products students already preferred, especially processed foods advertised heavily in the mass media.

Schools took a financial risk when they tried to introduce new products, especially perishable fruits. Despite the in-school advertising and marketing efforts, the schools could not compete with the large commercial companies that advertised widely and effectively.

According to the authors, priorities for future research include improving school physical activity interventions for girls, working on the barriers that affect school food choices, and planning different approaches to school-health interventions. Financial incentives for schools, which might increase the amount and types of healthier foods available to students, may prove to be a necessary part of the equation.