Chronic diseases and health promotion

Part Three. What works: the evidence for action

Chapter Two. Review of effective interventions

Vending machines. Spotlight: USA

Several interesting school studies have illustrated the ways in which vending machines can be used to promote a healthy diet. A study in the United Kingdom by the Health Education Trust, for example, found that when drink options were increased in school vending machines, even alongside regular options, children chose to drink milk, fruit juices and water. Involving students in decisions related to vending machine choices and the maintenance and location of the machines was important to success.

Venice High School in Los Angeles, USA, began offering a variety of waters, 100% juices and soy milk as well as cereal bars to replace the snacks which had previously been sold. After one year, snack sales in the student store were up by over US$ 1000 per month compared with the previous year. Two years after the changes, snack sales per month had roughly doubled.

Spotlight: School-based health programmes in the United States

The Child and Adolescent Trial for Cardiovascular Health (CATCH) is the largest school-based health study to have been conducted in the United States. It was designed to decrease cardiovascular risk factors in children through:

  • modifications to food services to reduce fat consumption;
  • smoke-free school policies;
  • school health education on cardiovascular risks;
  • a complementary family component to educate parents about cardiovascular risks;
  • physical education to increase the frequency and intensity of physical activity.

Results demonstrated that children from the intervention schools had lower consumption of total fat and saturated fat, and higher levels of self-reported physical activity, than those from comparison schools. Furthermore, intervention children maintained their results for three years without further interventions.

After five years of follow-up and no further intervention:

  • • menus from 50% of the former intervention cafeterias met the Eat Smart guidelines for fat compared with 10% of the former control schools;
  • student energy expenditure levels and proportion of time spent in moderate-to-vigorous physical activity in the intervention schools had been maintained, although vigorous activity had declined.

These results suggest that changes in the school environment to support health can be maintained over time. Staff training is an important factor in institutionalizing such programmes (Hoelscher DM, Feldman HA, Johnson CC, Lytle LA, Osganian SK, Parcel GS et al. School-based health education programs can be maintained over time: results from the CATCH Institutionalization Study. Preventive Medicine, 2004, 38:594–606).