Program

Feb 03, 2013

OVERVIEW

 Planet Health is a two-year, school-based obesity prevention and weight reduction program for middle school students. The intervention focuses on increasing exercise and improving diet. An experimental study found impacts on obesity and consumption of fruits and vegetables among girls in Planet Health schools and significantly reduced television watching among both boys and girls. There was no impact on physical activity for either boys or girls. Another study found that girls in Planet Health schools were less likely to report disordered weight-control behaviors (i.e., purging or using diet pills for weight control). The impact on these disordered weight-control behaviors differed by baseline dieting status; there was an impact among girls in Planet Health schools who were not dieting at baseline but no impact on purging or diet pill use among girls who were dieting at baseline.

DESCRIPTION OF PROGRAM

Target population: Middle school students

Planet Health is designed to prevent and reduce obesity among middle school students. The program incorporates concepts from behavioral-choice theory and social cognitive theory, and it targets four specific behavioral objectives: reducing students’ television viewing, increasing students’ participation in moderate-to-vigorous physical activities, decreasing students’ consumption of high-fat foods, and increasing students’ consumption of fruits and vegetables.

Planet Health is a two-year program. Sixteen classroom lessons are taught during the first year of the program, and 16 are taught during the second year. Each lesson focuses on a specific behavioral objective and is taught as part of the curriculum for a particular course (language arts, math, science, or social studies). Each lesson can be taught in one or two 45-minute periods, depending upon the level of detail chosen by the teacher.

In addition to the components for use in academic classrooms, Planet Health provides materials for physical education classes. These materials focus on the themes of activity and inactivity, and include student self-assessments and goal-setting activities. A curriculum consisting of 30 five-minute micro-units is provided for physical educators, along with ideas for extending these micro-units in the second year of the program.

EVALUATION(S) OF PROGRAM

Gortmaker, S. L., Peterson, K., Wiecha, J., Sobol, A. M., Dixit, S., Fox, M. K., & Laird, N.  (1999). Reducing obesity via a school-based interdisciplinary intervention among youth.  Archives of Pediatric and Adolescent Medicine, 153, 409-418.

Evaluated population: Sixth- and seventh- grade students from ten public schools in the Boston, Massachusetts metropolitan area (1,295 students) served as the study sample for this investigation. Among the sample, 66 percent of the students were white, 13 percent were African American, 14 percent were Hispanic, and 17 percent were other of races and ethnicities.

Approach: The 10 schools were matched into pairs and then randomly assigned, within pairs, to either the treatment group or the control group. Treatment schools implemented the Planet Health program over the course of the 1995-96 and 1996-97 school years.  Students in 6th or 7th grade during 1995-96 and students in 7th or 8th grade during 1996-97 were exposed to the intervention. Students at control schools received their usual health and physical education curricula.

All physical education teachers at schools assigned to implement the Planet Health program took part in training workshops with project staff. Classroom teachers attended workshops or met with a field coordinator to receive training. Teachers were also given the opportunity to attend wellness sessions for their own wellness and to apply for fitness funds. Fitness funds were monetary incentives of $400 to $600 provided to schools to further Planet Health objectives.

Sixth- and 7th-grade students completed baseline assessments during the fall of 1995.  Follow-up measurements were collected during the spring of 1997. At both time points, students were weighed and measured, and they reported on their television viewing, physical activity, fat intake, consumption of fruits and vegetables, and overall energy intake.

Results: Over the course of the two-year Planet Health intervention, the prevalence of obesity among female students declined significantly in schools assigned to the intervention, and increased in schools assigned to the control group. The prevalence of obesity among male students declined in the intervention and control schools, and there was no significant difference in this decline between the two groups of schools.

By the end of the intervention, female students from intervention schools had significantly decreased their daily television viewing compared with female students from control schools resulting in a difference of more than half an hour. Male students from intervention schools had significantly decreased their daily television viewing by just under half an hour, compared with males from control schools.

Females in the intervention group also significantly increased their consumption of fruits and vegetables over the course of the intervention, and increased their daily energy intake by less than did females in the control group.  The evaluation did not find impacts for males on fruit and vegetable consumption or daily energy intake.

Planet Health did not have an impact on students’ participation in moderate-to-vigorous physical activities.

Austin, S.B., Field, A.E., Wiecha, J., Peterson, K.E., & Gortmaker, S. L. (2005). The impact of a school-based obesity prevention trial on disordered weight-control behaviors in early adolescent girls. Archives of Pediatric and Adolescent Medicine, 159, 225-230.

Evaluated population: A total of 627 girls ages 10-14 years participated in the study. The analyses excluded those with missing information on dieting, disordered weight-control behaviors, or ethnicity, as well as those who reported disordered weight-control behaviors at baseline, bringing the total number of girls included to 480 from the intervention schools (n=254) and control schools (n=226). The baseline characteristics of the intervention school and the control school samples did not significantly differ in average age (both 11.5 years), percent of overweight students (22 percent vs. 19 percent), percent dieting in the past month (27 percent vs. 28 percent), percent white (72 percent vs. 64 percent), percent Hispanic (10 percent vs. 11 percent), or percent reporting another ethnicity (10 percent vs. 9 percent). The intervention sample had a significantly lower percent of African American girls compared with the control sample (9 percent vs. 16 percent), which was taken into account in the analyses.

Approach: See Gortmaker et al (1999) for randomization procedure. Data on weight-control behaviors including dieting, vomiting, taking laxatives, and taking diet pills in the past 30 days were collected as self-report measures at baseline and at the end of the 21-month intervention. A single measure on disordered weight-control behavior was created for analysis by combining responses to the items on vomiting, laxatives, and diet pills. Analysis methods accounted for the fact that study participants were clustered by school.

Results: Girls in schools that received Planet Health were significantly less likely to report disordered weight-control behaviors (vomiting, taking laxatives, or taking diet pills) compared with girls in control schools. Among girls who were not dieting at baseline, there was a significant impact on disordered weight-control behaviors, but among girls who were dieting at baseline, no impact was found on disordered weight-control behaviors.

Cost-Effectiveness: A team of economists analyzed the data from this evaluation and estimated that Planet Health would prevent 1.9% of the female students from becoming overweight adults.  At a program cost of $33,677 (or $14 per student, per year), Planet Health could save $15,887 in medical care costs, and $25,104 in lost productivity costs.  This constitutes a net savings of $7,313 to society.  Thus, the program was deemed cost-effective.

SOURCES FOR MORE INFORMATION

References:

Austin, S.B., Field, A.E., Wiecha, J., Peterson, K.E., & Gortmaker, S. L. (2005). The impact of a school-based obesity prevention trial on disordered weight-control behaviors in early adolescent girls. Archives of Pediatric and Adolescent Medicine, 159, 225-230.

Gortmaker, S. L., Peterson, K., Wiecha, J., Sobol, A. M., Dixit, S., Fox, M. K., & Laird, N.  (1999). Reducing Obesity via a School-Based Interdisciplinary Intervention Among Youth.  Archives of Pediatric and Adolescent Medicine, 153, 409-418.

Wang, L. Y., Yang, Q., Lowry, R., & Wechsler, H.  (2003). Economic Analysis of a School-Based Obesity Prevention Program.  Obesity Research, 11(11), 1313-1324.

Curriculum materials available for purchase at:

http://planet-health.org/resourceStore.cfm

Contact information:

Stephen Gortmaker

677 Huntington Avenue

Kresge Building 7th Floor

Boston, MA 02115

sgortmak@hsph.harvard.edu

617-432-1029

KEYWORDS: Adolescence (12-17), Children, (3-11), Middle School, Males and Females, Female only, White or Caucasian, Black or African-American, Hispanic or Latino, Urban, Suburban, School-based, Cost, Manual, Health status/conditions, Nutrition, Obesity, Eating disorders

Program information last updated on 2/3/13