Planet Health

The objective of Planet Health is to evaluate the impact of a school-based health behavior intervention aimed at reducing obesity among young boys and girls in middle schools from grades 6 to 8. The practice was implemented using a randomized, controlled field trial with five interventions and five control schools with assessing the outcome of obesity before intervention and with follow-up measures for prevalence, incidence, and remission of obesity.

The practice is a school-based interdisciplinary intervention over the period of two years. The essential components of the intervention are “sessions focused on decreasing television viewing, consumption of high-fat foods, increasing fruit and vegetable intake, and increasing moderate and vigorous physical activity." The components consist of teacher training workshops, classroom lesions, PE materials, wellness sessions and fitness funds. The fitness funds were monetary incentives of $400 to $600 provided to intervention schools to teacher who submitted proposals consistent with Planet Health themes.

The practice was implemented by altering key physical activity and dietary risk factors. The interventions were integrated into existing class curriculums in schools to limit cost and improve replicability. The practice begins with students in grade 6 and 7 and continues over 2 school years. There are a total of 32 core lessons/themes addressed in classes with 1 lesson per subject (language, arts, math, science, and social studies) with 16 lessons administered in each year. There was an additional lesson developed around a 2-week campaign to reduce television viewing in households called “Power Down”. The lessons consisted of teacher resources; behavioral and learning objectives; procedure, extension, or homework activities; and student resources and handouts. Each classroom lesson had a behavioral objective that fit with 1 of the 4 behavioral targets of intervention.

The goal of Planet Health is to reduce childhood obesity among middle school students using a school-based interdisciplinary intervention focused on decreasing television viewing and consumption of high-fat foods, and increasing fruit and vegetable intake and moderate and vigorous physical activity.

These results cumulatively show that Planet Health and similar programs can reduce obesity and increase healthy food consumption in girls. They also show that a finding of a reduction in number of hours watching TV for girls can also predict reduction in obesity.

The type of study used to evaluate Planet Health was a randomized control trial in which ten schools from 4 communities were matched and then randomly assigned the intervention (n=5) or the control (n=5) groups. Planet Health’s main outcome was to reduce obesity by implementing four behavioral changes including reducing television viewing, increasing physical activity, decreasing high fat food intake, and increasing fruits and vegetable intake.

The study found a significant decrease in obesity among girls in the intervention schools versus girls in the control schools (p=0.03). There was no significant change in obesity for boys. After the data was adjusted, girls also showed a greater remission of obesity (p=0.04) than boys who had no difference (p=0.54). The study also examined differences between ethnic groups and found that African-American girls had the greatest reduction in obesity (p=0.007).

Planet Health also significantly reduced television time among girls (-0.58 hours, p=0.001) and boys (-0.40 hours, p<0.001) when compared to controls. Among girls, there was also less of an increase in estimated energy intake in the intervention schools versus the controls (p=0.05). Lastly, girls also had an increase in fruit and vegetable consumption (p=0.003) when compared with controls.