PWM: School-based Programs to Prevent Overweight (2006)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
The study aimed to assess the impact of the programs on cardiovascular risk factors using a modified factorial design to examine fitness and nutrition programs alone and in combination and to compare the effects of school-based and home-based nutrition programs.
Inclusion Criteria:
All children enrolled in Year 6 classes at the selected schools were invited to join the project.
Exclusion Criteria:

See above inclusion criteria.

Description of Study Protocol:

The principal targets of the nutrition programs were to increase consumption of fruit, vegetables, whole-grain bread, and cereals relative to other foods and to decrease the consumption of fatty, sugary, and salty foods relative to other foods. School-based nutrition program: This consisted of 10 1-hr lessons which aimed to improve knowledge, attitudes, and eating habits.

Health-based nutrition program: This included 5 nutrition messages using comics delivered through the schools. Each comic contained educational material for the child and additional material for the parents who, throughout the program, were encouraged to become involved with the child’s nutrition education by assisting with homework exercises, helping to prepare healthy recipes, and other activities.

Fitness education program: This included 6, 30-min classroom sessions aimed at providing the children with a rational basis for their activity programs and for exercise in general. The aims of the program were to encourage children to choose physically active options as opposed to passive options, to take part in daily fitness activities sufficient to increase heart rate to 150-170 beats/min for at least 15 min, & to improve levels of physical fitness.

Control group: Schools randomly allocated to the control group were visited by the research team and subjected to the same measurements as the other groups but no nutritional or physical fitness programs, additional to those already being taught were introduced.

Data Collection Summary:

Dependent

Knowledge about food, exercise & health, Attitudes to food, exercise & health, Dietary intakes: fats, sugars & proteins - % of total kcal (2-day diet record), Physical activity levels, Physical fitness (1.6 km run & the Leger shuttle run), Body composition (height, weight to calculate BMI, triceps & subscapular skinfold to calculate % body fat), Blood pressure, Blood cholesterol.

Independent

1of 6 groups/programs: physical fitness, physical fitness + school nutrition, school-based nutrition, school nutrition & home nutrition, home-based nutrition or a control group.

Control Variables

Data were analyzed separately for boys & girls. All follow-up measurements were adjusted for baseline values.

Statistical Analysis

Regression models were used for comparison of results at follow-up with responses in the control group.

Description of Actual Data Sample:

Original Sample: 1,147 10- to 12-year olds from 30 schools were allocated to 1 of 5 health programs.

Withdrawals/Drop-Outs: not stated.

Final Sample: Follow-up records were obtained from 921; matched pairs of baseline and follow-up records were available for 869 children distributed among the 6 study groups.

423 males, 446 females.

Race/Ethnicity: not stated – Australian children.

SES: This sample of schoolchildren is considered to be representative of the socioeconomic mix of the community.

Age: 10- to 12-years-old

Location: West Australia

Summary of Results:

Sugar

(Boys) There was a decrease in sugar intake significantly different from controls in both fitness groups and in school nutrition + home nutrition group.

(Girls) There was no significant difference from controls in sugar intake with a pattern of a decrease in all groups except for the two home nutrition groups in which sugar intake tended to increase.

Fat

(Boys) Following intervention, the contribution of fat to daily energy, adjusted for baseline levels, increased in each treatment group for boys relative to controls.

(Girls) Total fat intake, adjusted for baseline levels, decreased relative to controls in all except the school nutrition group but the fall was significantly different from controls only in home nutrition group.

Saturated Fat

(Girls) Intake of saturated fat decreased in all treatment groups with a significant difference from controls in the school + home nutrition and home nutrition group.

(Boys) No significant differences from controls were identified but tended to increase intake of saturated fats in all but the school nutrition group.

Polyunsaturated: Saturated Fat Ratio

The P:S ratio at baseline was 0.40 for boys and 0.38 for girls, with a significant change following intervention only in girls in the school + home nutrition group.

Fat-Sugar Seesaw

Changes in sugar intake correlated negatively with changes in fat intake in both boys & girls.

Total Energy

Energy intake did not change significantly during the intervention, even in the fitness group (for boys &girls).

Protein

Protein intake increased slightly following the intervention although there were significant increases compared with controls only in boys in the fitness + school nutrition, school nutrition, and school + home nutrition groups.

Fiber

There was an increase in fiber intake significantly different from controls for girls in the fitness group and for both boys and girls in the school + home nutrition group.

Salt

There was a fall in salt intake compared with controls in boys, although these differences were significant only in school nutrition group. In girls, salt intake tended to increase in all groups relative to controls and the difference from the change in the control was significant for both fitness groups & in the school nutrition group.

Physical Fitness

Marked increases in endurance fitness compared with controls were observed after intervention in boys and girls participating in the fitness program.

(Girls) in the school + home nutrition group also showed significant improvements in the Leger run compared with the controls. Girls benefited more than boys from the fitness programs with almost twice the increase in Leger scores compared with boys in the same fitness program groups.

Anthropometric

Triceps skinfolds decreased significantly in both boys & girls in the fitness + school nutrition group compared with controls.

There were no significant differences in change in subscapular skinfolds nor in the percentage body fat or BMI relative to controls. *** Within-observer variability was acceptable; however between-observer variability for triceps and subscapular skinfolds was high.

Blood Pressure

A significant decrease in BP relative to controls was seen only for DBP in girls in the 2 fitness programs. Although there was a similar pattern for SBP in girls, these changes were not significantly different from controls.

Blood Cholesterol

Blood cholesterol increased significantly for the whole cohort, from 4.26 (3.58-4.94) to 4.32 (3.55-5.09) mmol/L after the intervention period. Increases were significantly greater than controls for girls in all intervention groups and for boys in the fitness group.

Author Conclusion:
"Teacher-implemented health packages are feasible with minimal training but programs should differ between boys & girls."
Funding Source:
Reviewer Comments:
For boys, there was no trend to greater greater cardiovascular risk at baseline in those who did not attend follow-up but for girls, non-attenders tended to be less fit and have higher blood pressure at baseline than those who completed the study.