| dc.description | As we gain a greater understanding about the factors that influence obesity, focus is being placed on prevention strategies to increase healthy eating and physical activity among youth. Yet, little is understood about how children and adolescents develop or choose health behaviours. Among adults, behavioural health experts have developed techniques directed at altering decisional balance (DB) to improve health behaviours. DB scales produce a difference score that represent an individual's relative balance of pros and cons for performing a health behaviour. This research examined the validity of youth DB measures for physical activity and nutrition behaviour among students in Grades 11, 7, and 3 using two informants: child self-report and parent proxy. First, youth DB measures were developed regarding choices about foods (calorie-dense vs. nutrient-dense) and activities (sedentary vs. active). Items were generated through literature searches, focus groups, and written feedback from parents. Second, expert advice and five statistical procedures on a survey of 296 youth were utilized to select items. The resulting measures showed an expected 2-factor structure, accounting for 35% and 30% of the variance for the activity and nutrition domains, respectively. Good psychometric properties, such as content validity with self-efficacy and one-week test-retest reliability, were observed for students in Grades 11 and 7, but not Grade 3. Finally, predictive validation studies measured physical activity and nutrition behaviours for a subsequent week using accelerometers and food frequency questionnaires. Results revealed that nutrition DB was significantly correlated with percent calories of fat and sugar consumed among adolescents in Grade 11 using self-report, and among youth in Grades 11 and 7 using parents as informants. Within the activity domain, DB did not predict average daily activity 'counts' among youth of any grade when using self report. However, with parent proxy reports, activity DB was temporally associated with activity 'counts' among Grade 11s. These results suggest that, depending on the informant, the youth DB measures were externally valid among Grade 11s for physical activity, and among Grade 11s and 7s for nutrition behaviour. Implications for future research and clinical interventions in the area of lifestyle modification among youth are discussed. | en_US |
