A cluster randomised controlled trial of an intervention based on the Health Action Process Approach for increasing fruit and vegetable consumption in Iranian adolescents
Design: A randomised controlled trial with three arms examined the short- (1 month) and long-term (6 months) effects of the intervention. There were two intervention groups (one included adolescents only [A group; n = 510]; the second included mothers and adolescents [M + A group; n = 462]) and a control group (n = 483). All participants were recruited from schools.
Main outcome measures: Social cognitions, self-regulatory processes and F&V intake.
Results: The intervention led to an increase in F&V intake for adolescents in the short and long terms. Adolescents in the M + A group increased their F& V intake more than adolescents in the A group. Outcome expectancies, self-monitoring, intentions, action and coping planning, perceived social support and behavioural automaticity mediated the effect of the intervention on F&V intake.
Conclusion: The theory-based intervention led to an increase in F&V intake and promoted more positive social cognitions and self-regulatory processes among Iranian adolescents. The findings also provide evidence that involving mothers in an intervention can confer additional benefit.
Document Type: Research Article
Affiliations: 1: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong 2: Department of Health, Sports & Welfare/Cluster Oral Hygiene, Inholland University of Applied Sciences, Amsterdam, The Netherlands 3: Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran 4: Social Determinants of Health Research Center, Qazvin University of Medical Sciences, Qazvin, Iran 5: Department of Psychology, The University of Sheffield, Sheffield, UK
Publication date: December 2, 2017