A cluster randomised controlled trial of an intervention based on the Health Action Process Approach for increasing fruit and vegetable consumption in Iranian adolescents.
OBJECTIVE
To evaluate an intervention programme based on the Health Action Process Approach and designed to increase the intake of fruit and vegetables (F&V) among Iranian adolescents aged 13 to 18.


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.
['Lin|Chung-Ying|CY|', 'Scheerman|Janneke F M|JFM|', 'Yaseri|Mehdi|M|', 'Pakpour|Amir H|AH|', 'Webb|Thomas L|TL|']
D000293:Adolescent D016000:Cluster Analysis D004032:Diet D005260:Female D005638:Fruit D006293:Health Promotion D006801:Humans D007492:Iran D008297:Male D015397:Program Evaluation D011446:Prospective Studies D014675:Vegetables
intervention fruit and vegetable adolescent behaviour randomised-controlled trial