Objectives: (1) To measure the effects of different levels of exposure to a multiple-component garden-based intervention on middle school students' fruit and vegetable (F&V) consumption and related variables and (2) to determine the separate effects of each of the intervention components on F&V consumption.
Design: Unequal treatment-control posttest only.
Setting: Five middle schools in ethnically diverse communities.
Participants: Two hundred and forty-six adolescents (59% Hispanic; 70% low-income). Intervention. The Sprouting Healthy Kids intervention consists of six components: (1) in-class lessons, (2) after-school gardening program, (3) farm-to-school, (4) farmers' visits to schools, (5) taste testing, (6) field trips to farms.
Outcome measures: F&V consumption; motivation for eating F&V; self-efficacy for eating F&V; F&V preference; preference for unhealthy foods; knowledge.
Analysis: Linear regression models controlling for gender, ethnicity/race, and income.
Results: Compared with students who were exposed to less than two intervention components, students who were exposed to two or more components scored significantly higher on F&V intake, self-efficacy, and knowledge and lower on preference for unhealthy foods (p < .05). The farmers' visits, taste testing, and cafeteria components had the largest effect sizes but were not significant.
Conclusions and implications: Interventions targeting adolescent F&V behavior change should include multiple components such as farmers' visits to the school and taste testing.