Dietary Psychosocial Mediators of Vegetable Intake in Schoolchildren From Low-Income and Racial and Ethnic Minority US Families: Findings From the Texas Sprouts Intervention

Abstract

Background: Numerous school-based interventions have used cooking and gardening approaches to improve dietary intake; however, research is limited on the mediation effect of dietary psychosocial factors on the link between the intervention and increased vegetable intake, particularly in children from low-income and racial and ethnic minority US families.

Objective: Our aim was to examine the effects of the Texas Sprouts intervention on dietary psychosocial factors related to intake of vegetables, and whether these psychosocial factors mediate the link between the intervention and increased intake of vegetables in schoolchildren from low-income and racial and ethnic minority US families.

Design: This was an analysis of data on secondary outcomes from the Texas Sprouts program, a 1-year school-based gardening, nutrition, and cooking cluster randomized controlled trial consisting of elementary schools that were randomly assigned to either the Texas Sprouts intervention or to control.

Participants/setting: Participants were 2,414 third- through fifth-grade students from low-income and racial and ethnic minority US families from 16 schools (8 intervention and 8 control) in Austin, TX.

Intervention: The intervention group received eighteen 60-minute gardening, nutrition, and cooking student lessons in an outdoor teaching garden and 9 monthly parent lessons throughout the academic year.

Main outcome measures: Child psychosocial and dietary measures were collected at baseline and post intervention via validated questionnaires.

Statistical analyses performed: Generalized linear mixed models assessed the intervention effects on dietary psychosocial factors. Mediation analyses examined whether these psychosocial factors mediated the link between the intervention and increased child vegetable intake.

Results: Children in Texas Sprouts, compared with controls, showed significant increases in the mean scores of gardening attitudes, cooking self-efficacy, gardening self-efficacy, nutrition and gardening knowledge, and preferences for fruit and vegetables (all, P < .001). Each of the dietary psychosocial factors mediated the association between the Texas Sprouts intervention and child vegetable intake.

Conclusions: Besides targeting dietary behaviors, future school-based interventions should also focus on understanding the mechanisms through which teaching children to cook and garden influence dietary psychosocial factors as mediators of change in healthy eating behaviors.

Trial registration: ClinicalTrials.gov NCT02668744.

Keywords: Cooking intervention; Dietary psychosocial factors; Gardening; Nutrition; Self-efficacy.

Figure 1.

CONSORT Flow Diagram for the Texas Sprouts CRCT

Figure 2

Path analysis – Gardening attitudes, cooking and gardening self-efficacy, nutrition and gardening knowledge, and preferences for fruit and vegetables mediated the relationship between the Texas sprouts intervention and vegetable intake in 2,414 3^rd-5^th grade students ^a Values shown are unstandardized regression coefficients *p < 0.01, **p < 0.001.