Group Randomized Trial of Healthy Eating and Gardening Intervention in Navajo Elementary Schools (Yéego!)

Few healthy eating, school-based interventions have been rigorously evaluated in American Indian communities. Gardening and healthy eating are priorities in the Navajo Nation. Collaborations between researchers and local partners supported the design and implementation of this project.

The Yéego! Healthy Eating and Gardening Study was a group-randomized controlled trial to evaluate a school-based healthy eating and gardening intervention in 6 schools in the Navajo Nation. Schools were randomized 1:2 to intervention or comparison.

The Shiprock and Tsaile/Chinle areas in the Navajo Nation were selected. Elementary schools were screened for eligibility. All students in third and fourth grades were invited to participate in the assessments.

Delivered during 1 school year in the intervention schools, the intervention included a culturally relevant nutrition and gardening curriculum and a school garden.

Student self-efficacy for eating fruits and vegetables, student self-efficacy for gardening, and student healthy foods score from a modified Alternative Healthy Eating Index were assessed in third and fourth graders at the beginning and end of a school year affected by the COVID-19 pandemic. Primary analyses used repeated measures linear mixed models accounting for students nested within schools to estimate the intervention effect and 95% CIs.

Students in the intervention schools had self-efficacy scores for eating fruits and vegetables that were 0.22 points greater (95% CI=0.04, 0.41) than those in the comparison schools, although the student healthy foods score increased in the intervention schools by 2.0 (95% CI=0.4, 3.6); the differential change was modest at 1.7 (95% CI=-0.3, 3.7). The self-efficacy to grow fruits and vegetables in the school garden increased among those in the intervention schools (OR=1.92; 95% CI=1.02, 3.63) but not significantly more than it increased in the comparison schools (OR=1.29; 95% CI=0.60, 2.81).

The intervention was efficacious in improving self-efficacy for eating fruits and vegetables among third- and fourth-grade students over a school year. The findings warrant further evaluation of the intervention in larger-group randomized trials with schools in Navajo communities.

This study is registered at clinicaltrials.gov NCT03778021.