UC Irvine

Dietary patterns and food choices play a significant role in the health of communities and individuals. Evidence suggests that while college students do not experience a high prevalence of chronic illness, their diet quality is extraordinarily poor. This dissertation performed a systematic review and conducted a randomized controlled trial to evaluate the impact and effect of simple and personalized diet-related behavioral interventions on diet quality among young adults, specifically those who are attending college. First, a systematic review was conducted to identify and synthesize the findings of previously published studies among young adults, aged 18-35 years, which tested the effects of easy-to-learn interventions when compared to passive or alternative treatments on overall diet quality or constituents of diet quality. Next, cross-sectional analysis of baseline data from a behavioral intervention study for improving diet quality in college students was conducted with the goal of identifying associations between perceived stress and diet quality, and the moderating role of food security status. Finally, a randomized controlled trial investigated the effects of a simple and individually modifiable intervention on the diet quality of college students. Participants in the control group were asked to read and consider the principles of the dietary guidelines for Americans, and participants in the experimental group selected two dietary change statements which were printed into keychain tags and carried on their person to provide a consistent reminder of their desired dietary improvement. Five of the nine studies included in the systematic review reported significant improvement to the selected dietary outcome between groups. Four of these studies used an implementation intentions approach that had participants write out a simple dietary behavior directive and carry it with them for the study duration, and three reported significant differences between groups. The average Cohen’s d effect size for all included studies was 0.26. Next, results from the cross-sectional analysis reported no significant associations between perceived stress and HEI-2020 or any component of diet quality, however, there were significant interactive effects for food security and perceived stress on total vegetable and total protein component scores. Lastly, results of the trial intervention reported no significant differences within or between the control and experimental groups at any time point for HEI-2020 total or component scores, with the exception an increase in total vegetable score from baseline to week 4 in the control group only. Despite the non-significant findings, the majority of the participants reported satisfaction with the intervention’s ease and utility. Prior evidence suggests that small-scale and individualized efforts can play a role in promoting healthy behaviors in college students. Additional efforts to improve diet quality should consider both the personal and structural circumstances that students encounter during their time in academia.