Change in diet quality and differences in characteristics in Australian adults who completed the Healthy Eating Quiz: A cohort study.

Aim: Investigate changes in diet quality scores in adults who repeated a brief online dietary assessment tool, the Healthy Eating Quiz, and whether changes in diet quality varied by sociodemographic variables, dietary characteristics, or motivations for completing the tool.

Methods: This is a secondary analysis of longitudinal data collected July 2019-May 2022. Data from respondents aged 16-100 years who repeated the dietary assessment tool were analysed, including diet quality, measured using the validated Australian Recommended Food Score (range 0-73), sociodemographic and dietary characteristics (gender, age, socioeconomic status, vegetarian status, and meal sharing), and the main motivation for completing the tool. Paired t-tests assessed change in score between first and second tool completion (reported as mean (SD)). One-way ANOVA was used to test whether mean change in score differed by respondent sociodemographic, dietary, or motivation variables.

Results: Across 5189 respondents (73.6% female, 42.0 (17.4) years), mean score improved by 2.28 points during a mean 231 (11) days (p <0.001). Non-vegetarians reported a significantly greater improvement in score than vegetarians (2.39 (6.78) versus 1.56 (6.97) points, p = 0.003). Similarly, those who ate main meals alone improved more (2.70 (7.05) points) compared to those who ate with one (2.15 (6.67) points) or ≥two others (2.14 (6.72) points, p = 0.035).

Conclusion: Using the Healthy Eating Quiz, a diet quality assessment tool, on repeated occasions may contribute to improvements in diet quality in adults.