Eating Behaviors and Diet Quality: A National Survey of Australian Young Adults

Objective: To investigate associations between eating behavior constructs (social eating, perceived competence, habit automaticity, self-determined motivation) and diet quality among young adults. Design: Cross-sectional analysis. Participants: Young adults (n = 1,005; mean age, 21.7 ± 2.0 years; 85% female) enrolled in the Advice, Ideas, and Motivation for My Eating (Aim4Me) study. Main outcome measures: Four eating behavior measures collected via online surveys: Social Eating Scale, Perceived Competence in Healthy Eating Scale, Self-Report Behavioral Automaticity Index, and Regulation of Eating Behaviors scales. Diet quality was assessed using the Australian Recommended Food Score (ARFS) and percentage energy from energy-dense, nutrient-poor (EDNP) foods. Analysis: Multivariate linear regression investigating associations between eating behavior measures (independent variables) and ARFS and EDNP foods (dependent variables), adjusting for sociodemographic and lifestyle confounders. Results: Greater perceived competence in healthy eating and behavioral automaticity for consuming healthy foods, limiting EDNP food intake, and higher intrinsic motivation, integrated regulation, and identified regulation of eating behaviors were associated with higher ARFS and lower percentage energy EDNP foods (P < 0.001). Greater self-reported social influence on eating behaviors was associated with higher ARFS (P = 0.01). Higher amotivation was associated with greater % energy from EDNP foods (P < 0.001). Conclusions and Implications: Perceived competence, habit automaticity, and self-determined motivation are determinants of diet quality in young adults. These findings support the development of interventions that promote healthy eating habits by focusing on eating behavior constructs and evaluating their use in improving diet quality.