Exploring the Intersection Between Diet and Self-Identity: A Cross-Sectional Study With Australian Adults

Objective: Diet-related self-identity, which includes components such as individuals' overall dietary pattern and food choice motivations, is a strong predictor of health behaviors. This study sought to assess the variation in dietary patterns reported by a sample of Australian adults and their associations with diet quality. Design: Cross-sectional survey. Participants: Australian adults (n = 2,010) Variables measured: The main outcome measure was diet quality relative to the Australian Dietary Guidelines, measured by the Healthy Diet Score survey. Other outcomes captured included dietary patterns (eg, unrestricted, vegetarian, flexitarian, or ketogenic diets), diet-related self-identity constructs (centrality, prosocial motivation, personal motivation, and strictness), and sociodemographic characteristics (eg, age, sex, and education level). Analysis: Data were analyzed descriptively, and ordinary least squares regression was performed to identify significant predictors of diet quality. Results: Eighteen unique dietary patterns were reported. These were classified into 3 categories on the basis of the degree of restriction of core food groups. Diets based on restriction of animal protein were associated with the highest diet quality, including the highest consumption of fruits, vegetables, and whole grains, whereas restriction of other foods was associated with the poorest diet quality. Unrestricted diets reported the highest consumption of discretionary food (high in saturated fat, salt, or added sugar). Finally, the regression analysis found that diet quality was significantly predicted by dietary pattern and diet-related self-identity constructs (F[8, 1974] = 54.952; P < 0.0001; adjusted R-2 = 0.179). Conclusions and Implications: Dietary pattern and diet-related self-identity constructs are key determinants of diet quality. This has implications for future interventions, including that programs and messages could be tailored to ensure they align with the target population's self-identity and overall dietary patterns.