Healthy eating intentions among adults in China: a cross-sectional study of northern and southern regions and city tiers based on the theory of planned behavior.

Objectives: The theory of planned behavior (TPB) has been widely employed to predict healthy eating intentions. Regional differences may affect dietary habits, health status, and personality traits, whereas variations in urbanization influence accessibility to fresh and healthy food, thereby impacting TPB components. This study aimed to explore whether regional differences between northern and southern China including city-tier development are associated with healthy eating intentions among Chinese adults.

Methods: The study included data from 2,114 Chinese adults aged 19-64 years collected between 2019 and 2023. Participants were categorized by geographic region (north or south) and city-tier status (first-tier or other).

Results: Compared to individuals from northern first-tier cities, those from southern regions exhibited stronger attitudes, perceived behavioral control (PBC), and intention to eat healthily. Participants from other cities in the north had more positive attitudes, subjective norms, PBC, and intentions to participate in healthy eating. Furthermore, residents of southern cities revealed weaker subjective norms than those of cities in the north. The adjusted odds ratio (OR) for compliance with intention to engage in healthy eating was higher among participants from other cities in both the north and south compared to those from northern first-tier cities (northern other cities: OR = 2.43, 95% confidence interval [CI]: 1.49-3.97, P < 0.001; southern other cities: OR = 1.95, 95% CI: 1.08-3.51, P = 0.027). No significant differences existed among the subjects from first-tier cities according to their geographic regions. These trends remained consistent even after including the interaction term between geographic regions and city-tier classification.

Conclusion: These findings underscore the complexity of regional variations influencing dietary intentions and indicate that tailored health promotion strategies should incorporate regional characteristics. Future research should explore underlying factors, including regional cultural influences, to better inform policies and interventions.