Background Sustainable and healthy eating plays a crucial role in reducing environmental impact and protecting long-term human health. However, the development of such dietary behaviors depends not only on general awareness but also on individuals’ capacity to translate nutritional knowledge into consistent, actionable food choices. Understanding how this transformation occurs is particularly important for young adults, who are in a formative stage of establishing lifelong eating habits. Examining the psychological mechanisms that facilitate the conversion of knowledge into behavior may help promote sustainable, healthy dietary practices in this age group. Objective This study aimed to examine the serial mediating roles of diet self-efficacy and mindful eating in explaining how nutrition knowledge is translated into sustainable and healthy eating behaviors among sports science students. The research aimed to elucidate the widely discussed knowledge–behavior gap in dietary practices through its underlying psychological mechanisms. Methods The study used a correlational research design and included 671 sports science students. Data were collected using the Nutrition Knowledge Scale, Diet Self-Efficacy Scale, Mindful Eating Scale, and the Sustainable and Healthy Eating Behaviors Scale. Hypotheses were tested using a serial mediation analysis (Model 6) with Hayes’ PROCESS Macro. Results Nutrition knowledge was significantly associated with sustainable and healthy eating behaviors both directly and indirectly. While nutrition knowledge positively predicted diet self-efficacy and mindful eating, diet self-efficacy was negatively associated with mindful eating. Furthermore, the serial indirect effect through diet self-efficacy and mindful eating was negative, suggesting a more complex, non-linear mechanism than initially hypothesized. These findings suggest the presence of potentially competing self-regulatory processes rather than a purely facilitative pathway. The serial mediation pathway was statistically significant. Conclusion The findings indicate that nutrition knowledge alone is insufficient; self-efficacy beliefs and mindfulness-based self-regulation processes are critical for transforming knowledge into behavior. These results suggest that interventions aimed at improving sustainable and healthy eating behaviors should integrate cognitive expertise with the development of psychological skills.
CABA et al. (Fri,) studied this question.