Characteristics of control variables.

Social connections are essential for human health. While curiosity and empathy are crucial psychological factors for a fulfilling life connected with others, it is unclear if acquired environmental factors influence them. In this cross-sectional observational study, 1,311 men and women aged 20–79 years living in Japan were observed to explore how lifestyle factors such as diet, sleep, and leisure activities (such as exercise and hobbies) impact curiosity and empathy. A hierarchical multiple regression analysis revealed that diet and leisure activities impacted curiosity, whereas hobbies influenced cognitive empathy but not affective empathy. Structural equation modeling indicated that men’s curiosity was influenced by diet, leisure activities, and work, whereas women’s curiosity was influenced by leisure activities and work. These findings suggest that diet and leisure activities can enhance curiosity and cognitive empathy, leading to improved well-being.