Health-related behaviours can play a key role in supporting both physical and psychological wellbeing. Investigating the psychological and social contexts through which these behaviours occur may help improve wellbeing outcomes at both an individual and population level. This thesis aimed to investigate the relationships between specific health behaviours, psychological wellbeing, and social contexts. Part A of this portfolio presents a systematic review of the contexts of women’s sobriety, considering psychological, social, and cultural influences. The review focused on women who chose sobriety outside the frame of alcohol addiction. The findings of the review highlighted how sobriety seems to be navigated through cultural and gendered norms, social belonging, identity construction, and requires significant, individual labour to maintain. Part B of the portfolio presents a cross-sectional study which investigated the relationships between meal sharing, loneliness, anxiety, depression, and dietary inflammation in a student population. Higher levels of depression and social anxiety were associated with more inflammatory diets. In contrast, greater meal sharing was associated with less inflammatory diets, suggesting a potential protective role of social eating practices. Loneliness showed a complex relationship: it was directly associated with less inflammatory diets but indirectly linked to greater dietary inflammation via depression and social anxiety, indicating an inconsistent mediation pattern. Meal sharing did not mediate the relationships between psychological factors and dietary inflammation. Overall, the findings of both studies highlight the importance of psychological and social factors in influencing health-related behaviours. This implies that interventions aimed at improving wellbeing should consider broader social and cultural contexts in connection with individual choices.