Exploring the Lifestyle and Dietary Patterns of Food Supplement and Non-Food Supplement Users: A Cross-Sectional Study in the Portuguese Population

<b>Background:</b> The increasing use of food supplements (FSs) and the knowledge gaps among healthcare professionals (HPs) and non-healthcare professionals (nHPs) in Portugal regarding their influence on dietary patterns and health need investigating. This study aimed to explore FS users' lifestyle and dietary patterns, identifying differences and how professional background influences these patterns. <b>Methods:</b> A cross-sectional study was conducted among 1122 Portuguese adults aged 35 ± 14.0 yrs (between 18 and 85), via snowball sampling, collecting data on sociodemographic characteristics, dietary patterns, FS use, and health attitudes. Cluster analysis (k-means) revealed four patterns: (1) professional supplement users with a healthy diet (PSHD), (2) professional non-supplement users with a less healthy diet (PnSLHD), (3) non-professional supplement users with a healthy diet (nPSHD), and (4) non-professional non-supplement users with a less healthy diet (nPnSLHD). Logistic regression assessed associations with lifestyle traits. <b>Results:</b> Significant sociodemographic differences existed between HPs and nHPs. Higher nutritional knowledge and nutritionist recommendations were strongly associated with a healthier diet and FS use (PSHD, nPSHD). Smoking was associated with less healthy patterns (PnSLHD, nPnSLHD). Among nHPs, males were significantly more likely to belong to the nPSHD group (OR: 1.61) compared to females (OR: 0.61). Distinct dietary and lifestyle patterns among Portuguese FS users and non-users vary by background. <b>Conclusions:</b> The findings suggest that FS users often maintain healthier lifestyles, indicating that FSs typically supplement rather than compensate for poor habits.