The Association between Ultra-Processed Foods and Depression, Anxiety and Sleep in Adults: A Cross-Sectional Study in Iran.

The increasing consumption of ultra-processed foods (UPFs) has raised concerns about their impact on human health, yet their relationship with mental health remains debated. This study aimed to investigate the association between UPF intake and sleep adequacy, as well as the severity of anxiety and depression in Iranian adults. A cross-sectional analysis was conducted on 5476 adults aged 35-65 years from the MASHAD study. Dietary intake was assessed using a validated food frequency questionnaire, and UPFs were classified based on the NOVA system. Depression and anxiety severity were measured using the Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI), respectively. Sleep adequacy was defined as more than seven 7 h of sleep per night, based on self-reported data. Higher UPF consumption was linked to increased odds of severe depression (OR = 1.25, 95% CI: 1.01-1.54), but this association lost statistical significance after full adjustment (OR = 1.25, 95% CI: 0.99-1.57). Subgroup analysis revealed a significant association in females, where high UPF intake was associated with a 44% higher risk of severe depression (OR = 1.44, 95% CI: 1.09-1.90,  = 0.01), whereas no such link was observed in males ( > 0.05). No significant associations were found between UPF intake and anxiety severity or sleep adequacy in either the overall population or gender subgroups (all  > 0.05). These findings suggest a possible association between UPF intake and depression severity among women, but not with anxiety or sleep. Further prospective and experimental studies are recommended to explore these relationships.