Food consumption by degree of processing and perceived mental and physical health: A cross-sectional analysis in the Moli-sani Study cohort

Background and aims: Diet quality has been linked to perceived mental and physical health, but the potential relationship with degree of food processing remains unexplored. We examined cross–sectional associations between food consumption categorized according to the Nova classification with perceived mental and physical health in a large cohort of adults. Methods: Cross-sectional analyses were run using data from 18,243 participants recruited in the Moli-sani Study (mean age 54 ± 11 years) in 2005–2010. The mental and physical component scores of the Short Form 36-item were calculated. Food intake was categorized through the Nova classification into four groups: 1) unprocessed/minimally processed foods; 2) processed culinary ingredients; 3) processed foods; 4) ultra-processed foods (UPFs). The Mediterranean Diet Score (MDS) was used to assess overall diet quality. Results: In multivariable-adjusted linear regression analyses, a larger dietary share of unprocessed/minimally processed food was linked to both higher mental (β = 1.39; 95%CI 0.98 to 1.79 for Q4 vs. Q1) and physical components scores (β = 0.33; 95%CI 0.06 to 0.60 for Q4 vs. Q1). Conversely, highest consumption of processed foods and UPFs was associated with lower values of the mental component scores (β = −1.36 points; 95%CI -1.79 to −0.92; and β = −0.57; 95%CI -0.94 to −0.21, respectively, for Q4 vs. Q1). Conclusions: Larger consumption of either processed foods or UPFs was associated with poorer mental health, whereas higher intake of unprocessed/minimally processed foods was linked to better perceived mental and physical health. These associations were independent of diet quality, suggesting that non-nutrient components may influence mental health outcomes. Future studies should more accurately reflect current patterns of processed food consumption in relation to perceived mental health.