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

Objective: 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.