Ultra-processed food consumption and pro-inflammatory potential of the diet: a cross-sectional analysis of the NutriNet-Brasil study, 2020-2025.

BACKGROUND

The consumption of ultra-processed foods (UPF) has been associated with diseases in which inflammation plays a key role. The Dietary Inflammatory Index (DII) was developed as a tool to estimate the inflammatory potential of the diet; however, the association between UPF consumption and higher DII scores remains insufficiently explored.

OBJECTIVE

To investigate the association between UPF consumption and the DII.

DESIGN

This was a cross-sectional study.

PARTICIPANTS

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Setting

Data from 36,669 adults enrolled in the NutriNet-Brasil cohort between 2020 and 2025 were analyzed.

MAIN OUTCOME MEASURES: The outcome was the DII, calculated as proposed in previous studies, based on dietary components such as macronutrients, vitamins, minerals, and bioactive compounds STATISTICAL ANALYSES: UPF contribution to energy intake was estimated using the mean of 2-3 24-hour recalls (Nova24h). Associations between UPF consumption (percentage of energy, in quintiles and as a continuous variable) and the DII were analyzed using multiple linear regression models.

RESULTS

The mean DII was 1.31 (95% CI: 1.28-1.33) and mean UPF contribution was 22.7%, ranging from an average of 7.50% (Q1) to 41.14% (Q5). In adjusted models, the DII increased linearly across quintiles of UPF intake (p for linear trend < 0.001). The estimated DII score in the highest quintile (Q5: 2.57) was eleven times higher than in the lowest quintile (Q1: 0.22), demonstrating a strong positive association between UPF consumption and the pro-inflammatory potential of the diet. As a continuous variable, each 10% increase in UPF energy was associated with a 0.70-point higher DII (p <0.001).

CONCLUSIONS

Higher UPF consumption was associated with a more pro-inflammatory dietary pattern. These findings highlight the potential role of UPF consumption in shaping the inflammatory potential of the diet and support further research on its implications for diet-related health outcomes.