Adherence to the ultra-processed dietary pattern and risk of depressive outcomes: Findings from the NutriNet Brasil cohort study and an updated systematic review and meta-analysis.

BACKGROUND & AIMS: We aimed to analyze the prospective association between adherence to the ultra-processed dietary pattern and risk of depressive outcomes using original data from the NutriNet Brasil cohort and via a systematic review and meta-analysis of observational studies that have investigated the same association. METHODS: In our original research analysis, we used data from 15,960 adults (≥18 y) participating in the NutriNet Brasil cohort study, free of depression or depressive symptoms during the baseline (77.5% women, 45.8 ± 13.0 y). The mean dietary share of ultra-processed foods (%Kcal/d), calculated from two baseline 24-h dietary recalls, was used to measure the adherence to the ultra-processed dietary pattern. New cases of depressive symptoms were assessed using the Patient Health Questionnaire-9 over the follow-up period (mean: 18.3 months). Cox proportional hazards models were used for the main analyses. In our systematic review and meta-analysis, we incorporated effect estimates from six prospective cohort studies that have examined the same association, including ours. RESULTS: In the adjusted model, each 10% increase in the dietary share of ultra-processed foods was associated with a 10% increase in the hazard of incident cases of depressive symptoms (HR:1.10; 95%CI: 1.07-1.14). This association was slightly attenuated in the models including potential mediators. In our meta-analysis of six prospective studies, high versus low exposure to ultra-processed foods was associated with a summary hazard ratio of depressive outcomes of 1.32; 95%CI: 1.19-1.46; I2: 71%. CONCLUSION: A higher adherence to the ultra-processed dietary pattern was associated with a higher risk of developing depressive outcomes in the NutriNet Brasil cohort and in the meta-analysis.

Categorising ultra-processed foods in large-scale cohort studies: evidence from the Nurses' Health Studies, the Health Professionals Follow-up Study, and the Growing Up Today Study.

This manuscript details the strategy employed for categorising food items based on their processing levels into the four NOVA groups. Semi-quantitative food frequency questionnaires (FFQs) from the Nurses' Health Studies (NHS) I and II, the Health Professionals Follow-up Study (HPFS) and the Growing Up Today Studies (GUTS) I and II cohorts were used. The four-stage approach included: (i) the creation of a complete food list from the FFQs; (ii) assignment of food items to a NOVA group by three researchers; (iii) checking for consensus in categorisation and shortlisting discordant food items; (iv) discussions with experts and use of additional resources (research dieticians, cohort-specific documents, online grocery store scans) to guide the final categorisation of the short-listed items. At stage 1, 205 and 315 food items were compiled from the NHS and HPFS, and the GUTS FFQs, respectively. Over 70 % of food items from all cohorts were assigned to a NOVA group after stage 2. The remainder were shortlisted for further discussion (stage 3). After two rounds of reviews at stage 4, 95⋅6 % of food items (NHS + HPFS) and 90⋅7 % items (GUTS) were categorised. The remaining products were assigned to a non-ultra-processed food group (primary categorisation) and flagged for sensitivity analyses at which point they would be categorised as ultra-processed. Of all items in the food lists, 36⋅1 % in the NHS and HPFS cohorts and 43⋅5 % in the GUTS cohorts were identified as ultra-processed. Future work is needed to validate this approach. Documentation and discussions of alternative approaches for categorisation are encouraged.

Ultra-processed foods and recommended intake levels of nutrients linked to non-communicable diseases in Australia: evidence from a nationally representative cross-sectional study.

OBJECTIVE: This study aimed to describe the consumption of ultra-processed foods in Australia and its association with the intake of nutrients linked to non-communicable diseases (NCDs). DESIGN: Cross-sectional study. SETTING: National Nutrition and Physical Activity Survey (2011-2012). PARTICIPANTS: 12,153 participants aged 2+ years. MAIN OUTCOME MEASURES: Average dietary content of nutrients linked to NCDs and the prevalence of intake outside levels recommended for the prevention of NCDs. DATA ANALYSIS: Food items were classified according to the NOVA system, a classification based on the nature, extent and purpose of industrial food processing. The contribution of each NOVA food group and their subgroups to total energy intake was calculated. Mean nutrient content of ultra-processed food and non-ultra-processed food fractions of the diet were compared. Across quintiles of the energy contribution of ultra-processed foods, differences in the intake of nutrients linked to NCDs as well as in the prevalence of intakes outside levels recommended for the prevention of NCDs were examined. RESULTS: Ultra-processed foods had the highest dietary contribution (42.0% of energy intake), followed by unprocessed or minimally processed foods (35.4%), processed foods (15.8%) and processed culinary ingredients (6.8%). A positive and statistically significant linear trend was found between quintiles of ultra-processed food consumption and intake levels of free sugars (standardised ß 0.43, p<0.001); total (ß 0.08, p<0.001), saturated (ß 0.18, p<0.001) and trans fats (ß 0.10, p<0.001); sodium (ß 0.21, p<0.001) and diet energy density (ß 0.41, p<0.001), while an inverse relationship was observed for dietary fibre (ß -0.21, p<0.001) and potassium (ß -0.27, p<0.001). The prevalence of non-recommended intake levels of all studied nutrients increased linearly across quintiles of ultra-processed food intake, notably from 22% to 82% for free sugars, from 6% to 11% for trans fat and from 2% to 25% for dietary energy density, from the lowest to the highest ultra-processed food quintile. CONCLUSION: The high energy contribution of ultra-processed foods impacted negatively on the intake of non-ultra-processed foods and on all nutrients linked to NCDs in Australia. Decreasing the dietary share of ultra-processed foods would substantially improve the diet quality in the country and help the population achieve recommendations on critical nutrients linked to NCDs.