{"doi":"10.20944/preprints202308.1110.v1","title":"Change in Ultra-Processed Food Consumption Moderates Clinical Trial Outcomes in Depression: A Secondary Analysis of the SMILES Randomised Controlled Trial","abstract":"Background: In this secondary analysis of the Supporting the Modification of Lifestyle In Lowered Emotional States (SMILES) randomised controlled trial, we investigated if the beneficial effects of a dietary intervention on clinical depression were driven, in part, by reducing the consumption of foods classified as ultra-processed.Methods: The SMILES trial enrolled 67 adults with major depressive disorder, randomly assigning them to either a 12-week modified Mediterranean dietary intervention or a social support control. Our analysis included 44 participants with non-missing dietary data and at least one valid Montgomery–Åsberg Depression Rating Scale (MADRS) assessment at 12 weeks of follow-up. The Nova food classification system was used to estimate the proportion of ultra-processed foods in the overall diet (percentage of grams) based on data from seven-day food diaries. We fitted linear regression models under blinded conditions to determine whether ultra-processed food intake-change from baseline to 12 weeks moderated the dietary intervention effects on depressive symptoms. We estimated mean differences in depressive symptoms along with ninety-five per cent confidence intervals (95%CIs).Results: For participants in the dietary intervention, there was an additional 2.5-point improvement in MADRS scores for each 10% reduction in the dietary share of ultra-processed foods compared to participants in the control group (between-group mean differences in depressive symptoms: −2.46, 95%CIs −4.71 to −0.20, p=0.039, η p 2 of 0.10).Conclusions: These preliminary findings suggest that the therapeutic benefit of a dietary intervention for depression may stem, at least in part, from reductions in the dietary share of ultra-processed foods.","journal":"Preprints.org","year":2023,"id":390795,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":9,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9165,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":284809,"name":"Mojtaba Lotfaliany","orcid":"0000-0001-6594-9004","position":1,"is_corresponding":false},{"id":857955,"name":"Priscila Machado","orcid":"0000-0003-4607-5094","position":2,"is_corresponding":false},{"id":109817,"name":"Felice N. Jacka","orcid":"0000-0002-9825-0328","position":3,"is_corresponding":false},{"id":284812,"name":"Mohammadreza Mohebbi","orcid":"0000-0001-9713-7211","position":4,"is_corresponding":false},{"id":109816,"name":"Adrienne O’Neil","orcid":"0000-0002-4811-5830","position":5,"is_corresponding":false},{"id":1162590,"name":"André O. Werneck","orcid":"0000-0002-9166-4376","position":6,"is_corresponding":false},{"id":593311,"name":"Carlos Augusto Monteiro","orcid":"0000-0002-3777-1533","position":7,"is_corresponding":false},{"id":36311,"name":"Amy Loughman","orcid":"0000-0002-0257-1443","position":8,"is_corresponding":false},{"id":109820,"name":"Tetyana Rocks","orcid":"0000-0002-4529-5872","position":9,"is_corresponding":false},{"id":1162591,"name":"Nikolaj Travica","orcid":"0000-0003-1841-3017","position":10,"is_corresponding":false},{"id":56340,"name":"Michael Berk","orcid":"0000-0002-5554-6946","position":11,"is_corresponding":false},{"id":921522,"name":"Rachelle Opie","orcid":"0000-0002-3816-0670","position":12,"is_corresponding":false},{"id":109819,"name":"Wolfgang Marx","orcid":"0000-0002-8556-8230","position":13,"is_corresponding":false},{"id":109812,"name":"Melissa M. Lane","orcid":"0000-0002-5739-4560","position":0,"is_corresponding":true}],"reference_count":59,"raw_metadata":null,"created_at":"2026-07-19T01:18:37.743462Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}