Lane, M.M.; Lotfaliany, M.; Machado, P.; Jacka, F.N.; Mohebbi, M.; O’Neil, A.; Werneck, A.O.; Monteiro, C.; Loughman, A.; Rocks, T.; Travica, N.; Berk, M.; Opie, R.S.; Marx, W. Change in Ultra-Processed Food Consumption Moderates Clinical Trial Outcomes in Depression: A Secondary Analysis of the SMILES Randomised Controlled Trial. Preprints2023, 2023081110. https://doi.org/10.20944/preprints202308.1110.v1
Lane, M.M., Lotfaliany, M., Machado, P., Jacka, F.N., Mohebbi, M., O’Neil, A., Werneck, A.O., Monteiro, C., Loughman, A., Rocks, T., Travica, N., Berk, M., Opie, R.S., & Marx, W. (2023). Change in Ultra-Processed Food Consumption Moderates Clinical Trial Outcomes in Depression: A Secondary Analysis of the SMILES Randomised Controlled Trial. Preprints. https://doi.org/10.20944/preprints202308.1110.v1
Lane, M.M., Rachelle S Opie and Wolfgang Marx. 2023 "Change in Ultra-Processed Food Consumption Moderates Clinical Trial Outcomes in Depression: A Secondary Analysis of the SMILES Randomised Controlled Trial" Preprints. https://doi.org/10.20944/preprints202308.1110.v1
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, ηp2 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.
ultra-processed food; Nova food classification system; major depressive disorder; nutritional psychiatry; secondary analysis; randomised controlled trial
Medicine and Pharmacology, Psychiatry and Mental Health
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