Socioeconomic and Racial/Ethnic Inequalities in Exposure to Ultra-Processed Food and Sugar-Sweetened Beverage Marketing: A Systematic Review

Background: The commercial determinants of health (CDoH) play a critical role in driving non-communicable diseases through the promotion of ultra-processed foods (UPFs) and sugar-sweetened beverages (SSBs). However, commercial food marketing strategies do not affect all populations equally. Objective: This protocol outlines the methodology for a systematic review aimed at investigating how socioeconomic and racial/ethnic inequalities relate to exposure to UPF and SSB marketing, and how this exposure articulates with food choices and health outcomes in socially vulnerable populations. Methods: Guided by the PRISMA 2020 and PRISMA-Equity guidelines, comprehensive searches were conducted across five electronic databases: PubMed/MEDLINE, Web of Science, Scopus, LILACS, and APA PsycINFO. Eligibility criteria include primary empirical studies (quantitative, qualitative, and mixed-methods) assessing UPF and SSB marketing exposure stratified by socioeconomic position and/or race/ethnicity according to the PROGRESS-Plus framework. Study selection and duplicate removal were managed using Rayyan software by two independent reviewers. Quality assessment of included studies was performed using the Mixed Methods Appraisal Tool (MMAT, version 2018). Due to methodological heterogeneity, a thematic narrative synthesis was implemented, structured around five core exposure domains: targeted marketing and cultural segmentation, psychosocial mechanisms, visual commercial pollution (outdoor/OOH), retail choice architecture, and digital ecosystems. Keywords: Ultra-processed foods; Sugar-sweetened beverages; Food marketing; Health equities; Socioeconomic factors; Racial/ethnic disparities; Commercial determinants of health; PROGRESS-Plus; Systematic review.