Although excessive sugar-sweetened beverages (SSB) intake is linked to numerous adverse health consequences, media literacy interventions rarely address the influences of food and beverage marketing with a specific focus on adults. This randomized controlled trial study investigated (1) whether media literacy education modifies adults' perceptions of SSB advertising and (2) whether changes are moderated by health literacy. Results from the multilevel mixed-effects regression analyses with the intention-to-treat last-observation-carried-forward method showed that compared to MoveMore (a matched-contact comparison condition), SIP"smart"ER (an intervention condition) participants significantly enhanced their skillsets across media literacy domains (i.e., authors/audiences, messages/meanings, representation/reality) between baseline and 6-month follow-up. Baseline health literacy status did not moderate media literacy outcomes. Both low and high health literate participants improved their outcomes, suggesting that this media literacy intervention benefited adults regardless of their health literacy level. Results demonstrate the importance of cultivating critical analyses and strengthening adults' resistance toward SSB advertising.