It is well-established that the use of appearance-focused social media is associated with eating disorder (ED) symptoms, due to the presence of idealized imagery. Of concern, social media exposure is increasingly influenced by algorithms, which recommend content based on an analysis of the users' previous patterns of engagement. However, the relationships between users' engagement with social media content based upon its centering of appearance and eating, the presence of these themes in content suggested to them, and their ED symptoms remains unknown. The current study aimed to examine these relationships in the context of TikTok, a video- and algorithm-based platform. Undergraduate students (N = 230; 78% female) completed self-report measures of ED symptoms, upwards social media appearance comparisons, as well as a novel measure of TikTok activity. Serial mediation analyses provided support for indirect relationships between engagement with appearance/eating-related content and ED symptoms via higher proportions of appearance/eating-related recommended content and higher levels of upwards social media appearance comparisons, respectively. There was no association between average screen time, nor general tendency to actively engage with content, and either ED symptoms or upwards social media appearance comparisons. Findings provide preliminary support for how engagement on TikTok is related to targeted exposure in ways that may contribute to perpetuating and exacerbating ED symptoms. Social media use has been consistently associated with greater eating disorder symptoms. However, the ways in which users' engagement with social media content may be related to targeted social media exposure, and in turn eating disorder symptoms, remains unknown. This research provided preliminary evidence for associations between users' engagement with, and targeted exposure to, TikTok content related to appearance and eating, and their eating disorder symptoms.