Theme and sentiment of posts in a weight loss subreddit predict popularity, engagement, and users' weight loss: a computational approach.

This article examines how thematic content and sentiment in user-generated posts on the subreddit r/loseit, an online weight loss community, relate to users' self-reported weight loss outcomes. Through computational analysis of 21,154 posts over ten months, the study identified 28 distinct weight-related topics and found that posts about goal setting and progress significantly predicted greater weight loss, especially when these posts received higher engagement measured by upvotes and comments. Positive sentiments in posts were associated with higher post scores (popularity), while negative sentiments correlated with increased comment activity (engagement). The findings suggest that public commitment and social interaction within online support groups may enhance self-regulation and motivation for weight loss, offering implications for designing social media-based health interventions.