Quality and reliability of weight management short videos on TikTok and Bilibili: cross-sectional study

Weight management has become a major focus in worldwide health, and platforms like TikTok and Bilibili are now popular for health information. However, the quality and reliability of weight management content on these platforms remain uncertain. This research systematically evaluated such videos to provide evidence-based guidance for public health communication. We analyzed the top 100 weight management videos from TikTok and Bilibili, recording their sources, content, and characteristics. The DISCERN instrument, JAMA benchmark criteria, and Global Quality Score (GQS) were used to evaluate video quality and reliability. Further analysis was conducted to explore the relationship between video quality and video characteristics. While TikTok videos attracted more likes, saves, comments, and shares, Bilibili videos were longer and exhibited higher quality and reliability (all P < 0.001). Videos from doctors and non-profit organizations had the highest DISCERN and GQS scores, while those from fitness bloggers and individual users were more popular but of lower quality. Video duration was positively associated with quality, whereas engagement indicators (likes, comments, shares, saves) were negatively associated with both GQS and DISCERN. Overall, the quality of weight management videos on TikTok and Bilibili was poor, although Bilibili performed better than TikTok. Doctors and non-profit organizations produced higher-quality content, highlighting the need for stronger platform review and greater professional contributions to improve the dissemination of reliable health information.