[A high-risk combination: obesity, food brands, minors and challenges on YouTube]

To identify high-risk content in food advertising that combines obesogenic features with a highly emotionally engaging format.

Comparison of 304 videos (47hours and 41minutes) from 13 food brand channels (traditional advertising) and from 15 child YouTuber channels (endorsement and influence) posted in 2019. Exploratory content analysis of variables describing the communication style of the "challenges" format.

Challenges are the most common type of content (53.3%; n=162), with a greater prevalence on child YouTuber channels (59%; n=131) than on brand channels (41%; n=31).

Content created by consumers is not covered by current audiovisual communication legislation. Increased control of these practices is urgently needed, in terms of legislation, self-regulation and codes of ethics. Creativity, enjoyment or mere entertainment is not a sufficient argument for the persuasive promotion of behaviors that endanger the physical health of children.