Table A1.

Coding items.

	Coding Items	Description
1	Ad title	Ad title on YouTube
2	Product name	The name of the product that the ad mainly shows
3	Name of functional ingredient (s)	The name of the ingredient(s) involved from the Consumer Affairs Agency database for the product(s) featured in the video ad
4	Length of the ad	Number of seconds the video lasts
5	Release date	Release date shown on YouTube
6	Number of views	Number of times the video ad was viewed on YouTube. The average number of views per month was calculated (rounded to one decimal place) to remove the effect of the release date
7	Meaning of “fat” in the labeling	“Approved labeling content” or “intended functionality” of the products appearing in the video ad from the Consumer Affairs Agency database. The first author inductively classified the meaning of “fat”
8	Type of product	Foods for Specified Health Uses (FOSHU) or Foods with Function Claims (FFC)
9	Business name	“Applicant’s name” or “Notifier’s name” of the product that mainly appears in the video ad from the Consumer Affairs Agency database
10	Body type of the main character (obese/standard/thin)	Body mass index of ≤18.5 was considered thin, BMI of ≥25 was considered obese, and other values were considered standard [65]
11	Main character gender	The first author guessed the main character’s gender as male or female
12	Main character age	The first author guessed the main character’s apparent age in 10-year increments (e.g., 20 s, 60 s)
13	Type of endorser [66]	The first author recorded the type of endorser of the main character, if the name or title of the performer was shown in the title or summary field of the video ad (e.g., celebrity, typical consumer, anonymous spokesperson)
14	Presence or absence of food	If food or dishes other than the product appeared in the video or non-verbal content, it was coded as (1)
15	Food appearance time ratio	Number of seconds in which food appeared as non-verbal images/number of seconds in video (e.g., if food or dishes appeared for 7 s out of a 10-s video, the ratio was 0.7)
16	Presence or absence of depiction of physical activity of ≥3 METs	If physical activity of ≥3 METs appeared as non-verbal and visual content, referring to the Physical Activity Standard 2013, it was coded as (1) [67,68]
17	Presence or absence of positive depiction of physical activity of ≥3 METs	If there was a non-verbal/visual description of physical activity of ≥3 METs caried out in a cheerful and joyful manner, it was coded as (1)
18	Physical activity of 3 METs appearance time ratio	Number of seconds in which physical activity of ≥3 METs appeared to number of seconds of non-verbal images in the video