What adolescents see on Instagram: Content analysis of #intermittentfasting, #keto, and #lowcarb.

Aim: To describe popular diet content visible on #intermittentfasting, #keto, and #lowcarb on adolescent social media accounts.

Methods: An adolescent Instagram profile captured 200 'top' images from three popular diet hashtags (#intermittentfasting, #keto, and #lowcarb) across two timepoints. Images were coded using a pre-determined ontology as food (core or discretionary; common foods/food groups), people (group, individual, before/after), or informative. Descriptive statistics were used to summarise these categories across hashtags.

Results: At the time of first data collection, there were 3.8 million #intermittentfasting, 19 million #keto, and 22 million #lowcarb posts on Instagram. At the second timepoint there were 4.3 million #intermittentfasting, 21.5 million #keto, and 24.3 million #lowcarb posts. Images tagged #intermittentfasting were categorised as 44% food, 39% people, 10% information; #keto were 64% food, 28% people, 5% information; and #lowcarb were 69% food, 14% people, 16% information. Food images mostly depicted animal proteins (58.6% of #intermittentfasting; 62.9% of #keto; and 40.1% of #lowcarb). Images of people were individual (44%) or before/after (39%); mostly female (77%), of white (53%) ethnicity. Across all posts, 12.5% were linked to a commercial product/program, and 2.3% provided nutrition information.

Conclusion: Diet-related images visible when adolescents search #intermittentfasting, #keto, and #lowcarb on Instagram promote animal-based foods with or without vegetables. These diet hashtags on Instagram do not provide nutrition information and are not helpful for young people searching for diet information online.