A study published in The Journal of Nutrition, revealed that duration of smartphone usage and content type are associated with unhealthful dietary intakes among adolescents.

Traditional screen time such as television watching is an important factor that influences dietary behaviors and obesity risk in adolescents. Because smartphones, compared with television and computers, allow easier access to a wider range of content regardless of time and location, smartphones are likely to have a strong influence on adolescent dietary practices. To better understand the impact of smartphone usage patterns (duration and content type) with dietary risk factors among adolescent smartphone users, researcher Hannah Oh (Korea University) and colleagues conducted a cross-sectional analysis using a nationally representative sample of 54,601 middle- and high-school students in the Korea Youth Risk Behavior Web-Based Survey 2017.

Girls and boys, between 12 – 18 years of age, completed an online-based questionnaire that assessed smartphone use (average duration and most frequently used content type) and dietary risk factors that have previously been shown to be associated with obesity, cardiovascular disease, diabetes, and certain cancers.  Participants were asked to report the average duration of weekday and weekend smartphone use and most frequently used smartphone content type.  Smartphone content type was collapsed into 7 groups: education/information search, messenger/e-mail, social networking service/forum, game, movie/video/music, Webtoon/Web-novel, and shopping/ others, during the past 30 days. Using this information, average daily duration of smartphone use was calculated. The frequency of breakfast eating and the frequency of intakes for each food group (fruits and vegetables, Korean instant noodles, fast food, chips/crackers, and sugar-sweetened beverages) during the past 7 days was reported.

Prolonged smartphone use, >300 min/day compared with 1-59 min/day, was associated with higher prevalence of all dietary risk factors except frequent intake of chips/crackers. For most dietary risk factors, the associations became statistically significant at > 120 min/day of smart phone use. Using smartphones mainly for messenger/e-mail, social networking service/form, and games was associated with less frequent intakes of fruits and vegetables compared to those using smartphones for education/information search.  Using smartphones mainly for messenger/e-mail and social networking service/form were also associated with more frequent intake of sugar-sweetened beverages.

Food manufacturers and marketing companies of today utilize digital platforms such as social media (e.g., Facebook, Twitter) and content-sharing platforms (e.g., YouTube) to reach young people. Prolonged smartphone users are more likely to be exposed to food advertisements and marketing contents, exposed to misleading messages and creating misperceptions of foods. Some advertisements are disguised within various digital media contents, including games, videos, and blogs shared by friends and social media influencers, promoting indiscriminate exposures to unhealthy food marketing.

The authors concluded that, given the intensified use of smartphones in adolescents, more efforts should be taken to provide appropriate guidance for developing healthful smartphone usage behaviors and to introduce restrictions on unhealthy food marketing that targets young children and adolescents in digital space.


Seaun Ryu, Hajin Jang, Hannah Oh, Smartphone Usage Patterns and Dietary Risk Factors in Adolescents, The Journal of Nutrition, Volume 152, Issue 9, September 2022, Pages 2109–2116, https://doi.org/10.1093/jn/nxac098.

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