We found that among Chilean children and adolescents, eating during screen time was very common (more than 85% of sample reporting screen time consumption), and that children consumed a notable proportion of their daily calories while watching a screen (34.7% and 42.3 % of daily energy intake for children and adolescents, respectively). When comparing eating occasions consumed on-screen versus off-screen, there were no consistent differences in the nutrient profile or food groups consumed for either age group. However, our daily consumption analyses revealed that higher weekly hours of TV viewing was associated with elements of a less healthy diet including more sweets and desserts in children, and more sugar sweetened beverages in adolescents.
Overall TV viewing was lower than in other Latin American countries such as Brazil  and Mexico  and much lower than the US. In the US, for example, the average TV viewing time was close to 2.5 hours/day, but when other forms of media use were taken into account, the total amount of screen time was between 5 and 12 hours/day depending on age group . Nevertheless, screen time in Chile (~ 2h and 2.5 h, for children and adolescents, just in TV viewing) surpasses recommendations to limit screen time use to 1 hour/day  in children 2-5 years and <2 hours/day  for children and teens 5 to 17 years.
Despite lower screen time, eating during screen time was more common and contributed to a higher proportion of total daily calories in Chile compared to the United States. Specifically, one study conducted in a small US sample found that kids consumed 20-25% of daily energy intake during TV viewing, compared to 36-43% in this study. These differences between both studies could be due to study setting (place and year) as well as in how screen time consumption was defined. Over 70% of our sample reported at least one main meal in front of a screen, which is similar to a recent UK study , but higher than in Brazil (~60%)  and Canada (~30%) . The eating occasions most frequently consumed while viewing a screen in our sample were breakfast and once, in children, and dinner and once for adolescents. Once, a Chilean meal typically consisting of bread and an assortment of fixings (such as jam, butter, avocado and cheese) might in some cases replace dinner. Our results are similar to what was found in the US  and in Mexico  in which dinner and snacks were most frequently consumed while on a screen.
The high proportion of calories and eating occasions consumed while on a screen in our sample is of concern, given previous research linking poor diet quality to screen time consumption  . However, in our study, we did not find a large, consistent association between eating during screen time and nutritional quality (as measured by % of calories from critical nutrients or by more- or less- healthy food groups) when we examined this relationship at the eating occasion level. For children, at the eating occasion level, on-screen meals were associated with a higher percent of energy from total sugar, but the opposite was found for snacks. At meals consumed during a screen, children were more likely to consume breakfast cereals, desserts/sweets, and milk and yogurt than off-screen, which could be a reflection of the fact that breakfast was the most commonly meal consumed on-screen. Surprisingly, sugary drinks were actually less likely to be consumed during snacks consumed while viewing a screen. Meanwhile, adolescents, there were only trivial differences in the nutritional profile for on vs. off screen snacks and meals, with similarly small differences found for food groups consumed.
These mixed results were further reflected when we analyzed the association between overall eating during screen time and total daily intake. Children who consumed the most calories on-screen consumed a higher percent of sugar and less fruit. However, adolescents who consumed the most calories on-screen consumed fewer total calories, a lower percentage of saturated fat, and less sweets and desserts, and fruit. Although somewhat surprising, previous studies have also reported mixed findings. For example, while one recent study found that children who watched TV during meals consumed on average 6% more energy from ultra-processed foods, compared to those who did not , another study  did not find significant associations between increased TV viewing at meals and overall diet quality.
When we examined the relationship between overall TV viewing and diet, we found more consistent associations between higher TV viewing and poorer dietary quality, although the differences remained relatively small. For example, we found that children watching more TV consumed more sweets and desserts, and adolescents with higher TV viewing consumed more SSBs, and milks and yogurts. While there was also a tendency towards lesser consumption of fruits with higher reported TV viewing, the differences were not statistically significant. One explanation for our observed associations is that there might be unmeasured characteristics that are related to screen time, such as parenting style, which also might drive or affect children’s dietary behaviors. For example, parental self-efficacy to limit screen time has been associated with children’s screen time , and it could also be related to self-efficacy of other family dietary behaviors.
A second, and likely more important aspect to consider is TV food and beverage advertising. Children and adolescents are exposed to unhealthy food marketing around the globe [50, 51]. Across different countries, the products that are advertised tend to be high in energy, saturated fats, sugars, and sodium, and be of little nutritional value [34, 52, 53]. Unhealthy food and beverage marketing affects children’s food preferences, choice and consumption [54-57] of advertised products, and in Chile, products commonly advertised on TV during the same time period than when our data collection took place included sodas and sweet desserts (cookies, chocolate, candies, and bakery) . Our results suggest that the increase in consumption of advertised products might not necessarily be during screen time itself, but at other times of the day (at least for adolescents), since we did not observe a consistent increased likelihood of consumption of typically advertised products during screen time. For example, in adolescents, sweets and desserts, and SSBs were as likely to be consumed at meals with or without screens. In addition, product placement, a form of marketing, might also be influencing dietary choices. For example, beverages are commonly portrayed in TV shows preferred by adolescents, which might affect norms regarding their desirability  and latter consumption.
If we believe that food marketing might be the major driver of some of the associations observed, then our results suggest that discouraging overall screen time as a behavior might be more important than discouraging consumption during screen time itself; indeed, the two were not well correlated and it was only overall screen time that was linked with poor diet. Also, our results highlight the importance of understanding how the implementation of the Chilean Law of Labelling and Marketing, which restricted child-targeted food and beverage marketing of products exceeding certain nutrient thresholds , might have shifted both children’s exposure to TV advertising and their dietary intake.
Further research will also be needed to understand the relationship between non-TV screen time, eating behaviors, and dietary intake. Most of the research conducted to date has focused on TV viewing as the main form of screen time. However, child-directed TV supply, as well as the consumption of TV media has dropped in Chile over the past 3 years , with 2018 representing an all-time low in the average time on TV among children and adolescents. Furthermore, adolescents are the age group that most frequently reports use of TV via internet or streaming. Because research has shown that unhealthy food ads predominate in content on digital platforms such as YouTube [61, 62] Facebook  and Instagram , an area for future research is understanding how other forms of screen time (not only TV viewing) are related to diet, given the potential effects of unhealthy food marketing on these platforms.
TV viewing and other forms of screen time have been defined as sedentary behaviors , and screen time can lead to weight gain by affecting the energy balance equation towards less calorie expenditure, among other pathways. However, physical activity, sedentary behaviors and diet cluster together in complex ways, with healthy and unhealthy behaviors co-occurring , and it is possible for a child to be physically active, but at the same time have high levels of screen time. For our study, we lacked data on physical activity, but it would have been interesting to assess how this behavior was associated with levels of screen time, an important pathway in the screen time-obesity relationship.
Our study has several limitations. Because of questionnaire design and data available for the study, we were unable to distinguish between the eating that might have occurred with use of different devices (tablets, smartphones, computers, TVs, for example) and with different types of activities (video gaming, video watching, social media). It is possible that the relationship between screen time and dietary intake also depends on the type of device and activity. Second, our study sample was recruited from Southeastern Santiago, potentially limiting generalizability. However, 92% of Chilean children and adolescents (1st-8th grade) attend public funded schools , as does our sample, and we therefore believe that our sample is to an extent characteristic of this age group in Chile. Thirdly, as with any dietary study, our results are subject to the possibility of misreporting. In particular, the parents/caregivers of our younger participants might not have been aware of all foods consumed by the child, in particular during the school day, and even though we attempted to complement our information with the use of school lunch menus, it is always possible that the information is incomplete. Finally, the dietary intake was from a one-day period, which might not be representative of children and adolescents’ usual food consumption, nor of their typical screen time eating behaviors.
Despite these limitations, several strengths are important to mention. First, our data enabled us to assess not only the behavior of eating during screen time, but also, how overall TV viewing relates to dietary intake. This allowed us to gain insights on the relative associations of each behavior, and whether behavioral interventions and recommendations should focus on discouraging one behavior versus the other. Second, our eating occasions analysis included a substantial sample, allowing us to compare on- versus off-screen time consumption with more level of detail than other studies have done. Furthermore, unlike other studies that also focused on the eating occasion level [21, 22], we did not restrict our analyses to main meals, but also captured snacks, providing a more complete picture of the associations of interest.