Energy drinks are nonalcoholic beverages that contain caffeine, nonnutritive bioactive substances (such as taurine, and guarana), vitamins, and sugar [1]. Caffeine and bioactive ingredients in energy drinks stimulate the brain and nervous system and support the development and function of skeletal muscle and nervous system, temporarily improving cognitive and physical performance [1]. Thus, energy drinks are marketed as focus and endurance enhancers and fatigue relievers and are often confused with functional beverages. However, energy drink is a new category of beverages that is different from these beverages [1,2].

Energy drinks have been marketed in more than 165 countries since it was first launched in Austria in 1987 [2,3]. It has gained popularity, especially among the young population, and its annual growth rate is the fastest in the global beverage market. This expansion of the energy drink market is expected to continue [4]. In Korea, “Bacchus,” a Korean-style energy drink, was launched in 1963, and “Hot6,” ‘Red Bull,” and “Monster Energy” were introduced in the early 2010s. Sales of energy drinks in the domestic market, which have gradually increased since their introduction, have recently surged [5,6].

There is growing evidence addressing the adverse health effects of energy drink consumption; both acute and chronic energy drink consumption is related to cardiovascular symptoms (e.g., fast heartbeat, increased blood pressure), sleep impairment (e.g., insomnia, sleep dissatisfaction), nervousness and gastrointestinal symptoms (including stomachaches, headache, irritation), and mental and metabolic health (including anxiety, depressive symptoms, obesity, and type 2 diabetes) [1,7-9]. Moreover, energy drink consumption is associated with an unhealthy lifestyle (such as poor dietary habits, sedentary lifestyle) and is implicated as a trigger for substance use (such as tobacco, alcohol, drugs) and other risk behaviors (such as gambling, screen addiction, violence, driving while intoxicated) [10-12]. Previous studies have revealed that the prevalence of energy drink consumption is the highest among adolescents [1,10]. A 2011 study by the European Food Safety Authority revealed that energy drink consumption in adolescents was more than twice as high as that in adults. In the same year, the American Academy of Pediatrics raised significant concerns about the potential health risks related to energy drink consumption in adolescents [13].

However, little is known about the prevalence and trend of energy drink consumption among Korean adolescents and the factors associated with energy drink consumption. Thus, this study aimed to examine the recent trends in energy drink consumption among Korean adolescents and investigate the association between energy drink consumption and sociodemographic and individual factors.

Table 1 shows the distribution of general characteristics of the total study population, including sex, age, school grade, region of residence, subjective economic status, cohabitation with family, and academic achievement. Among a total of 325,210 participants, 52.1% were boys and the mean age was 15.1 years. There were no differences in the proportion of sex, school grade, and cohabitating with family (all P>0.05), whereas the mean age slightly increased within the study period (P=0.014).

The present study found that the prevalence of energy drink consumption (3 or more times during the past 7 days) in Korean adolescents increased substantially, nearly quadrupling from 3.2% in 2014 to 12.2% in 2019. This upward trend persisted regardless of sex, school grade, region of residence, subjective economic status, family cohabitation status, and academic achievement. The likelihood of energy drink consumption varied with sociodemographic and individual factors. In 2019, higher energy drink consumption among middle school students was associated with sex (boys), low economic status, not living with families, and low academic achievement; however, higher energy drink consumption among high school students was associated with city-dwelling, high economic status, not living with families, and high academic achievement.

Previous studies on energy drink consumption among adolescents have mainly been conducted in Australasia, North America, and Europe, where energy drink sales are markedly higher [16]. Issues with energy drink consumption have been reported using several definitions, including lifetime [3,17,18], past 30-day [18,19], past 7-day consumption [11,13,20,21], and frequent use (>20 days during the past 30 days or 4–5 or more days per week) [3]. In Australia, approximately half of the adolescents reported having ever consumed energy drinks [17]. The lifetime prevalence of energy drink consumption among adolescents in Germany, the United States,Italy, and Canada ranged from 61.7% to 73.8% [3,18,22,23].

In the United States, analysis of data from the Youth Risk Behavior Surveillance System [20] revealed a high prevalence of energy drink consumption among adolescents, with 52.3% reporting energy drink consumption over the past 7 days. The prevalence of past 7-day energy drink consumption among Korean adolescents (estimated as 30.9% in KYRBS 2019, data not shown) is lower than that in American adolescents, but higher than that in Finnish adolescents [13].

The global popularity of energy drinks among adolescents and young adults has not stopped. The prevalence of energy drink consumption worldwide has been reported to consistently increase in previous studies, regardless of the survey method or definition [3,13,20,24]. This continuous increase in energy drink consumption can be estimated from trends in the energy drinks sales market. The global energy drink market had grown approximately thrice between 2004 and 201325) and energy drink sales increased more than 30% between 2014 and 2019 [4]. Sales are still remarkably high in North America, Australasia, and Western Europe, and Asia’s energy drink market is relatively small [4,16,25]. However, sales in Asian countries are projected to lead the global energy drink market because Asian countries have the fastest growth rates [16,25]. South Korea’s domestic energy drink market has been growing steadily at an average annual rate of 6% since 2015, followed by concerns over the trend of consumption growth [6].

The present study found that energy drink consumption among Korean adolescents was more prevalent among boys and high school students after adjusting for other sociodemographic and individual characteristics. Significant sex differences in adolescent energy drink consumption were consistent with the results of previous studies [3,11,13,17-19,24,26]. Energy drinks are usually advertised as having the potential to boost energy and improve physical performance [7,26]. Compared with girls, boys are more influenced by energy drink advertisements that emphasize masculine and active images; consequently, it is estimated that boys consume more energy drinks than girls [27]. The positive association between older age and energy drink consumption during adolescence is also consistent with the results of previous studies [13,17,18,24]. This may be because older adolescents’ consumption is due to self-directed choices away from the influence of parental monitoring, or older students, who have a greater academic burden than younger ones, intentionally consume more energy drinks to compensate for sleep deprivation and continue the study [23]. Interesting findings regarding the association between energy drink consumption and academic achievement were observed. Previous studies on Finnish and German adolescents have indicated that energy drink consumption is associated with lower academic achievement and worse school performance [13,18]. Similar results were found in the total population in the present study, including middle and high school students. However, recent data revealed different aspects of the association according to the school grade. For middle school students, those with low academic achievement had a higher OR for energy drink consumption; however, for high school students, those with higher academic achievement had a higher likelihood of energy drink consumption. This seems to be because, owing to the pressure to go to college, high school students with higher school achievement habitually consume energy drinks to reduce sleep and continue studying late. In contrast, among middle school students with less study pressure, those with low academic achievement consumed more energy drinks, which is probably due to curiosity about trying energy drinks and frequent exposure to energy drink advertisements [18]. In the present study, the prevalence of energy drink consumption was slightly lower in the middle economic status group than in the high or low groups. The likelihood of energy drink consumption showed the same pattern after adjusting for sociodemographic and individual characteristics. These findings are slightly different from those of previous studies conducted in other countries, such as the United Kingdom and Belgium [11,24], which revealed that adolescents from lower-income households were more likely to consume energy drinks. In Korea, highly educated parents with high occupational status (and thus maybe parents with high income) have strong enthusiasm for their children’s education and tend to be obsessed with getting their children into top universities. Therefore, adolescents from these households may feel a greater burden of good academic scores and academic advancement and thus may habitually consume energy drinks. Some studies have observed positive effects of energy drinks on cognitive function; however, the effect was only acute and not always, and there are considerable concerns about negative effects [21,28]. Therefore, it is necessary to help adolescents and parents understand the nutritional characteristics and deleterious effects of energy drinks.

To the best of our knowledge, this is the first study to address the status and trends of and the factors associated with energy drink consumption among Korean adolescents. Our study has several strengths. The data used here were obtained from the KYRBS. Approximately 2% of all middle and high school students in Korea were selected as survey samples, and the response rate is remarkably high at >95% [14]. Moreover, although the survey was conducted at school, an anonymous web-based questionnaire was used to protect privacy and reduce the effects of social desirability bias [14]. Finally, beverage consumption varies depending on the season [29] and students’ high-caffeine drink consumption varies depending on the school exam period. Thus, it is important to check the timing of the survey, especially when studying the trends in students’ energy drink consumption. Although there have been some changes in the timing of the KYRBS since the first survey began in 2005 (e.g., the 2020-2022 survey was conducted from August to October of the year due to COVID-19), all the surveys from 2014 and 2019 were conducted in June of the year, allowing for a consistent comparison [14].

However, this study has some limitations. First, although the proportions of out-of-school adolescents among middle and high school-age adolescents are only estimated to be 0.8% and 1.7%, respectively [30], the KYRBS included only school-attending students. Thus, our findings may not be representative of all adolescents in Korea. Second, the survey collected information through self-reporting by the participants. Thus, there is a possibility of underreporting of energy drink consumption. Finally, in the KYRBS, only the frequency of energy drink consumption was surveyed, and there was no information on the understanding of energy drinks, reason for consumption, attitude toward consumption, and timing of initial consumption. Thus, no evidence could be found to help seek strategies to reduce adolescents’ energy drink consumption.

In conclusion, energy drink consumption among Korean adolescents is common, has increased recently, and varies according to sociodemographic and individual factors. Further studies are required to continuously monitor energy drink consumption patterns among adolescents, understand attitudes toward and factors influencing energy drink consumption, and develop policy and educational strategies.