Energy drinks (EDs) are non-alcoholic functional beverages with a stimulating effect, intended for adults subjected to increased mental and/or physical stress [1]. These drinks are often advertised as reducing fatigue, improving concentration, and providing energy. EDs should not be confused with isotonic drinks, which are designed to replenish water and electrolytes lost in sweat to maintain proper hydration, as well as to provide small amounts of carbohydrates to refuel during and after exercise [2]. In contrast, a characteristic feature of EDs is their high caffeine content (>150 mg/L), which is not present in isotonic drinks. Other substances which can be found in EDs include taurine, glucuronolactone, B vitamins, L-carnitine, sucrose, minerals and herbal supplements such as ginseng, guarana, yerba mate, cocoa, kola nut, and ginkgo biloba [3]. The effects of caffeine, a crucial ingredient of EDs, on the human body are mediated by several mechanisms, including: antagonism of adenosine receptors, inhibition of phosphodiesterase, intracellular mobilization of calcium ions, and antagonism of benzodiazepine receptors. Due to the caffeine content, EDs may provide beneficial effects such as improved psychomotor performance (reaction time, memory, concentration) [4, 5]. Simultaneously, caffeine increases heart rate, dilates blood vessels, and increases thermogenesis and lipolysis [6].

Caffeine is considered well studied in terms of exercise performance. In studies on both professional athletes and amateurs, its effectiveness has been demonstrated by enhanced aerobic endurance and its ergogenic effects on cognitive function [7]. As stated in the recently published position stand by the International Society of Sports Nutrition (ISSN), EDs can also enhance acute aerobic exercise performance [8]. Nevertheless, according to the above-mentioned position stand, EDs are not recommended for children (aged 2–12 years old) in relation to physical exercise. Adolescents who consider drinking EDs around training should exercise caution and ask for parental guidance due to insufficient data on caffeine safety in this population. While the effects of caffeine have been extensively studied in adults, with both positive and negative outcomes observed depending on dosage, genotype, and other factors, conducting similar experimental studies in children poses ethical challenges. According to our knowledge, so far, only one such study has been performed [9]. Given that EDs are relatively recent products on the market, the long-term consequences of their regular consumption remain poorly understood. Observational studies conducted among children and adolescents have limitations that prevent the confirmation of definite cause-and-effect relationships. Therefore, due to the lack of sufficient data on the relationship between caffeine intake and health outcomes in the paediatric population, experts from the European Food Safety Authority (EFSA) have yet to determine a safe daily dose of caffeine for children [10].

Childhood and adolescence are critical periods for brain development, particularly in processes such as myelination of white matter and changes in grey matter volume, which reaches its adult size between ages 20 and 25. EDs are suspected of potentially causing damage in these areas of the brain [11]. Consumption of EDs among children and adolescents may increase the risk of cardiovascular, neurological, psychiatric, gastrointestinal, metabolic, and other disorders [12–14]. Adolescents who regularly consume EDs have reported higher frequency of stress, nervousness, anxiety, and depression symptoms [15, 16]. In teenagers, aside from the potentially direct impact of stimulants on brain function, it has been demonstrated that these substances affect sleep duration and quality. Adolescents who frequently consumed caffeine-containing beverages were more likely to not meet the recommended sleep duration guidelines [17–20], including experiencing insomnia [21, 22]. However, it is not only the high caffeine content in EDs that may be associated with negative health outcomes. It should also be emphasized that EDs contain a high amount of sugar, which can negatively impact oral health—a concern that is already prevalent among children and adolescents in Poland [23]. Regular consumption of such beverages may also contribute to an excessive energy intake, leading to the development of overweight and obesity, along with all the associated health consequences [24]. This is supported by research findings indicating that ED consumption among adolescents was associated with a higher body mass index [25].

Considering the above reports, it may be surprising that the marketing of EDs is aimed not only at people involved in sports and esports, but also at children and adolescents using advertising strategies that appeal to their interests, lifestyles, and social circles [26]. By sponsoring popular events such as skateboarding, snowboarding, and gaming tournaments, ED companies align their brands with activities that resonate with younger demographics. These events often attract young people who are passionate about action sports or gaming culture, creating a direct connection between the brand and their interests. Many countries have already implemented legal measures aimed at limiting the consumption of EDs among children and adolescents. In Sweden, Denmark, Argentina, and as of January 2024, also in Poland, there are restrictions on the sale of EDs to underaged persons, similar to those applied to alcohol sales. Other actions include additional taxation affecting product pricing, bans on sales in schools, and specific guidelines regarding packaging and labelling [27].

In order to understand why adolescents consume EDs, it is crucial to identify the driving factors. Despite national discussions, there is a lack of systematic, up-to-date data regarding this problem among Polish youth, with details on consumption patterns evolving over time. This study aimed to analyse the consumption of EDs and the motives for their consumption among adolescents involved in sports in Poland.

In the present study we found that nearly half (46.4%) of the participants aged 10–14 years were ED consumers. These results are different from those published in 2013 by EFSA experts, who found that 73% of teenagers in Poland consumed EDs [10]. This discrepancy may be due to the fact that Zucconi et al. (2013) included adolescents aged 10–18 in their study group, while in this study subjects up to 14 years of age were examined. At the same time, the results of our study showed that the frequency of consuming EDs increased with age, which was consistent with the results of others [33]. It can also be assumed that the consumption of EDs has changed over the last 10 years, but the study by Zucconi et al. was the only one available which was conducted on a large sample (4,368) and used a validated tool. Results more similar to ours come from the 2021 National Study on the Diet and Nutritional Status of the Polish population, on a representative sample: EDs were consumed by 35.7% of boys and 27.4% of girls aged 10–17 [34]. However, it should be noted that this study assessed the overall diet, so the question about EDs was one of many, which could affect the accuracy of the data obtained, and the age range of the subjects was wider. It is also worth mentioning the results of the multi-centre project Health Behaviour in School-aged Children (HBSC), conducted, among other countries, in Poland [35]. In 2022, in a representative sample of 5,395 children aged 11, 13, and 15, the percentage of ED consumers was 46.7%, which closely aligns with our findings. According to other studies conducted in Poland in recent years, the percentage of adolescent ED consumers varied in different regions of the country: from 54% in Lublin province [29] to 89% in Subcarpathia and Lesser Poland provinces [28]. In our study, we aimed to present data on ED consumption by province; however, due to the small sample sizes within individual provinces, we decided to present the results for the entire group as a whole. Compared to global data, the percentage of subjects classified as ED consumers in this study seems relatively low: in the United States, 64.3% of teenagers aged 13–17 reported occasional consumption of energy drinks [36], while in Canada 62% did so (among students aged 12–18 years) [37]. Based on the results published by Nuss et al. [38], who studied ED consumption among Australian adolescents it can be concluded that more Polish than Australian students (aged 12–17 years, mean age 14.7 years) used EDs (46% vs. 24%). According to the previously mentioned EFSA report [10], which included data from a total of 52,000 inhabitants of the European Union, 68% of teenagers used EDs – ranging from 48% in Greece to 82% in the Czech Republic. While discussing the popularity of EDs among adolescents according to different authors, some discrepancies in the findings occur, probably due to methodological differences between studies in terms of defining an ED consumer. In the present study we decided to adopt a broad definition, as we included both individuals with daily consumption of ED and those who consumed them once a month or less often. A similar definition was also applied in the EFSA report [10]. Another potential explanation for the lower percentage of ED consumers in our study compared to others may be the age of studied subjects – in the present study we focused on 10–14-year-olds, while most other authors included older students up to 18 years of age. This is important because, as shown in our and other studies [39], ED consumption increased with age.

Male participants in our study were more likely to drink EDs than female participants (53.0% vs. 47.0%), which was in line with other studies conducted in Poland [28, 29], as well as in other countries such as Norway [40], Slovakia [33, 41] and Germany [42]. In the above-mentioned HBSC study regarding Polish youth, the frequency of EDs consumption among girls and boys reporting daily consumption of EDs was similar (7.8% and 6.5%, respectively) [35]. However, it should be emphasized that this study compared groups consuming EDs every day. Notwithstanding, future research should not omit girls, especially considering the results indicating that the increase in popularity of EDs in 2018 compared to 2014 was more pronounced in the group of girls than boys [39].

Consistent with previous studies from Poland [30], we did not find any differences in ED consumption among adolescents living in urban and rural areas. This contrasts with the study by Błaszczyk-Bębenek et al. [28], which detected higher ED consumption among children and adolescents living in bigger cities compared to those living in smaller cities.

The average daily caffeine intake from EDs among consumers in our study was 20.8 ± 81.2 mg, which was twice as high compared to a study from India, where 300 adolescents were surveyed [43]. The authors did not observe any differences in caffeine consumption between boys and girls; however, in our study, boys consumed significantly more caffeine from EDs than girls. In a study of the Polish population [44], it was found that the average daily caffeine intake from EDs was 14.31 ± 43.96 mg; it should be emphasized, however, that the majority of participants were adults. In contrast, in the study by Jia et al. [45], the average daily caffeine intake from all sources among consumers of caffeine-containing snacks aged 6–17 years was 21.6 mg. However, the main sources of caffeine were tea and coffee, while energy drinks and other carbonated beverages ranked third, providing 15% of the total caffeine intake. In the Korean population aged 15–18 years, caffeine intake from all sources was estimated at 30 mg per day, and the contribution of EDs to overall caffeine intake in the entire population was estimated at 0.8% [46]. It is important to emphasize that in our study, we assessed caffeine intake exclusively from EDs, and therefore the relatively high values obtained are particularly concerning.

Our results indicate that good taste was the most common motive for consumption among all age groups of ED consumers, except for 14-year-olds. Only 14-year-olds most often stated that the motive for drinking EDs was “the need for energy.” In general we observed a tendency for motives such as “need for energy” or “need to stay awake” to become more popular with age. This implies the need to include older age groups in future research as consumption motives seem to change, probably due to increasing expectations and requirements at school and from the peer environment. Other cross-sectional studies have also demonstrated this growing trend concerning the “need to stay awake” motive [10]. From the gender perspective, girls were more likely than boys to report using EDs to stay awake and to improve concentration during studying. The desire to stay awake may be connected with the fact that sleep disturbances seem more common among adolescent girls than boys [47]. Although we did not study the aspect of sleep quality, our results may suggest that the proper sleep pattern in girls could have been disturbed by drinking EDs: after using EDs during the day, problems with falling asleep might be more likely to occur, and caffeine may lower sleep quality [48]. After a night which did not bring the expected rest, drinking EDs on the following day is aimed at eliminating fatigue and maintaining concentration at school, and the cycle repeats. The message sent from educational campaigns and parents and teachers to children should clearly indicate that fatigue ought to be interpreted as a signal to rest.

Although other motives were chosen less frequently, attention should also be paid to children using EDs to improve physical performance during training (from 1.8% to 9.6% in various age groups in the present study). According to the previously cited position of the ISSN [8], EDs are not recommended for physically active adolescents under 12 years of age. ED use under parental supervision may be considered in those above this age. Our study did not assess the level of parental control, although it can be assumed that it varies greatly depending on the case, because not all parents are duly interested in the nutritional choices of their children [49]. The frequent consumption of EDs at home observed in our study may corroborate this.

As regards the circumstances of ED consumption, respondents, regardless of age, reported drinking them mainly with friends (46.3%) and at home (30.1%), less often at school (9.4%) and during training or recreational physical activity (8.6%). Even though these results are similar to those of other authors, it is difficult to compare them due to slightly different answer options. German adolescents (aged 9–19 years, mean age 13.1 years) used EDs mainly during parties (59%), and nearly 8% reported also drinking EDs while working out [42], which is in line with our results. A higher percentage (14.6%) of adolescents drinking EDs in the context of physical activity was found in the Spanish population [50]. It is worth mentioning that consuming meals and drinks, aside from their nutritional function, also serves a social function. For young people, the need to belong to a group is more important than for adults, so it can be assumed that the consumption of EDs by peers may encourage others to drink these beverages [51]. Another disturbing aspect is the low level of knowledge of young people about EDs: in our study, over 40% of total participants had problems distinguishing an isotonic drink from an ED. Other authors also have highlighted the problem of insufficient knowledge. For example, in the study by Kwiatkowska et al. [29], only 6% of respondents were aware that EDs may be harmful to young people. This is particularly alarming given that it has been shown in observational studies that excessive consumption may result in tachycardia, vomiting, cardiac arrhythmias, seizures, disrupted sleep patterns and even physiological dependence [52].