A scientific and regulatory review of caffeine, hydration, adolescent vulnerability, sports-related marketing exposure, and the emerging gap between restrictions on youth access and continued brand exposure in mixed-age sporting environments.
Abstract
Global consumption of energy drinks remains substantial, particularly among adolescents and young adults. These beverages are frequently associated through marketing with sport, endurance, concentration, gaming, physical performance, and active lifestyles. Scientifically, however, energy drinks and hydration beverages represent fundamentally different functional categories.
Energy drinks are water-based and therefore contribute fluid to total intake; ordinary consumption should not automatically be described as producing net dehydration. Nevertheless, their principal functional ingredient is generally caffeine, a central nervous system stimulant, rather than the water–electrolyte–carbohydrate composition used in beverages specifically formulated for rehydration during prolonged exercise.
Acute high caffeine exposure can increase urine production, particularly among caffeine-naïve individuals, while inadequate electrolyte replacement, high sugar concentrations in some formulations, large serving sizes, rapid consumption, and use during exercise or heat further limit their suitability as rehydration products.
This review examines caffeine pharmacology, hydration physiology, cardiovascular, neurological, renal and metabolic concerns, age-related susceptibility, concurrent alcohol consumption, sports marketing, and current regulatory approaches.
Particular attention is given to children and adolescents because a fixed quantity of caffeine produces a greater dose per kilogram of body weight, sleep and neurobehavioral consequences are especially important during adolescence, and leading pediatric health organizations recommend avoiding caffeinated and stimulant-containing beverages in this population.
The article also examines an important regulatory inconsistency through the case of Lithuania. Lithuania prohibits the sale or transfer of qualifying energy drinks to persons under 18 and restricts energy-drink advertising and sponsorship at events intended for minors. Nevertheless, current statutory wording does not automatically encompass mixed-age sporting events merely because 16- or 17-year-olds participate.
This creates a potential regulatory bypass through which minors who are legally prohibited from purchasing the beverage may nevertheless participate in or be exposed to highly visible energy-drink-branded sporting environments.
Keywords: energy drinks; caffeine; hydration; adolescents; sports marketing; cardiovascular risk; kidney injury; minors; sponsorship; Lithuania; public health regulation
I. Introduction
Energy drinks constitute a heterogeneous category of non-alcoholic beverages generally containing caffeine together with ingredients such as sugar or non-nutritive sweeteners, taurine, glucuronolactone, B vitamins, guarana, plant extracts and other functional ingredients.
Guarana is particularly relevant because it is itself a source of caffeine. Taurine, by contrast, should not simply be classified as another stimulant equivalent to caffeine; its biochemical actions differ substantially.
The global expansion of the category has been accompanied by intensive marketing emphasizing alertness, endurance, concentration, sport, gaming, study, nightlife and lifestyle performance.
This creates an unusual public-health situation. Unlike conventional soft drinks, energy drinks are marketed partly through their physiological effects. At the same time, unlike medicines or regulated stimulant preparations, they are sold and displayed as ordinary consumer beverages in many jurisdictions.
A further source of confusion arises from the word “energy.”
A sugar-containing energy drink does provide dietary calories and therefore metabolic energy. However, much of the immediate sensation consumers describe as an “energy boost”—greater alertness, reduced sleepiness and delayed perception of fatigue—is principally associated with caffeine-mediated central nervous system stimulation.
This distinction matters particularly in sporting environments.
A beverage capable of making a person feel more alert is not necessarily a beverage optimized to replace water and electrolytes lost through sweating.
The principal questions addressed in this review are:
- Are energy drinks appropriate beverages for routine hydration or exercise-related rehydration?
- What physiological risks are associated with caffeine-containing energy drinks?
- Why do children and adolescents require particular protection?
- How does sports marketing affect perception of these products?
- Are point-of-sale age restrictions sufficient if minors remain exposed to energy-drink branding through sporting events?
- What regulatory model would more coherently protect vulnerable consumers?
II. Energy Drinks and Hydration: Resolving the Category Confusion
2.1 Fluid Intake Is Not Equivalent to Optimal Rehydration
Because energy drinks are predominantly composed of water, consuming one contributes water to total fluid intake. It is therefore scientifically inaccurate to state that every energy drink automatically causes net dehydration.
The more relevant question is whether an energy drink is an appropriate beverage for maintaining or restoring fluid and electrolyte balance, particularly during physical exertion.
In most circumstances, the answer is no.
Water remains the principal beverage for normal daily hydration. During sufficiently prolonged or intense exercise involving significant sweating, appropriately formulated sports beverages may provide sodium, carbohydrate and fluid in proportions designed to facilitate replacement of exercise-related losses.
Energy drinks are principally formulated around stimulation rather than restoration of fluid and electrolyte balance.
2.2 Caffeine, Diuresis and Fluid Balance
Caffeine can acutely increase urine production. The magnitude of the effect depends on dose, habitual caffeine consumption and individual physiology.
Relatively high acute doses can produce more noticeable diuresis, particularly in individuals who do not habitually consume caffeine. Tolerance develops with habitual exposure, however, and moderate quantities of caffeinated beverages still contribute to total fluid intake.
Accordingly, the scientifically defensible conclusion is not:
“Energy drinks always dehydrate the consumer.”
It is:
“Energy drinks are not specifically formulated for rehydration, and substantial acute caffeine exposure can increase urine output under particular conditions.”
2.3 Energy Drinks and Sports Drinks Are Not Interchangeable
| Characteristic | Water | Sports/Hydration Drink | Conventional Energy Drink |
|---|---|---|---|
| Principal purpose | Hydration | Fluid/electrolyte replacement | Stimulation/alertness |
| Caffeine | Normally absent | Normally absent | Commonly present |
| Sodium/electrolytes | Low/variable | Specifically formulated | Often inadequate for sweat replacement |
| Carbohydrate | None | Controlled amount in many formulations | Highly variable |
| CNS stimulation | No | No | Usually yes |
| Routine hydration | Preferred | Usually unnecessary | Not preferred |
| Prolonged heavy sweating | May be sufficient depending on conditions | Potentially useful | Generally inappropriate as primary rehydration beverage |
| Children/adolescents | Appropriate | Situational | Major pediatric bodies recommend avoidance |
III. Mechanism of Action of Caffeine
3.1 Adenosine Receptor Antagonism
Caffeine acts principally as an antagonist of adenosine receptors, particularly A1 and A2A receptors.
Adenosine contributes to sleep pressure and modulation of neuronal activity. During prolonged wakefulness, adenosine signaling contributes to increasing subjective fatigue.
Caffeine occupies adenosine receptors without activating them, thereby reducing the perception of fatigue and increasing alertness.
The immediate effect is consequently best understood as pharmacological stimulation rather than production of new physiological energy.
3.2 Dose and Body Weight
A beverage containing approximately 32 mg caffeine per 100 ml provides:
- 250 ml = approximately 80 mg caffeine
- 500 ml = approximately 160 mg caffeine
For a 40 kg adolescent, 160 mg corresponds to approximately 4 mg/kg.
For a 75 kg adult, the same amount corresponds to approximately 2.1 mg/kg.
The identical container therefore produces almost twice the caffeine exposure per kilogram in the smaller consumer.
3.3 Reference Levels
| Population | Reference level |
|---|---|
| Healthy adults, single dose | Up to approximately 200 mg |
| Healthy adults, daily intake | Up to approximately 400 mg/day |
| Pregnancy | Up to approximately 200 mg/day |
| Children and adolescents | Approximately 3 mg/kg body weight/day |
EFSA reference information: European Food Safety Authority – Caffeine.
A toxicological reference level should not be interpreted as a recommendation to consume caffeine.
A multidisciplinary 2025 U.S. consensus involving the American Academy of Pediatrics, American Heart Association, American Academy of Pediatric Dentistry and Academy of Nutrition and Dietetics recommends that children and adolescents aged 5–18 avoid beverages containing caffeine and other stimulants.
IV. Health Effects
4.1 Cardiovascular Effects
Caffeine can acutely influence cardiovascular physiology.
Reported responses associated with energy-drink consumption include:
- increased blood pressure;
- palpitations;
- changes in heart rate;
- sympathetic activation;
- rhythm disturbances in susceptible individuals.
Risk varies according to individual susceptibility, cardiovascular disease, medications, genetic differences in caffeine metabolism, concurrent stimulants, sleep deprivation, rapid consumption, exercise and environmental heat.
4.2 Sleep and Neurobehavioral Effects
Sleep disturbance represents one of the most consistent concerns surrounding adolescent caffeine exposure.
Caffeine can delay sleep onset, reduce total sleep duration and impair sleep quality.
Sleep deprivation → daytime fatigue → caffeine consumption → delayed sleep → further sleep deprivation.
This cycle is particularly relevant among adolescents combining school schedules with gaming, social media, studying and prolonged nighttime screen exposure.
4.3 Anxiety and Neurological Effects
At higher exposure levels or among susceptible individuals, caffeine may produce nervousness, tremor, anxiety, agitation, headache, panic-like symptoms and insomnia.
At very high doses, severe caffeine toxicity may involve seizures and serious cardiovascular complications.
4.4 Renal Effects: Emerging but Predominantly Preclinical Evidence
Recent preclinical research has raised questions regarding the possible renal consequences of repeated energy-drink exposure.
A 2026 systematic review and meta-analysis assessed 19 preclinical studies, predominantly involving rodent models, and reported alterations in renal biomarkers and structural changes in some experiments.
These findings warrant attention but do not establish that ordinary energy-drink consumption causes chronic kidney disease in humans.
The appropriate conclusion is that preclinical studies identify a renal safety signal requiring further human research.
4.5 Sugar and Metabolic Burden
Many conventional energy drinks contain substantial quantities of free sugar, although sugar-free formulations are increasingly common.
High habitual consumption of sugar-sweetened beverages contributes to excessive energy intake, weight gain, obesity risk, dental caries and metabolic disease.
Replacing sugar with non-nutritive sweeteners removes the sugar load but does not eliminate concerns associated with caffeine, sleep disturbance, acidity or stimulant exposure.
“Sugar-free” does not mean physiologically neutral.
V. Adolescents as a Higher-Risk Population
5.1 Lower Body Mass
A fixed container produces a larger pharmacological dose per kilogram in a smaller individual.
This makes package size and total caffeine per container especially important in youth exposure.
5.2 Neurodevelopment
Human neurodevelopment continues throughout adolescence and into young adulthood.
Adolescence is an extended period of continuing maturation involving executive control, reward processing, sleep regulation and behavioral decision-making.
5.3 Alcohol and Energy Drinks
Energy drinks are sometimes consumed together with alcohol.
This represents a distinct risk environment because stimulant effects may modify behavior without reversing alcohol-induced impairment.
The public-health concern therefore includes nightlife, binge drinking and prolonged wakefulness, not merely a biochemical interaction.
VI. Sport, Performance and the Hydration Illusion
6.1 Sport Creates a Powerful Implied Health Message
Sport is naturally associated with fitness, health, endurance, strength, recovery, hydration and physical achievement.
Consequently, commercial association with sport can communicate a functional message even when no explicit health claim is made.
A large branded energy-drink can at a finish line does not have to state “Drink this to hydrate.” The sporting context itself can generate the association.
6.2 Performance Enhancement Is Not Rehydration
Caffeine may improve certain aspects of adult athletic performance.
That does not transform a caffeinated beverage into a hydration product.
A substance can improve alertness or reduce perceived exertion while failing to provide adequate sodium replacement, optimal carbohydrate concentration or an appropriate fluid-replacement strategy.
VII. Lithuania: Strong Sales Protection but a Sports-Marketing Bypass
7.1 Lithuania’s Under-18 Sales Prohibition
Lithuania was one of the first European states to prohibit energy-drink sales to minors.
Lithuanian law defines an energy drink for these purposes principally as a non-alcoholic beverage containing more than 150 mg/l caffeine, including qualifying formulations containing caffeine together with other central-nervous-system-active substances.
Since 1 November 2014, it has been prohibited to sell, purchase for or otherwise transfer qualifying energy drinks to persons under 18.
Source: Lithuanian legislation – e-Seimas.
7.2 Advertising and Sponsorship Restrictions
Lithuanian rules also restrict energy-drink promotion in educational institutions attended by minors and at sporting, concert, charity and other events intended for persons under 18, as well as advertising for such events.
Free promotional distribution to persons under 18 is also prohibited.
Source: Lithuanian State Food and Veterinary Service.
The key regulatory problem is that an event “intended for persons under 18” is not necessarily the same as a mixed-age event in which 16- or 17-year-olds are permitted to participate.
VIII. The Lithuanian Regulatory Bypass
8.1 The Critical Words: “Intended for Minors”
The central legal issue lies in the formulation “events intended for persons under 18.”
This is not automatically equivalent to:
“events in which persons under 18 participate.”
A mainstream marathon, cycling competition, wakeboarding event, esports competition or public sporting festival may be designed for a general population while nevertheless having adolescent participants and spectators.
Under the narrower statutory wording, the presence of minors does not necessarily transform such an event into an event “intended for persons under 18.”
This creates a potential regulatory bypass.
8.2 Legislative History and the Scope of Protection
Earlier Lithuanian legislative proposals contemplated broader language that would also have captured events in which persons under 18 participate.
The final wording instead focuses on events intended for minors.
The policy significance is substantial.
Had the broader formulation been retained, mixed-age competitions involving 16- and 17-year-old competitors could have fallen more clearly inside the protective scope.
Under the narrower formulation, the legal analysis can instead depend on how the event itself is characterized.
8.3 A Concrete 2026 Example
Official rules for Red Bull WakeDuel 2026 in Lithuania stated that Lithuanian qualification was open to participants aged 16 years and older.
Source: Red Bull WakeDuel Rules.
A 16- or 17-year-old may therefore be legally too young to purchase the qualifying energy drink, yet old enough to participate in a sporting competition carrying that energy-drink brand.
This does not by itself establish that the organizer has violated Lithuanian advertising law.
It demonstrates a gap between the protective purpose of the age restriction and the scope of sports-marketing exposure that minors may still encounter.
8.4 Exposure Extends Beyond a Single Competition
The broader Lithuanian energy-drink media environment illustrates the close integration of brand identity with sport, athlete content and competitive events.
Modern exposure occurs not only through direct advertising but through event naming, social media, video, athlete imagery, branded structures and repeated association with sporting achievement.
Example: Red Bull Lithuania.
IX. From Advertising to Environmental Marketing
9.1 Why Traditional Advertising Definitions May Be Insufficient
Classic advertising regulation was largely designed around identifiable promotional messages such as television advertisements, posters, billboards and commercial announcements.
Modern experiential marketing may operate without an explicit product claim.
Commercial communication can instead be embedded in:
- event names;
- registration pages;
- starting arches;
- finish lines;
- barriers;
- tents;
- podiums;
- athlete uniforms;
- branded refrigerators;
- inflatable cans;
- vehicles;
- photography backgrounds;
- social-media videos;
- livestreams;
- influencer and athlete content.
For adolescents, repeated brand exposure within an emotionally positive context of achievement, fitness, excitement and social identity may be more influential than a traditional isolated advertisement.
9.2 Corporate Brand and Product Brand Can Be Identical
Where consumers primarily recognize the corporate trademark as the name of an energy drink, the distinction between “corporate sponsorship” and “product advertising” may become less meaningful from a behavioral perspective.
The logo itself can function as product communication.
X. The Policy Contradiction
Lithuania can therefore communicate two potentially contradictory messages to adolescents.
Public-health message
“You are under 18 and therefore may not legally purchase this qualifying energy drink.”
Marketing environment
“The same trademark may be associated with athletes, competitions, endurance, physical performance and sporting achievement in environments you can attend or sometimes enter as a competitor.”
If the purpose of the age restriction is to reduce stimulant exposure and encourage healthier beverage choices among minors, regulation should consider not only who can purchase the product but also how the product is culturally normalized before adulthood.
XI. Why This Matters for Hydration
The Lithuanian sports-marketing issue directly reinforces the central scientific argument of this article.
Sporting environments naturally imply hydration.
A runner, cyclist or wakeboard athlete sweats. Spectators understand that athletes require fluid replacement.
Young consumers therefore encounter beverage branding in precisely the environment where hydration is most salient.
Even without an explicit hydration claim, persistent energy-drink branding around sport can weaken the distinction between:
- stimulation; and
- rehydration.
A public-health framework should address not only false textual claims but also contextual claims produced by marketing environments.
XII. A More Coherent Lithuanian Regulatory Model
Lithuania could close the present gap without prohibiting all adult energy-drink consumption or all commercial sponsorship.
A proportionate amendment could extend protection to events:
- intended for persons under 18;
- in which persons under 18 are eligible to participate; or
- where minors can reasonably be expected to constitute a substantial proportion of participants or spectators.
Additional measures could include:
- restrictions on prominent energy-drink product imagery at mixed-age amateur sporting events;
- stronger controls on product sampling;
- clearer separation between corporate sponsorship and direct product promotion where feasible;
- age-sensitive digital marketing controls;
- restrictions on large product replicas and branded beverage installations in youth-accessible zones;
- explicit prohibition of marketing that implies energy drinks are appropriate for hydration, thirst-quenching or routine fluid replacement during sport.
If a population is legally considered too young to purchase a high-caffeine energy drink, policymakers should also examine whether that same population should be systematically exposed to marketing that associates the product with sport, endurance and physical achievement.
XIII. Broader European Regulatory Implications
Lithuania is not alone in attempting to protect minors from energy-drink exposure.
Several European countries now impose age-related restrictions, while EU law already requires warnings on certain high-caffeine beverages.
Lithuania illustrates a second-generation regulatory problem:
What happens after a country restricts sales to minors but leaves indirect brand exposure through sport and culture largely untouched?
Future European policy may therefore need to consider:
- product availability;
- caffeine concentration;
- total caffeine per container;
- labeling;
- direct advertising;
- sponsorship;
- brand exposure;
- youth participation in mixed-age events;
- digital marketing;
- implied association with sport and hydration.
XIV. Scientific and Regulatory Limitations
Energy drinks are not chemically uniform products. Caffeine, sugar, serving size and additional ingredients vary substantially.
Many studies involving adolescents are observational and therefore demonstrate association rather than definitive causation.
Serious acute adverse events remain uncommon relative to the very large number of energy drinks consumed.
Renal evidence remains substantially more preliminary than evidence concerning caffeine, sleep and cardiovascular effects.
Likewise, the presence of energy-drink branding at a sporting event does not prove that every exposed adolescent will subsequently consume the product, and not every mixed-age sporting sponsorship should automatically be characterized as unlawful.
The Lithuanian argument is more specific:
The statutory structure may permit a marketing exposure that appears inconsistent with the public-health objective underlying the under-18 sales restriction.
This is appropriately described as a regulatory gap or practical regulatory bypass, rather than automatically as an illegal act.
XV. Conclusions
Energy drinks should be clearly distinguished from hydration beverages.
Because they contain water, it is scientifically inaccurate to assert that ordinary consumption universally causes dehydration.
However, this does not make energy drinks appropriate rehydration products.
Their principal functional effect is generally stimulation, predominantly through caffeine-mediated antagonism of adenosine receptors.
Water remains the appropriate default beverage for ordinary hydration.
During prolonged strenuous exercise with substantial sweat loss, appropriately formulated electrolyte and carbohydrate beverages may have a specific role.
For children and adolescents, caution is particularly justified. Lower average body mass increases caffeine exposure per kilogram, sleep disruption has important developmental and educational consequences, and leading pediatric organizations recommend avoidance of caffeinated stimulant beverages.
The Lithuanian experience reveals an additional dimension of the problem.
Lithuania prohibits sales of qualifying energy drinks to persons under 18 and restricts advertising and sponsorship at events intended for minors.
Yet the law does not automatically extend the same protection to every mixed-age event in which minors may participate.
The result is a fundamental regulatory inconsistency:
A 16- or 17-year-old can be legally prohibited from buying an energy drink while still participating in or attending a sporting environment prominently associated with that energy-drink trademark.
The next generation of energy-drink regulation should therefore examine the entire exposure pathway:
product formulation → package size → advertising → sporting sponsorship → digital promotion → adolescent participation → consumer perception.
Stimulation should not be presented as hydration, and a population legally protected from purchasing stimulant beverages should not lose that protection merely because the advertising reaches them through sport rather than through the point of sale.
Selected Sources
- European Food Safety Authority (EFSA) — Caffeine
- 2025 recommendations on beverages for children and adolescents
- Republic of Lithuania — Energy drink legislation
- Lithuanian State Food and Veterinary Service — Advertising restrictions
- Red Bull WakeDuel — Published competition rules
- Red Bull Lithuania — Sports and event content
- World Health Organization — Healthy Diet
- U.S. FDA — How Much Caffeine Is Too Much?
This article is intended for scientific, educational and public-policy discussion. It does not constitute individual medical advice or a legal opinion regarding any specific event, organizer, advertiser or company.