Energy drinks (EDs) are non-alcoholic beverages with high caffeine and sugar, often combined with stimulants such as taurine, ginseng, and guarana (1, 2). The category has expanded rapidly worldwide, with ~200 brands in more than 140 countries (3). Caffeine content varies widely (≈50–505 mg/serving), compared with ~90 mg in 250 mL of coffee, ~50 mg in 250 mL of tea, and ~34 mg in 500 mL of cola (4, 5). EFSA proposes daily “generally safe” intakes of ~3 mg/kg for children/adolescents and ~5.7 mg/kg for healthy adults, levels that ED consumption can meet or surpass, sometimes doubling or tripling these thresholds (4).

Across studies, ED use is more prevalent in males than females at most ages (6–12). Age gradients are less consistent. Some studies have found that consumption levels increase with age (9, 13–19), while others report the opposite (20–22).

ED consumption typically begins early, especially during adolescence, driven by intensive advertising, perceived “functional” benefits, and the social normalization of the product (12, 23). Promotional campaigns emphasize that EDs improve performance and alertness, increase stamina and energy, reduce fatigue, and optimize overall functioning, while also appealing to sensation-seeking and masculine traits (24–26). Consistent with this positioning, the most frequently reported motives among adolescents and university students include studying and enhancing academic performance, engaging in sports and improving physical performance, “boosting energy/alertness,” staying awake, and, to a lesser extent, taste (9, 10, 12, 24, 25, 27, 28).

Gender-targeted marketing, specifically aimed at young males, has been identified as a key determinant of the higher ED consumption observed among adolescents and young adults (12, 24, 25, 29, 30). Consistent with this, the highest prevalences are found in these groups, with adolescents as the main consumers, followed by young adults (6, 7).

Scientific evidence links ED consumption with poorer health and well-being indicators. Population and student studies show that high or frequent consumption is associated with more health complaints and worse self-rated health (9, 15, 16, 31–33). In particular, Khouja et al. (9) observed that those who consume EDs ≥ 5 days/week have a higher risk of poor psychological and physical well-being and are four times more likely to report low academic and overall well-being. Related findings link ED use with poorer perceived health (15, 16, 33, 34). Frequent consumption is associated with mental health problems (anxiety, depressive symptoms, stress, suicidal ideation and behaviors) and with increases in ADHD symptoms and behavioral problems (35–37). In the physical domain, reported effects include sleep disturbances (shorter duration, poorer quality) and greater psychological distress (9, 11), as well as physiological effects, especially among adolescents, such as palpitations, elevated blood pressure, increased arterial stiffness, and signs of insulin resistance (38–40).

In Spain, ED consumption is common among both young adults and adults. According to the Spanish Survey on Alcohol and Other Drugs, EDADES (49), 14.2% of the population aged 15–64 consumed EDs in the past 30 days. The highest prevalence is observed in 15–24-year-olds (37.6%; 42.8% in men and 32.1% in women), a band that overlaps the lower end of our adult sample (18–24), indicating elevated use among younger adults. Moreover, mixing EDs with alcohol in leisure settings is common, a practice that increases associated risks (49).

Socioculturally, consumption is linked to the pursuit of academic and athletic performance, prolonged wakefulness, and nightlife, patterns widely described among university students and young adult healthcare trainees in Spain (41, 42, 49).

The regulatory framework requires specific high-caffeine warnings on labels (Regulation [EU] No 1169/2011) but does not set a nationwide minimum purchase age. Some autonomous communities have proposed or adopted restrictions (e.g., initiatives in Galicia and limitation measures in Asturias), reflecting social concern (49). Internationally, several countries apply stricter measures: a sales ban to minors in Sweden, pharmacy-only dispensing in Norway, and legal limits on caffeine/taurine content in Germany and Denmark (3). In the United Kingdom, major retail chains have voluntarily restricted sales to those under 16 (69).

Furthermore, the systematic review by Ajibo et al. (6) consistently reports an association between ED consumption and the use of substances such as alcohol, tobacco, and cannabis, highlighting that individuals who consume EDs are more likely to use these other substances, especially when ED consumption is frequent.

The evidence suggests that regular ED consumption is associated with poorer quality of life through three main pathways: sleep disturbances, deteriorations in mental health, and behavioral changes. A cross-sectional study in Norway involving more than 53,000 university students showed a dose–response relationship between consumption frequency and shorter/less efficient sleep, as well as higher insomnia rates (43). Given that adequate sleep is a key determinant of quality of life, this association is clinically relevant (43).

At the longitudinal level, a follow-up study of young Australian adults found that increases in ED consumption predicted greater symptoms of depression, anxiety, and stress, especially among men, suggesting a sustained impact on psychological well-being (44). Reviews corroborate these trends. Although there may be immediate effects on alertness, frequent intake is linked to higher stress, anxiety, and depressive symptoms (17, 18) and to an overall decline in well-being and quality of life (45). In Europe, behavioral effects (mixing with alcohol, impulsivity) and physiological effects (tachycardia, hypertension) have also been described, with potential social and functional repercussions (46).

Given the evidence presented, it is necessary to further explore the relationship between ED consumption and quality of life, considering the increasing use of these products and their potential implications for physical, mental, and social health. While numerous studies have documented negative associations in adolescent populations, research focused on young adults and the general adult population remains scarce.

Given that the evidence has focused mainly on adolescents, it is necessary to study the relationship between energy drink consumption and quality of life in the Spanish adult population. In this context, this study examines the association between ED consumption and quality of life in Spanish adults, with a primary focus on sex differences; age is considered an essential descriptive and adjustment variable rather than a primary exposure. The research questions guiding this study are: Is there a significant relationship between ED consumption and perceived quality of life? Does this relationship vary according to sex? Addressing these questions will contribute to a deeper understanding of the phenomenon and generate evidence to inform health promotion and prevention strategies tailored to the characteristics of different population groups.

Data were collected from 1,146 individuals (73.7% women, n = 845) aged between 18 and 54 years, with a mean age of 27.0 years (SD = 8.61). A total of 82.5% (n = 945) of the sample was under 34 years old (see Table 1).

Most participants reported having completed university (47.9%, n = 549) or secondary education (51.1%, n = 586). Considering the age distribution, the most common living arrangement was living with the family of origin (43.4%, n = 497) or sharing an apartment (19.8%, n = 227), followed by those living with their own nuclear family (15.8%). Regarding occupation, 57.5% (n = 659) report that they are working and 41.1% (n = 471) that they are studying.

Perceived health was mostly positive, with 81.9% (n = 926) rating it as “good” or “very good.” General quality of life received a mean score of 3.7, and satisfaction with health was rated at 3.5 (on a 5-point scale). Domain scores on the WHOQOL-BREF were also relatively high (on a 0–100 scale): physical health 68.2; psychological health 59.0; social relationships 64.6; and environment 62.3.

Regarding substance use, 62.7% (n = 718) of the sample reported having consumed ED at some point in their lives, 38.5% (n = 441) in the past year, 21.3% (n = 244) in the past month, and 5.7% (n = 65) reported daily consumption. In addition, 76.8% had consumed alcoholic beverages in the previous month, 37.6% (n = 431) reported tobacco use, and 16.0% (n = 183) cannabis use.

Table 2 presents the prevalence of ED consumption. A total of 21.3% (n = 244) reported occasional consumption, while 5.7% (n = 65) reported daily use. Prevalence was significantly higher among men (10.6% vs. 3.9% daily; and 30.6% vs. 18.0% occasional use). Additionally, 37.3% (n = 428) indicated they had never tried EDs (41.9% of women and 24.6% of men). Higher consumption rates were also observed among younger age groups. Among participants under 25 years of age, 6.5% (n = 42) reported daily consumption, compared to 5.4% (n = 16) in the 25–34 age group. This percentage decreased to 4.0% (n = 5) among those aged 35–44, and to 2.6% (n = 2) among individuals over 45 years of age.

Among the total number of ED consumers (n = 718), 89.8% reported that on a typical day of consumption, they drink one serving (88.2% of women and 92.6% of men; see Table 3); 6.6% (n = 29) reported consuming two servings (6.8% of women and 6.2% of men); and 3.6% (n = 16) reported consuming three or more servings (5.0% of women and 1.2% of men).

The linear regression models estimating the relationship between ED consumption and quality of life, adjusted for potential confounders, indicate that the adjusted scores of ED consumers are similar in most cases to those of non-consumers (used as the reference group; Table 4), except for men in the mental health domain, whose score is significantly lower (−8.72 [95% CI − 16.999 to −0.45], p = 0.039). Although most associations did not reach statistical significance, the point estimates suggested lower scores in the physical and mental health domains, as well as in environment, compared with those who reported never consuming EDs, both among men and women and among occasional and daily ED consumers.

To further explore the perceived quality of life among the study population, selected items from the WHOQOL-BREF scale were analyzed (see Table 5). It can be seen that the cumulative odds (for daily consumers versus non-consumers) of responding affirmatively to the presence of negative feelings (3.53 [95% CI 1.28 to 9.75], p = 0.015) are significantly higher in men, but not in women. Men also show significantly higher odds of being dissatisfied with themselves (2.71 [95% CI 1.07 to 6.89], p = 0.036). Women, however, only exhibit significantly higher odds in perceiving a less healthy environment (2.58 [95% CI 1.28 to 5.17], p = 0.008).

The findings of this study confirm that ED consumption is particularly concentrated among males and younger age groups, which is consistent with previous studies identifying a higher prevalence among adolescents and young adults, along with a gender-based distribution (8–12). However, due to the cross-sectional nature of the study, the observed relationships between ED consumption and quality of life domains should be interpreted as associations, not causal effects.

Marketing also helps explain these differences. In Spain, as in other countries, advertising for EDs is primarily targeted at young adult men and links consumption with energy, masculinity, athletic performance, and fun (24, 25, 29, 30). This strategy fosters the normalization of use and reinforces the perception of “functional” benefits in academic, social, and sports contexts. From a public health perspective, these messages are a priority target for regulation due to their potential to entrench risk-prone attitudes and legitimize frequent ED consumption.

Although most individuals in this sample reported consuming a single unit per occasion, approximately 10% reported multiple units (6.6% two and 3.6% three or more), which could lead to caffeine intakes exceeding levels considered safe, especially among low–body-weight youth (4). Frequent ED consumption is consistently associated with sleep disturbances (shorter duration, poorer quality, insomnia, difficulty falling asleep, and other disorders; 16) (6–12, 26, 32). The likely mechanism includes the effects of caffeine and other stimulants, which disrupt circadian rhythms and impair sleep quality (51). Taken together, these alterations have negative repercussions for mental health and overall well-being (6, 7). The results of the present study are consistent with this evidence, as daily ED consumers reported dissatisfaction with sleep more frequently, especially men. These findings reinforce the need to consider the impact of ED consumption on sleep as a key mechanism in its relationship with perceived quality of life.

This exposure may also contribute to other adverse effects described in the literature. Several studies have documented associations between frequent ED consumption and physical discomfort, as well as psychological and physiological problems (9, 11, 34, 36–40), suggesting that beyond occasional use, habitual consumption may negatively affect perceived quality of life. Although our findings do not allow causal inferences, they align with prior evidence indicating a potentially harmful impact of ED consumption on well-being (9, 15, 16, 31–33).

In this study as well, daily ED consumers, compared to non-consumers, significantly higher odds of reporting negative feelings and dissatisfaction with themselves, particularly among males. Among females, a higher likelihood of perceiving their environment as less healthy was observed.

The analysis of specific WHOQOL-BREF items also showed that men who consume EDs daily are more likely to report negative moods and lower self-satisfaction compared to those who do not consume them. This trend is consistent with the literature, which has documented adverse effects of ED consumption on psychological health (6, 11, 27, 44).

Gender differences in perceived health and in ED consumption stem from a combination of social, cultural, physiological, and hormonal factors. Among women, taking on greater caregiving responsibilities and prolonged exposure to chronic stress have been associated with poorer perceived health and lower subjective well-being (52–54). This context may encourage the use of EDs as a strategy to cope with fatigue and stress; however, their physiological effects (e.g., sleep disturbances, nervousness) can paradoxically worsen the perception of an unhealthy environment and reduce quality of life (55). Moreover, sociocultural factors may heighten women’s awareness and critical appraisal of issues such as safety, social support, and domestic workload, leading to lower self-reported scores in health and environment domains when multiple stressors converge (56, 57).

In contrast, men more frequently show negative associations between ED consumption and mental health, likely mediated by masculine norms that promote vigor, risk-taking, and identification with models of physical or athletic toughness, behaviors often accompanied by higher caffeine and ED intake. This pattern has been linked in longitudinal studies to a progressive worsening of anxiety and depression symptoms (44, 58, 59).

These social dynamics are compounded by biological differences. Sex-based variations have been documented in responses to caffeine (pharmacokinetics, cardiovascular effects) and in subjective and physiological responses (60, 61), which could modulate the risk of adverse effects on mood and sleep; the evidence, however, is complex and not uniform. From a hormonal perspective, in women, fluctuations related to the menstrual cycle, pregnancy, or menopause may increase sensitivity to stress and fatigue, reinforcing both negative perceptions of the environment and the use of caffeine as a compensatory resource (60). In men, testosterone has been associated with greater sensation-seeking and risk-taking, which could help explain higher and more problematic ED use and, consequently, a less favorable mental health impact (17, 18). In any case, these biological differences interact closely with social and gender factors and should not be interpreted in isolation.

Finally, adult-focused motivational evidence complements these mechanisms. Studies in adults and young adults indicate motives centered on stress-coping and performance (e.g., studying, managing workload/fatigue), as well as social reasons (nightlife and alcohol-mixed use) (10, 27, 28, 55, 62). Social-context motives, including AmED (alcohol mixed with energy drinks), are documented and linked to risk behaviors (30, 63, 64). Taken together, these findings suggest a gendered motivational pattern: men may be more strongly driven by performance/energy and peer/social contexts (including AmED), whereas women may more often report stress- and fatigue-coping motives. This pattern aligns with the sex-specific associations observed in our study and provides a plausible behavioral pathway that complements our adjusted models.

The broader gender-and-health literature based on the WHOQOL-BREF shows consistent differences in perceived quality of life. In a study of 1,147 adults, Islam (65) found poorer outcomes among women in nearly all domains (physical, psychological, and environmental), except the social domain. Similar findings have been reported in other contexts: women showed poorer physical health and lower overall health satisfaction (66); female medical students scored lower than males in the physical and psychological domains (67); and female caregivers of people with rare diseases had lower scores in social relationships (68). Taken together, this evidence situates ED consumption within a broader framework of gender health inequalities and underscores the need to integrate biological and psychosocial determinants when analyzing its differential impact.

Finally, although the adjusted models did not show statistically significant differences across all quality of life domains, there is an average reduction of approximately 4–9 points in mental health and environment scores among daily consumers compared with non-consumers, in both men and women. These findings underscore the need for further longitudinal research on the effects of continued ED consumption in young adult and adult populations, and highlight the relevance of public health interventions aimed at regulating the marketing of these products and raising awareness of their potential risks.

This study provides empirical evidence on ED consumption and its relationship with perceived quality of life in young adult and adult populations. The findings reveal that 62.7% of the sample have consumed EDs at least once, 21.3% did so in the past month, and 5.7% consume them daily, especially among males and younger age groups, with a predominant pattern of occasional use, although not without cases of daily consumption and multiple servings per occasion.

Among young adult individuals (18–30 years), frequent ED consumption is significantly associated with poorer perceptions of mental health and environmental quality, particularly among those who report daily intake. This association is more pronounced in males, who exhibit higher consumption rates and a greater likelihood of experiencing emotional distress, personal dissatisfaction, and sleep-related difficulties. Among young adult females, frequent ED consumption is more clearly linked to negative evaluations of their environment, which may reflect a greater impact of social, academic, or relational factors.

In the adult population, although prevalence is lower, daily ED consumption is still associated with lower scores in mental health and environmental perception, suggesting that the adverse effects of these beverages are not limited to adolescence or early adulthood. The persistence of this pattern in older age groups underscores the need to consider ED consumption as a relevant public health issue beyond the school or youth context.

Overall, these results indicate that habitual ED use may negatively impact perceived well-being, particularly in terms of psychological health and social environment, and highlight the importance of implementing preventive strategies that address both access to these products and misconceptions about their effects. The observed differences by sex and age group emphasize the need for differentiated and context-sensitive interventions that take into account both individual and social factors influencing ED consumption.

Based on these findings, a coordinated strategy that takes into account age and sex is recommended: (1) education and health-promotion for young adults and families (school/university modules on stimulant use, sleep hygiene, and risks of alcohol-mixed energy drinks); (2) risk-proportionate marketing/sales regulation (youth-audience and placement restrictions, prominent front-of-pack high-caffeine warnings, standardized caffeine caps per serving); (3) consider age-of-sale limits and point-of-sale warnings; (4) clinical and public-health actions (routine screening in primary care and student health, brief advice for frequent users, targeted counseling for sleep/mental-health problems); and (5) monitoring and enforcement focused on AmED communications and sales. Together, these measures would support informed choices, curb risky patterns, and align Spain with emerging European best practices.