Energy Drink Consumption Among Adolescents in Northern Spain: Habits, Risk Perception and Associated Factors

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article describes energy drink prevalence and predictors of energy drink intake, in a Spanish adolescent (13-18 yr) sample population. The article was interesting and easy to read but the methods section is significantly lacking content about the survey. The reader has to make many assumptions. As this manuscript focuses solely on results of a survey, more detail is needed. I’ve provided suggestions and questions to help delineate areas for improvement (see below). Additionally, there is no context about cultural norms in Spain related to alcohol and tobacco use in the 13-18 yr age group. Are there age restrictions for legal use? For example, in the United States, anyone under the age of 21 is prohibited from buying or using alcohol or tobacco, thus it seems a bit alarming (and more problematic) that adolescents are reporting alcohol and tobacco use (whether alone or with energy drinks). But I appreciate the opportunity to review your manuscript and look forward to your revisions.

 

nutrients-4225879-peer-review-v1

Title: Energy drink consumption among adolescents in Northern Spain: habits, risk perception and associated factors

 

Overall: The article describes energy drink prevalence and predictors of energy drink intake, in a Spanish adolescent (13-18 yr) sample population. The article was interesting and easy to read but the methods section is significantly lacking content about the survey. The reader has to make many assumptions. As this manuscript focuses solely on results of a survey, more detail is needed. I’ve provided suggestions and questions to help delineate areas for improvement. Additionally, there is no context about cultural norms in Spain related to alcohol and tobacco use in the 13-18 yr age group. Are there age restrictions for legal use? For example, in the United States, anyone under the age of 21 is prohibited from buying or using alcohol or tobacco, thus it seems a bit alarming (and more problematic) that adolescents are reporting alcohol and tobacco use (whether alone or with energy drinks). But I appreciate the opportunity to review your manuscript and look forward to your revisions.

 

Introduction:

Line 67: Should “Eds” be “EDs”?

 

Methods:

Lines 123-127: This study is solely based upon variables collected and analyzed from an ad-hoc questionnaire modeled after a survey from a cited survey. The reader should not have to find that article to understand more about the survey. Consider adding a table to present more detail about your variables, such as the their corresponding question from the survey, and the response options. Was the survey pre-tested beforehand for face or content validity? What sociodemographic and personal data were collected? For consumption variables (ED, alcohol, tobacco), were the categories in the table the same as from the survey or were data collected in another format and recategorized / manipulated for analysis? For risks / reasons / locations, were categorical response options provided, or were these questions open-ended and a researcher categorized the responses? Was there a procedure to adjudicate response categorization by the researcher staff? You’ll note other questions that arose when reviewing the tables. If the methods have sufficient detail, it will be easier for the reader to understand and interpret your findings.

Line 133: What groups? This has not been introduced yet. This could be addressed in the Participants section, along with what EOS and BACH are defined as, by age group.

Line 134: Please address the variables that you controlled for.

 

Results:

Lines 142-145: Recommend reporting standard deviation at no more than the hundredth decimal place.

Lines 156-157: Providing p-values in parenthesis adds little value since a p-value just verification that you attain a level of significance noted in your methods alpha. Regardless if 0.05, 0.001, 0.0001, the data is either significantly different between groups or it is not. And you stated this information was statistically significant. Instead you could add the proportion in parenthesis with or without the p-values to ease the burden of viewing the tables for major findings. For example, "... bars (12.7% ESO vs. 27.8% BACH), nightclubs (…),… (Table 2).”

It seems intuitive that adolescents in ESO (younger ages) would have lower intake in bars and nightclubs? Are there no age restrictions for entry to these establishments? Beyond energy drink intake, it seems more alarming that adolescents between 13-16 are frequenting bars and nightclubs. Addressing cultural norms in the methods section when defining this variable would be helpful to the reader.

Line 165: Consider a summary statement, such as, "The majority of participants reported increased heart rate (91.9%), hyperactivity (83.2%), and high blood pressure (62.2%) as perceived risks of ED consumption (Table 4). Unexpectedly, 8.6% reported no perceived risk of ED consumption.”

Lines 171-173: Instead of just reporting the p-value, consider stating the likelihood or odds in the narrative. For example, "ED consumption was 3.1 times and 1.9 times more likely if consumed with alcohol and tobacco use, respectfully. Males were twice as likely as females to consume ED.”

 

Table 1: Tables should stand along from the narrative. 

• Acronyms should be spelled out in footnote. You could consider just using age range for ESO and BACH column headings. It would be easily for the reader since age and education are strongly and positively associated.
• Since conducted in Spain, please provide something in the methods narrative to describe ESO and BACH.
• Since reporting 7 hr or less of sleep, the reader assumes that the remaining participants slept 8 hr or more. Was sleep hours captured as a continuous variable and then categorized by the researcher or were the participants asked on the survey for a dichotomous response (7 or less vs. 8 or more). This should be addressed in the methods.
• For tobacco use – how is occasionally defined? Does daily also include the weekends?
• For alcohol consumption - 2-3 times/wk is a response that could overlap with the weekend as there are only 2 days on the weekend. Should it be 2-3 weekdays/wk? Wondering how this question was asked to the participants and how manipulated by the researcher.
• For energy drinks - what qualifies as habitually vs. occasionally? This should be defined in the methods.

 

Table 2: Acronyms should be spelled out in a footnote. Similar to Table 1, recommend adding the N in the column heading. Curious if participants can list more than one reason and how you treated that information. This should be explained in the methods section (open-ended question or list of options). If a participant can provide more than one reason, I would have expected (n) values to be much higher. Terms like 'concentration augmenting' and 'enhance performance' are more advanced for adolescents 13-18 yrs. Were these used in the survey as displayed in the table, or was the question asked in another way and the researcher categorized responses? As I reader, I would not assume ‘enhanced performance’ related to academic performance as noted in your discussion. These concepts should be clearly described to aid the reader.

 

Table 3: Be consistent in how presented - BACH or Bachille (like Tables 1 & 2). Please add acronyms to the footnotes.  Recommend replacing “patterns" in the title with “proportion of adolescents”.

 

Table 4: Recommend organizing adverse effects in descending prevalence values and also adding a row in the table for 'no perceived adverse effects' with 8.6 (108) to ensure the table captures all participant perceptions. It looks like the participant could provide more than 1 risk. On the survey, where responses offered with a write-in option, or was the question open-ended and the researchers coded later? This should be described in the methods.

 

Discussion:

Lines 210: Performance enhancing does not always mean cognitive or academic. This should be explained better in the methods to aid reader interpretation.

Line 221: I think it is worthwhile to mention the legal age to drink and enter establishments such as bars and nightclubs. This will be a bit alarming for US readers as the legal age is 21 yrs. If culturally this is acceptable in Spain, this should be explained. Otherwise, it seems that alcohol and tobacco use are just as big of a public health concern as ED, especially with combined use.

Line 261: Did you collect any data that would lead you to discuss body image? Perhaps as part of the 'trendy' response? This seems outside of the scope of this paper. Additionally, you present the finding from Wierszejska et al. that more than half of adolescents do not perceive adverse risks, warranting further action, but you only found 8.6% perceived no adverse risk.

Line 271: Beneficial to state the odds or likelihood (i.e., 3.1 times more likely), similar to how you reported Doggett et al in line 273.

Line 274 & 277: Recommend including the likelihood / odds value from your results for gender (2 times for males) and tobacco use (1.9 times).

Lines 289-293: Once your methods are improved, you may have additional limitations related to survey design. For example, having to choose from a select list of risk and location options, how open-ended question responses were categorized and adjudicated by researchers, using a non-validated or pre-tested survey. Additionally, you mentioned that the schools could decide to use a paper vs. online survey format; inconsistent survey format could contribute to systematic bias.

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

Overall, I found the study to be of high quality, methodologically robust, addressing a very relevant public health issue. The large sample size and the focus on risk perception among adolescents provide valuable insights into this field.

 

I believe the manuscript is excellent, though I have identified a few minor points that should be addressed before publication:

Table 1: Please check the "Tobacco consumption" row for the ESO group; there is a small formatting error with the percentage sign.

Terminology: Ensure the abbreviation "EDs" is used consistently throughout the text after its first mention.

Limitations: I recommend adding a few points to this section:

Caffeine Measurement: The study does not measure the exact amount of caffeine consumed, which varies significantly between different brands and serving sizes.

Other Stimulants: It would be beneficial to mention that the consumption of other caffeinated products (such as coffee, tea, or supplements) was not recorded, as these could also influence the results and risk perception.

Once these small corrections are made, I believe the paper will be a strong contribution to the field. I wish you best of luck!

Author Response

 We would like to thank the reviewers for their thorough evaluation of our manuscript and for the constructive comments provided. We greatly appreciate the time and expertise invested in reviewing our work. Below, we address each comment point‑by‑point and describe the corresponding changes implemented in the revised version of the manuscript.

 

Reviewer 2

 

Table 1: Please check the "Tobacco consumption" row for the ESO group; there is a small formatting error with the percentage sign.

Thank you very much. We have removed the percentage symbol.

Terminology: Ensure the abbreviation "EDs" is used consistently throughout the text after its first mention.

Thank you very much for the recommendation. We have revised the text accordingly.

Limitations: I recommend adding a few points to this section:

Caffeine Measurement: The study does not measure the exact amount of caffeine consumed, which varies significantly between different brands and serving sizes.

Other Stimulants: It would be beneficial to mention that the consumption of other caffeinated products (such as coffee, tea, or supplements) was not recorded, as these could also influence the results and risk perception.

Thank you for your thoughtful comment. We have now incorporated this consideration into the Limitations section. Specifically, we added a statement acknowledging that the study did not measure the exact amount of caffeine consumed, nor other sources of caffeine intake, and that future research should include these measurements as well as variables related to body image perception. The paragraph has been revised accordingly

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for addressing all of my concerns. The manuscript is much improved; your methodology has been clarified for the reader. I noticed 2 additional small edits that should be made.

Line 172-173: Recommend adding a unit of measure (% symbol) with values noted in parenthesis.

Table 4: Thanks for reordering the numbers, but the last 2 should be switched to complete action.

Author Response

We thank the reviewers again for their evaluation of our manuscript. Below, we address each comment and outline the corresponding changes made in the revised version of the manuscript.

 

Reviewer 1

Line 172-173: Recommend adding a unit of measure (% symbol) with values noted in parenthesis.

Thank you for your suggestion. We have revised this section and clarified the presentation of the values.

Table 4: Thanks for reordering the numbers, but the last 2 should be switched to complete action

Thank you very much for this observation. We have corrected the order of the last two items in Table 4 accordingly.