Influence of study shift on the interrelationships among chronobiological factors, health practices, and anthropometry in adolescents

Raphael Corrêa Martins; Flávia dos Santos Barbosa Brito; Cintia Chaves Curioni

doi:10.1371/journal.pone.0322617

Peer Review History

Original SubmissionJanuary 2, 2025
2 Jan 2025 Author Response https://doi.org/10.1371/journal.pone.0322617.r001
5 Mar 2025 Decision Letter - Miray Budak, Editor -->PONE-D-25-00055-->-->Influence of study shift on the interrelationships among chronobiological factors, health practices, and anthropometry in adolescents-->-->PLOS ONE Dear Dr. Curioni, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Both reviewers have provided positive feedback and have suggested minor revisions. To ensure clarity and consistency, we kindly request that you address these minor revisions, which will further strengthen your manuscript. Please submit your revised manuscript along with a detailed response to the reviewers’ comments.-->--> -->-->Best regards, Dr. Miray Budak Academic Editor, PLOS ONE ============================== Reviewer 1 The manuscript is technically sound and the use of structural equation modeling (SEM) to analyze interrelationships is an advanced and appropriate choice for dealing with multiple variables and testing theoretical frameworks. Regarding English: in Table 2 there is text that is written in portuguese language. Please develop the limitation section including the reliance on self-reported data (e.g., food practices, screen time, and sleep duration) that may introduce bias or inaccuracies.-->--> Reviewer 2 I have reviewed your manuscript titled “Influence of study shift on the interrelationships among chronobiological factors, health practices, and anthropometry in adolescents.” The study investigates how school shift—morning versus afternoon—affects the complex interrelationships among sleep-related variables, chronotype, screen time, physical activity, dietary practices, and anthropometric measures in adolescents. Using a cross-sectional design with a sample of 925 students aged 14 to 19, you collected data through an online questionnaire and anthropometric measurements. Structural equation modeling was applied to test six path models that explore direct, indirect, and total effects among the variables, with particular attention given to differences between the morning and afternoon shifts. Your findings highlight that factors such as sleep duration, chronotype, and screen time have distinct associations with food practices and body mass index by age, depending on the study shift. These results suggest that the timing of school attendance is an important environmental marker that should be considered in health interventions targeting adolescents. While your work is comprehensive and methodologically detailed, there are several aspects that could be strengthened. First, the cross-sectional design limits the ability to infer causality, which you acknowledge; however, further discussion on this limitation and its implications for interpreting the results would improve the manuscript. Second, the reliance on self-reported measures for variables such as sleep duration, food practices, and screen time introduces potential bias. It might be useful to discuss how these biases could affect your findings or consider supplementing the questionnaire data with objective measures in future studies. Third, although the formation of latent variables for food practices is innovative, the rationale behind the grouping of certain items—particularly the separate treatment of vegetables and fruits—could be explained more thoroughly to clarify why these items did not load with other healthy eating indicators. Additionally, while the structural equation models appear robust, a more detailed presentation of the model fit indices and any modifications made based on the “modification indices” would enhance transparency. In summary, your study provides valuable insights into the influence of school shift on adolescent health behaviors and nutritional status. Addressing these methodological and interpretative issues would further solidify the conclusions and offer a clearer pathway for future interventions. ============================== Please submit your revised manuscript by Apr 19 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript:--> A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. 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Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols . We look forward to receiving your revised manuscript. Kind regards, Miray Budak Academic Editor PLOS ONE Journal Requirements: When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 2. When completing the data availability statement of the submission form, you indicated that you will make your data available on acceptance. We strongly recommend all authors decide on a data sharing plan before acceptance, as the process can be lengthy and hold up publication timelines. Please note that, though access restrictions are acceptable now, your entire data will need to be made freely accessible if your manuscript is accepted for publication. This policy applies to all data except where public deposition would breach compliance with the protocol approved by your research ethics board. If you are unable to adhere to our open data policy, please kindly revise your statement to explain your reasoning and we will seek the editor's input on an exemption. Please be assured that, once you have provided your new statement, the assessment of your exemption will not hold up the peer review process. 3. We notice that your supplementary tables are included in the manuscript file. Please remove them and upload them with the file type 'Supporting Information'. Please ensure that each Supporting Information file has a legend listed in the manuscript after the references list. 4. Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. Reviewers' comments: -->Reviewer 1 The manuscript is technically sound and the use of structural equation modeling (SEM) to analyze interrelationships is an advanced and appropriate choice for dealing with multiple variables and testing theoretical frameworks. Regarding English: in Table 2 there is text that is written in portuguese language. Please develop the limitation section including the reliance on self-reported data (e.g., food practices, screen time, and sleep duration) that may introduce bias or inaccuracies.-->--> Reviewer 2 I have reviewed your manuscript titled “Influence of study shift on the interrelationships among chronobiological factors, health practices, and anthropometry in adolescents.” The study investigates how school shift—morning versus afternoon—affects the complex interrelationships among sleep-related variables, chronotype, screen time, physical activity, dietary practices, and anthropometric measures in adolescents. Using a cross-sectional design with a sample of 925 students aged 14 to 19, you collected data through an online questionnaire and anthropometric measurements. Structural equation modeling was applied to test six path models that explore direct, indirect, and total effects among the variables, with particular attention given to differences between the morning and afternoon shifts. Your findings highlight that factors such as sleep duration, chronotype, and screen time have distinct associations with food practices and body mass index by age, depending on the study shift. These results suggest that the timing of school attendance is an important environmental marker that should be considered in health interventions targeting adolescents. While your work is comprehensive and methodologically detailed, there are several aspects that could be strengthened. First, the cross-sectional design limits the ability to infer causality, which you acknowledge; however, further discussion on this limitation and its implications for interpreting the results would improve the manuscript. Second, the reliance on self-reported measures for variables such as sleep duration, food practices, and screen time introduces potential bias. It might be useful to discuss how these biases could affect your findings or consider supplementing the questionnaire data with objective measures in future studies. Third, although the formation of latent variables for food practices is innovative, the rationale behind the grouping of certain items—particularly the separate treatment of vegetables and fruits—could be explained more thoroughly to clarify why these items did not load with other healthy eating indicators. Additionally, while the structural equation models appear robust, a more detailed presentation of the model fit indices and any modifications made based on the “modification indices” would enhance transparency. In summary, your study provides valuable insights into the influence of school shift on adolescent health behaviors and nutritional status. Addressing these methodological and interpretative issues would further solidify the conclusions and offer a clearer pathway for future interventions.--> Reviewer's Responses to Questions -->Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. --> Reviewer #1: Yes Reviewer #2: Yes ******** -->2. Has the statistical analysis been performed appropriately and rigorously? --> Reviewer #1: Yes Reviewer #2: Yes ****** -->3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.--> Reviewer #1: Yes Reviewer #2: Yes ****** -->4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.--> Reviewer #1: Yes Reviewer #2: Yes ****** -->5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)--> Reviewer #1: The manuscript is technically sound and the use of structural equation modeling (SEM) to analyze interrelationships is an advanced and appropriate choice for dealing with multiple variables and testing theoretical frameworks. Regarding English: in Table 2 there is text that is written in portuguese language. Please develop the limitation section including the reliance on self-reported data (e.g., food practices, screen time, and sleep duration) that may introduce bias or inaccuracies. Reviewer #2: I have reviewed your manuscript titled “Influence of study shift on the interrelationships among chronobiological factors, health practices, and anthropometry in adolescents.” The study investigates how school shift—morning versus afternoon—affects the complex interrelationships among sleep-related variables, chronotype, screen time, physical activity, dietary practices, and anthropometric measures in adolescents. Using a cross-sectional design with a sample of 925 students aged 14 to 19, you collected data through an online questionnaire and anthropometric measurements. Structural equation modeling was applied to test six path models that explore direct, indirect, and total effects among the variables, with particular attention given to differences between the morning and afternoon shifts. Your findings highlight that factors such as sleep duration, chronotype, and screen time have distinct associations with food practices and body mass index by age, depending on the study shift. These results suggest that the timing of school attendance is an important environmental marker that should be considered in health interventions targeting adolescents. While your work is comprehensive and methodologically detailed, there are several aspects that could be strengthened. First, the cross-sectional design limits the ability to infer causality, which you acknowledge; however, further discussion on this limitation and its implications for interpreting the results would improve the manuscript. Second, the reliance on self-reported measures for variables such as sleep duration, food practices, and screen time introduces potential bias. It might be useful to discuss how these biases could affect your findings or consider supplementing the questionnaire data with objective measures in future studies. Third, although the formation of latent variables for food practices is innovative, the rationale behind the grouping of certain items—particularly the separate treatment of vegetables and fruits—could be explained more thoroughly to clarify why these items did not load with other healthy eating indicators. Additionally, while the structural equation models appear robust, a more detailed presentation of the model fit indices and any modifications made based on the “modification indices” would enhance transparency. In summary, your study provides valuable insights into the influence of school shift on adolescent health behaviors and nutritional status. Addressing these methodological and interpretative issues would further solidify the conclusions and offer a clearer pathway for future interventions. ****** -->6. 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PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org . Please note that Supporting Information files do not need this step.--> https://doi.org/10.1371/journal.pone.0322617.r002
Revision 1
22 Mar 2025 Author Response Dear Editor, We sincerely appreciate the insightful comments and constructive feedback provided by the reviewers on our manuscript titled "Influence of study shift on the interrelationships among chronobiological factors, health practices, and anthropometry in adolescents". We carefully considered all suggestions and have made substantial revisions to address the concerns raised. Below, we provide a detailed response to each comment, outlining the modifications incorporated into the Revised Manuscript using Track Changes. Additionally, we made necessary adjustments to align with PLOS ONE's style requirements. These include: - Replacing "Figure" with "Fig."; - Renaming all supporting information files, changing "Supplementary Tables 1, 2, and 3" to "S1, S2, and S3 Tables"; - Removing supporting tables from the main manuscript and submitting them as separate files. We appreciate the time and consideration given to our work and look forward to your further feedback and that of the reviewers. Best regards, The authors. REVIEWER 1 1. In Table 2 there is text that is written in Portuguese language. Response: Thank you for your feedback. We have corrected the text in Table 2, ensuring that all content is now presented in English as required. 2. Please develop the limitation section including the reliance on self-reported data (e.g., food practices, screen time, and sleep duration) that may introduce bias or inaccuracies. Response: Thank you for your feedback. We have revised the limitations section to provide a more detailed discussion of the potential biases and inaccuracies associated with self-reported data. These modifications can be found between lines 506–517. REVIEWER 2 1. The cross-sectional design limits the ability to infer causality, which you acknowledge; however, further discussion on this limitation and its implications for interpreting the results would improve the manuscript. Response: Thank you for your valuable feedback. In response, we have expanded the discussion on the limitations of our cross-sectional study design, addressing its implications for causal inference and interpretation of results. These revisions can be found between lines 491–492 and 499–505. 2. The reliance on self-reported measures for variables such as sleep duration, food practices, and screen time introduces potential bias. It might be useful to discuss how these biases could affect your findings or consider supplementing the questionnaire data with objective measures in future studies. Response: Thank you for your feedback. We have revised the limitations section to further elaborate on the potential biases associated with self-reported data and their possible impact on our findings. Additionally, we have acknowledged the value of incorporating objective measurement tools in future research. These adjustments can be found between lines 506–517. 3. Although the formation of latent variables for food practices is innovative, the rationale behind the grouping of certain items - particularly the separate treatment of vegetables and fruits - could be explained more thoroughly to clarify why these items did not load with other healthy eating indicators. Response: Thank you for your valuable observation. We recognize the importance of clarifying the separation of vegetables and fruits from other healthy eating indicators in the analysis. To address this, we have incorporated an additional explanation between lines 123 and 129. In our model, latent variables require at least three indicators. Although fruits and vegetables were initially assigned to the same factor in the exploratory factor analysis, they formed a group with only two variables, making it methodologically inadequate to create a latent variable. Therefore, they were analyzed separately in the structural equation model. Forcing fruits and vegetables to load into Factor 1, which comprises breakfast, lunch, dinner, and beans, did not yield meaningful results, as they did not present satisfactory factor loadings (≥ 0.3) in the confirmatory factor analysis for either school shift. This suggests that these variables had low correlation with Factor 1 and did not adequately represent its theoretical construct. A possible explanation for this result is the study's setting: the federal educational institution provides free, high-quality meals daily, which may contribute to lesser differentiation of fruit and vegetable consumption. Furthermore, unlike beans and main meals, fruits and vegetables may be consumed in different contexts, such as snacks, and their inclusion in main meals depends on individual habits and availability. This partly explains their allocation to Factor 3 instead of Factor 1. As a result, Factor 1 was renamed from "healthy food practices" to "complete meals," while Factor 2 remained "unhealthy foods," and fruits and vegetables were analyzed as independent variables. 4. While the structural equation models appear robust, a more detailed presentation of the model fit indices and any modifications made based on the “modification indices” would enhance transparency. Response: We appreciate your feedback. To improve transparency regarding the modeling process, we have clarified the description of the modification indices in the Statistical Analysis section of Materials and Methods (lines 229-232) and provided a more detailed description of the model fit indices in the corresponding results table (lines 283-290). These revisions ensure a clearer presentation of the methodological decisions taken and the robustness of the structural equation models. Attachments Attachment Submitted filename: Response to Reviewers.docx https://doi.org/10.1371/journal.pone.0322617.r003
25 Mar 2025 Decision Letter - Miray Budak, Editor Influence of study shift on the interrelationships among chronobiological factors, health practices, and anthropometry in adolescents PONE-D-25-00055R1 Dear Dr. Cintia Chaves Curioni, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice will be generated when your article is formally accepted. Please note, if your institution has a publishing partnership with PLOS and your article meets the relevant criteria, all or part of your publication costs will be covered. Please make sure your user information is up-to-date by logging into Editorial Manager at Editorial Manager® and clicking the ‘Update My Information' link at the top of the page. If you have any questions relating to publication charges, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Miray Budak Academic Editor PLOS ONE Additional Editor Comments (optional): Dear Authors, Thank you for your thorough and thoughtful revisions to your manuscript titled “Influence of study shift on the interrelationships among chronobiological factors, health practices, and anthropometry in adolescents.” Your responses effectively address the reviewers’ concerns, and the modifications have strengthened the clarity and rigor of your study. Notably, the expanded discussion on study limitations, particularly regarding self-reported data and cross-sectional design, adds valuable context to your findings. Your detailed justification for the latent variable structure and factor loadings enhances the transparency of your methodology. Additionally, the clarification of model fit indices contributes to the robustness of your statistical analysis. After reviewing the revised manuscript and your responses, I am pleased to inform you that I recommend acceptance of your manuscript for publication in PLOS ONE. Congratulations on this achievement, and we look forward to seeing your work published. Best regards, Miray Budak Academic Editor, PLOS ONE https://doi.org/10.1371/journal.pone.0322617.r004
Formally Accepted
Acceptance Letter - Miray Budak, Editor PONE-D-25-00055R1 PLOS ONE Dear Dr. Curioni, I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now being handed over to our production team. At this stage, our production department will prepare your paper for publication. This includes ensuring the following: * All references, tables, and figures are properly cited * All relevant supporting information is included in the manuscript submission, * There are no issues that prevent the paper from being properly typeset You will receive further instructions from the production team, including instructions on how to review your proof when it is ready. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few days to review your paper and let you know the next and final steps. Lastly, if your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. If we can help with anything else, please email us at customercare@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Miray Budak Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0322617.r005

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