Knowledge of health benefits, availability, accessibility and consumption of indigenous foods by urban adults in the Cape Metropole, South Africa

Tasneem Johnson; Mthokozisi Zuma; Laurencia Govender; Nelene Koen; Xikombiso Mbhenyane

doi:10.1371/journal.pone.0333306

Peer Review History

Original SubmissionNovember 27, 2024
31 Jul 2025 Decision Letter - Edwin Hlangwani, Editor Dear Dr. Mbhenyane, 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. Please submit your revised manuscript by Sep 14 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. 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'. 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If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? Reviewer #1: Yes Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? -->?> Reviewer #1: Yes Reviewer #2: I Don't Know ****** 3. Have the authors made all data underlying the findings in their manuscript fully available??> The PLOS Data policy Reviewer #1: Yes Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English??> Reviewer #1: Yes Reviewer #2: Yes ****** Reviewer #1: Knowledge of Health Benefits, Availability, Accessibility, and Consumption of Indigenous Foods by Urban Adults in the Cape Metropole, South Africa The manuscript is well written and sounds very interesting. However, the researchers may need to consider some of the following comments and suggestions to improve the paper. Some aspects of the paper are unclear, such as the difference between formal and informal supermarkets among the surveyed supermarkets. I think the type of supermarket may influence the food found, either exotic or indigenous. This is because various food products have different storage and transportation requirements. As a result, most informal supermarkets, particularly those owned by individuals in communities, lack the proper infrastructure to store certain food products, particularly perishable and semi-perishable products, which may lead to a poor supply of such products, regardless of whether they are IFs. Another critical aspect was the distinction between income levels and the type of food items purchased among the participants. In most cases, affordability plays a crucial role in influencing buying patterns among communities; hence, the buying power in a given community also plays a part in determining the type of shops or supermarkets you could find. This is because low-income earners are most likely to buy key food products necessary to sustain them throughout the month, instead of purchasing healthy food products. Therefore, understanding the buying patterns based on income levels could help us understand why specific households prefer certain food products over others, particularly indigenous products over exotic ones. Furthermore, the study does not clearly explain the nutritional benefits of the IFs compared to the exotic ones readily available or accessible in the area or supermarkets using literature. Without the link between the IFs and their alternative foods offering similar benefits, it may be hard to say the participants prefer certain products over others, particularly if such products are not even related or used in place of each other, such as eating apples instead of guava. I think the products need to be comparable or offer the same benefits for one to say they prefer one over the other. Also, a link between the available IFs and their role in addressing malnutrition and non-communicable diseases, including their health benefits, would help show the health risks that could arise from the communities' eating habits. Abstract Lines 29-32 – the background highlights the role played by different indigenous foods in addressing several problems, including diseases. Still, the food products covered in the study could not be linked to the above issues in the discussion. Line 33-35 – the aim mentions knowledge on the preparation and cooking of indigenous foods, but the study doesn't show any evidence of such a section being covered anywhere throughout the results. Line 47- 50. The study's conclusion sounds too broad based on what was covered in the survey. I think the conclusion needs to align with the aim of the study, which will indicate if the surveyed communities possess the correct knowledge around the benefits of indigenous foods and the access or availability thereof. Now it's not clear if the potential is not realised because they don't consume the food or because they don't know its benefits. Introduction Line 64 – 113 correct sampling of district "sampling od districts," Sampling Line 114 correct that would be used for the piloting to “that was used” Sample size Line 152 – be consistent, write ten percent in numbers and symbols DISCUSSION What makes the IFs better than the exotic foods, given that urban communities already buy exotic commodities, which could offer the same benefits? It would be better to promote the IFs so that the population can plant their own instead of just promoting that they buy the other in place of the other, unless the indigenous foods are cheap but overlooked due to a lack of knowledge. Indigenous food availability Since IFs play a significant role in reducing non-communicable diseases, were the assessed IFs part of the important ones or not? If not, then what does that mean about the population in the area, particularly as far as diseases are concerned? What foods were planted in home gardens? There were no signs of IFs, and some gardens had IFs. Limitations of the study Maybe an explanation around the supermarkets used, if they were formal or informal supermarkets, such terminology would help one to have a clear picture of the establishments used for the study, or the difference thereof. This needs to be clarified under methodology. The IFs used might have been influenced by access, since only starch was available, with no vegetables. This could speak to the supermarket's standards and storage conditions for certain food Items. Other IFs are highly perishable; hence, many food stalls or supermarkets shy away from purchasing them to avoid wastage. Conclusion and recommendation To overcome economic burden, people are bound to buy essential food products and never worry about their health benefits. Considering that the participants were at various income levels, was there any difference in their buying patterns, such as buying more health foods than their counterparts? This does not come up under discussion. Maybe a comparison between the IFs and exotic foods in terms of which they buy or eat in place of what IFs will help us understand if buying such foods is influenced by knowledge or its purely accessibility. Also, comparing prices will help us understand why they went for expensive, exotic foods over cheap, healthy ones. There's no link between the available IFs and their role in addressing malnutrition and non-communicable diseases, including their health benefits. Such a discussion will help us understand the health risks of the population. Reviewer #2: Dear Author, Thank you for submitting your work for consideration for publication in PLOS One. The manuscript is relevant and sound, however, corrections will be needed to improve its quality. Below are my comments and suggestions: (1) Abstract, very sound (2) Introduction, it is sound, however, authors must introduce IFs to the reader, what are they, nutritional composition, phytochemicals, examples of IFs in South Africa, and their contribution to the livelihood of households. Furthermore, previous studies done on IFs in South Africa should be included to show the knowledge gap and novelty of the current study. The objective of the study must be clear on line 81. (3) Methods, line 84 is not clear since authors indicated that the aim is to develop a profile of the status of IFs amongst adults between 18 and 80. How are they going to develop the profile? The statement must be revised. Line 96, remove "of the Cape Metropole" since it is a repetition of the previous line. Line 112, change "od" to "of districts". Line 114, is it "would be" or "was"? The same comment is applicable for lines 129 and 133. (4) The interpretation of the results is very sound. (5) Discussion, under indigenous food availability, authors should expand the discussion and explain the reason(s) for butternut, maize meal, samp and beans, samp and white-fleshed sweet potato as the most widely available IFs. The same is applicable for green leafy vegetables not featuring with regards to availability in this study. Otherwise, the discussion is very sound with scientific tone. (6) Limitation of the study and conclusion, they are very sound. ****** what does this mean? ). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? 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Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0333306.r001
Revision 1
27 Aug 2025 Author Response 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 Response: We have ensured that the manuscript is complaint. 2. Please note that funding information should not appear in any section or other areas of your manuscript. We will only publish funding information present in the Funding Statement section of the online submission form. Please remove any funding-related text from the manuscript. Response: Funding details have been placed in appropriate sections. 3. We note that you have indicated that there are restrictions to data sharing for this study. PLOS only allows data to be available upon request if there are legal or ethical restrictions on sharing data publicly. For more information on unacceptable data access restrictions, please see http://journals.plos.org/plosone/s/data-availability#loc-unacceptable-data-access-restrictions. Response: The University of Stellenbosch requires that the following is completed and approved by the Health Research Ethics Committee (HREC) before sharing data. HREC MTA/DTA requirements, processes and term sheet: • Material Transfer Agreement (MTA) and Data Transfer Agreement (DTA) HREC requirements and processes • Data Transfer Agreeement (DTA): Guidance for Researchers • HREC Termsheet: Material/Data Transfer Agreement Data will be made available following the University policies upon request. Before we proceed with your manuscript, please address the following prompts: a) If there are ethical or legal restrictions on sharing a de-identified data set, please explain them in detail (e.g., data contain potentially identifying or sensitive patient information, data are owned by a third-party organization, etc.) and who has imposed them (e.g., a Research Ethics Committee or Institutional Review Board, etc.). Please also provide contact information for a data access committee, ethics committee, or other institutional body to which data requests may be sent. Response: Data requests may be sent to the corresponding author who is the data owner and will ensure compliance with the University policies for access as noted above. In addition, please note that in terms of the Protection of Personal Information Act No. 4 of 2013 of Republic of South Africa, Signed into law: 19 November 2013, published in the Government Gazette: 26 November 2013, Commencement dates: Full enforcement began on 1 July 2021b) there are also restrictions providing names of individuals of the Institutions other than committee details. Here is the contact details of HREC. http://www.sun.ac.za/english/faculty/healthsciences/rdsd/Pages/Health-Research-Ethics.aspx b. If there are no restrictions, please upload the minimal anonymized data set necessary to replicate your study findings to a stable, public repository and provide us with the relevant URLs, DOIs, or accession numbers. For a list of recommended repositories, please see https://journals.plos.org/plosone/s/recommended-repositories. You also have the option of uploading the data as Supporting Information files, but we would recommend depositing data directly to a data repository if possible. Response: Not applicable. 4. We note you have included a table to which you do not refer in the text of your manuscript. Please ensure that you refer to Table 3 and 4 in your text; if accepted, production will need this reference to link the reader to the Table. Responses: The comment has been implemented. It is actually Tables 2 and 3, and these have been referred to in the text and it is highlighted. 5. If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise. Response: The manuscript has been reviewed to ensure all citations are relevant. Attachments Attachment Submitted filename: PONE-D-24-41163_Rebuttal letter.docx https://doi.org/10.1371/journal.pone.0333306.r002
8 Sep 2025 Decision Letter - Edwin Hlangwani, Editor Dear Dr. Mbhenyane, 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. The authors have satisfactorily addressed the reviewer comments. The data presentation is adequate but I am concerned it will be a dry read as there are no Figures to complement the Tables. Under study design - include coordinates of the "Cape Metropole". Some kind of map would also be useful Under data analysis - Delete "Quantitative data was captured into a Microsoft Excel spreadsheet and cleaned by the principal investigator." - Specify the name, and version of the statistical software used. Please submit your revised manuscript by Oct 23 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. 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. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. 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, Edwin Hlangwani, PhD Academic Editor PLOS ONE Journal Requirements: If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise. 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. [Note: HTML markup is below. Please do not edit.] [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/ . 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.0333306.r003
Revision 2
9 Sep 2025 Author Response Monday, 08 September 2025 Rebuttal letter The responses are presented below each point . 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. Response: The authors have satisfactorily addressed the reviewer comments. The data presentation is adequate but I am concerned it will be a dry read as there are no Figures to complement the Tables. Response: Under study design - include coordinates of the "Cape Metropole". Some kind of map would also be useful Response: Under data analysis - Delete "Quantitative data was captured into a Microsoft Excel spreadsheet and cleaned by the principal investigator." Response: - Specify the name, and version of the statistical software used. Response: Attachments Attachment Submitted filename: PONE-D-24-41163_Rebuttal letter_09 September 2025.docx https://doi.org/10.1371/journal.pone.0333306.r004
12 Sep 2025 Decision Letter - Edwin Hlangwani, Editor Knowledge of Health Benefits, Availability, Accessibility and Consumption of Indigenous Foods by Urban Adults in the Cape Metropole, South Africa PONE-D-24-41163R2 Dear Dr. Mbhenyane, 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. For questions related to billing, please contact billing support . 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, Edwin Hlangwani, PhD Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0333306.r005
Formally Accepted
Acceptance Letter - Edwin Hlangwani, Editor PONE-D-24-41163R2 PLOS ONE Dear Dr. Mbhenyane, 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. You will receive an invoice from PLOS for your publication fee after your manuscript has reached the completed accept phase. If you receive an email requesting payment before acceptance or for any other service, this may be a phishing scheme. Learn how to identify phishing emails and protect your accounts at https://explore.plos.org/phishing. 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. Edwin Hlangwani Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0333306.r006

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