Review Reports - Optimizing Vegan Nutrition: Current Challenges and Potential Solutions

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In my opinion, the manuscript entitled Current Challenges in Plant‐Based Nutrition by Marques-Lopes et al., aimed to describe the nutrients that could be identified in plant foods, propose possible solutions (improving soil fertility) and to emphasize the need to reconsider dietary reference that may be more appropriate for this new eating patterns. The review is well designed and structured.

I have some comments and suggestions as follows:

I would like to see a critical point of view of authors regarding the debated of eating only plant-based food or the need to have an equilibrate diet that also include animal food.
Also, please mentioned the disadvantages of following exclusively a plant-based diet such as the contents of pesticides, fertilizers and so on.
Please mentioned the limitations of the presents study and further researches that need to be explored.

Comments for author File: Comments.pdf

Author Response

1. I would like to see a critical point of view of authors regarding the debated of eating only plant-based food or the need to have an equilibrate diet that also include animal food.

Responde: Thank you very much for your comments. As you mentioned, the fact of having a plant based diet needs to be balanced with an adequate food selection, some of them enriched and the use of supplements, especially B12 and then if necessary other nutrients. Advising populations to eat less food of animal origin must also be accompanied by the risks involved and the need for meal planning and supplementation. Different studies that have been published throughout the life cycle shown that an only plant-based diet can lead to a lower intake of some nutrients. This fact is explained throughout the manuscript in the different nutrients as they are mentioned; however the authors have added a paragraph that summarizes what the reviewer has asked for (Lines 85-92 and 95-98)

Also, please mentioned the disadvantages of following exclusively a plant-based diet such as the contents of pesticides, fertilizers and so on.

Response: In accordance with your instructions, a paragraph on exposure to pesticides through consumption of plant foods has been added (lines 425-432). The authors have carried out a literature search on this issue and found different results depending on the study, as it depends on whether the adhesion is through conventional or organic agriculture.

Please mentioned the limitations of the presents study and further researches that need to be explored.

Response: This article is intended as a wake-up call on the unresolved problems of plant-based diets, especially at the systemic, community and food chain levels. If the population is advised to exclude foods of animal origin, consumers should be aware that they should pay attention to nutrients that plants do not have, or have a very low amount. The limitations and further studies are presented in the lines (507-516). The main limitations of this work are that it does not focus specifically on any particular aspect of plant-based diets, and that it presents some ideas and points that need further research. More studies are needed on: the bioavailability of some nutrients in plant foods to support new recommendations for nutrient intakes in plant-based diets, as recommendations for mixed diets cannot be transferred to plant-based diets. Finally, more technological feasibility studies are needed for the introduction into the food chain of plant foods with higher nutritional value, either with fortification or with food production itself.

Reviewer 2 Report

Comments and Suggestions for Authors

This review covers an interesting topic of current lifestyle about the challenges in plant-based nutrition. The text is well-written and structured. However, there are some parts that need clarification and improvement in order to publish this study. Please see my specific comments below.

-Line 2 (Review Title): In case you want to focus on both vegan and plant-based diets, you should also include the word "vegan" in the title. If you include the latter word in the title, the main text of the whole review should clearly explain the differences between the two terms (vegan and plant-based) and cover both cases.

-Section 2.1: Add a Figure with the chemical structures of the main omega-3 fatty acids and comment on the molecules' biological properties based on the structural characteristics.

-Section 2.2: Add a Figure with the chemical structures of vitamin A and its precursors and comment on the molecules' biological properties based on the structural characteristics.

-Section 2: Please provide the main metabolic pathways/reactions for each nutrient category you've mentioned (i.e. omega-3 fatty acids, vitamin A, iodine and selenium) through which they are metabolized and affect human health. Use the latter info to better highlight the problems of their absence from the plant-based diets.

-Lines 373-374 (Table 1): Please be specific on the Table title, you mean the "European Union" legislation.

-Section 3: You need to validate your proposal with other investigations/studies, do not just write ideas. For example, give more information on current ways to achieve biofortification of selected crops on specific nutrients. What other have done on this matter? In lines 376-379 you make general comments about several food-processing practices. This is not specific. Please be more descriptive about the industrial protocols, instrumentation, processing conditions etc.. Follow this approach to the whole section. This is the most critical section of your work and should be supported by scientific evidence to provide a solid basis for you proposals.

-Table 3: (a) For α‐linolenic acid (ALA) is unclear in which column the content belongs; it seems a mixed text between the columns "Reason" and "Values". Also, use better titles for these columns. E.g. the "Value" corresponds to DRI or something else?; What do you mean by the word "Reason", maybe "effects of nutrient absence" or something more specific? (b) The Table is very simplified, missing important information. You must add a column that gives the concentration range of the nutrients in each of the main food sources. Also, discuss the Table with more criticality within the main text, highlighting with much clarity the pros and cons. For example, could you say that the concentration of nutrient X in food Y is 10-fold lower than the RDA and/or the RDA in nutrient X could be covered by combining food Y and food Z?

-References: More recent and innovative references could be also included to increase the validity of your work and its connection to recent advances.

Author Response

Thank you very much for your comments. Please let the authors explain to you what the objective of this article is: it is not to delve into a certain aspect, but to draw attention to points that are not resolved at the level of public health and food production. If governments are urging the population to reduce the consumption of foods of animal origin, the nutritional and dietary recommendations of governments must take into account the deficiencies and the food production system must provide plant foods with more nutrients. The authors wanted to give a general perspective of this aspect; in fact, it is the first article that brings together all the aspects.

Response: The authors have not intended to direct the article towards the vegan diet, we consider that all plant based diets (and more accentuated the vegan diet) need to solve some points at a systemic, public health and food production level. When some nutrient is especially absent or in very low quantity in the vegan diet on the basis of the previous studies, we have already named it. Also, there are already quite a few studies that report the differences between vegetarian and vegan diet types. The authors expose some of them and intend to call attention to a more comprehensive view of the issue.

-Section 2.1: Add a Figure with the chemical structures of the main omega-3 fatty acids and comment on the molecules' biological properties based on the structural characteristics.

Response: The authors already refer to studies on the chemical basis and physiological properties of omega-3, vitamin A, iodine, selenium, etc. and their lack in the diet. There are already several studies reporting this. We consider that this is not the objetive of this article. The objective of this article is to review those nutrients that may be missing when the population is told to take less food of animal origin, and that the institutions of public health, food safety and the food industry should take into account so that there is no deficiency at the population level.

-Section 2.2: Add a Figure with the chemical structures of vitamin A and its precursors and comment on the molecules' biological properties based on the structural characteristics.

Idem, 2.1

Idem, 2.1.

-Lines 373-374 (Table 1): Please be specific on the Table title, you mean the "European Union" legislation.

Response: The Table title was corrected

Indeed, this is a topic that was missing from the manuscript. We have expanded this part with related articles. The authors have added information regarding the fortification of selected crops on specific nutrients (lines 333-362).

Response: Table was corrected. The values in the table are recommendations proposed by different authors, they are not official recommendations, which is why we have included them in this table to draw attention to the fact that the official recommendations (RDI's) should be reconsidered.

Likewise, the table is intended to be a compilation of points to draw attention to the fact that some recommendations should be reconsidered. There are already publications on the nutrient content of these foods, that is not the objective of this publication.

-References: More recent and innovative references could be also included to increase the validity of your work and its connection to recent advances.

Response: The authors have done a review of the literature, many of the studies are already cited in this article, others have been included in this new version, especially those related to biofortification.

Reviewer 3 Report

Comments and Suggestions for Authors

applsci-3726808-peer-review-v3

The authors present a review study of the nutritional efficacy of plant-based food. While the topic is interesting, the title is not the best to describe the content. Plant-based food is a large domain, and the manuscript only covers the broad context of the topic without going deeper into processed food and the effect of different processing methods, especially extrusion, on the nutrition of plant-based food. The title should be changed to a more representative one that shows the challenges and how they are managed. More importantly, these challenges are linked to the vegan diet. This should be reflected in the title.

The authors should add a paragraph of different diets (vegan, vegetarian, pescetarian, etc.,) and state a reference diet to compare with the plant-based.

The authors must add a table of contents, a list of abbreviations, and acronyms. Some abbreviations were not defined, such as EPA, and DHA. This is not acceptable, even if they are known to those who work in the domain, they are not to others.

Figure 1 does not satisfy the purpose it should. You need to modify the figure to be more self-explanatory, such as adding a heading for each of the system, optimisation method, and effect.

A similar figure should be created to better explain section 2.

The authors should add a section about their view of how the plant-based food industry can adapt to the nutritional challenges in a way that makes such food more desirable by consumers. This is not about fortification, but more into novel processing technologies such as 3D printing.

Author Response

Point-by-point responses to the reviewer

Dear reviewer

Thank you for your comments. The authors have addressed all the points you mentioned. We appreciate your suggestions and hope we have addressed what you mentioned. Revisions and changes are marked in red. In addition to addressing the reviewer's suggestions regarding the title, figures, tables, and requested text, the authors changed the abstract and have revised and the entire article, So some parts of the text have been changed.

COMMENT #1. The authors present a review study of the nutritional efficacy of plant-based food. While the topic is interesting, the title is not the best to describe the content. Plant-based food is a large domain, and the manuscript only covers the broad context of the topic without going deeper into processed food and the effect of different processing methods, especially extrusion, on the nutrition of plant-based food. The title should be changed to a more representative one that shows the challenges and how they are managed. More importantly, these challenges are linked to the vegan diet. This should be reflected in the title.

RESPONSE #1: The authors have changed the title to more accurately reflect the article. This manuscript seeks to comprehensively present the different challenges presented by removing animal-based nutrients from the human diet, especially, and as the name suggests, the vegan diet. The authors aim to provide a general perspective of the parties involved. In fact, to our knowledge, this is the first article to name the different challenges posed by a plant-based diet, that is, from the nutritional aspect to the industrial fortification of food or soil at the agricultural level. This aims to be is a comprehensive approach to draw the attention of the different agents involved in human nutrition in order to "close the loop," that is: addressing nutritional challenges in plant-based and specially vegan diets naming agricultural, industrial, and household solutions. The new proposed title is “Optimizing Vegan Nutrition: Current challenges and potential solutions”.

COMMENT #2: The authors should add a paragraph of different diets (vegan, vegetarian, pescetarian, etc.,) and state a reference diet to compare with the plant-based.

RESPONSE #2: The authors understand that as a reference diet, you name the so-called "mixed diet" adopted by EFSA or “omnivorous diet”. We have included a paragraph (lines 40 to 50) referring to the omnivorous diet, the different plant-based models, and also mentioned the new diet models linked to good overall health indicators, although we have then focused more on the vegan diet, which is the one that actually has the most food and nutrient restrictions.

COMMENT #3: The authors must add a table of contents, a list of abbreviations, and acronyms. Some abbreviations were not defined, such as EPA, and DHA. This is not acceptable, even if they are known to those who work in the domain, they are not to others.

RESPONSE #3: We appreciate your suggestion and apologize for the omission of the description of abbreviations and terms. It is very important that the text can be understood by both experts and non-experts in the field. In order to fulfilling your request and if you agree, instead of including a table, we have reviewed the entire text and spelled out the abbreviations and clarified the terms, as other authors in the field do. Since some of the terms were written in full and others were not, we have written them all throughout the text, where appropriate, instead of placing them in a table.

COMMENT #4: Figure 1 does not satisfy the purpose it should. You need to modify the figure to be more self-explanatory, such as adding a heading for each of the system, optimisation method, and effect. A similar figure should be created to better explain section 2.

RESPONSE #4: In accordance with your suggestions, we have revised Figure 1. To provide a more comprehensive summary of Section 2 we have done the Figure 2. We have also modified Table 3 to be more consistent with the information in Figure 2.

COMMENT #5: The authors should add a section about their view of how the plant-based food industry can adapt to the nutritional challenges in a way that makes such food more desirable by consumers. This is not about fortification, but more into novel processing technologies such as 3D printing.

RESPONSE #4: In accordance with your instructions, we have added information about emerging meat alternatives. The authors mentioned the three major technological approaches driving innovation in sustainable protein production which are: cultivated meat, fermentation-derived proteins, and 3D-printed protein structures (lines 470 to 487).

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Some issues were addressed. However, the response to most of the comments was superficial and based on the avoidance of additional work to improve the article. This is supposed to be a "Review" article that the authors want to publish in a reputable journal with impact factor. Please be familiar with recent reviews. The content should cover ALL aspects, including the metabolic traits that lead to the claimed health benefits. It's scientifically improper to publish a review article that discusses the content of beneficial compounds/nutrients without providing in the form of Figures their chemical structure as well as some main metabolic pathways during their intake. A review article should be thorough and cover a variety of aspects that highlight the importance of optimizing the health-beneficial nutrient content. Also, the discussion on the industrial technologies advantages, disadvantages and innovations lacks depth. There should be more details on the mechanistic aspects and their effect on the composition. Please do not respond again with the simplified claim that this is not the purpose of your study. You are writing a "Review" article in the year 2025, the standards are high and the purpose is to be comprehensive covering all the aspects of the topic. You claim that the targets of the review were (a) "public health" without illustrating the health-associated mechanisms of action as well as (b) the "food production" by mentioning the names of the technologies and some key points in a few paragraphs. The health-beneficial effects of the required nutrients should be addressed with more depth and the current food production technologies should be discussed in much more detail. Do not forget that this is a review, not a research article.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The authors addressed most of the points listed in the first review round. However, the following must be addressed for the paper to be accepted for publication:

Lines 40-51: only one reference is not enough.
Figure 2 should be a table.
Bullet points are not preferred to be stated in the Conclusions.

Author Response

Point-by-point responses to the reviewer

Dear reviewer

Thank you for your comments. The authors have addressed all the points you mentioned. Changes are marked in red.

COMMENT #1 Lines 40-51: only one reference is not enough.

RESPONSE #1: Three new citations have been included (marked in red, referring to the information in lines 40 to 51). This paragraph is now cited with four relevant references for that text.

COMMENT #2: Figure 2 should be a table.

RESPONSE #2: Figure 2 has been converted into a table, and the numbering of the tables has been adjusted.

COMMENT #3: Bullet points are not preferred to be stated in the Conclusions.

RESPONSE #3: The bullet points have been removed from the Conclusions.