Review Reports - Assessment of the Nutritional Composition and Environmental Impact of Menus Served in a University Cafeteria During an Academic Year

Round 1

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

Please find my following observations:

The abstract is a concise summary of the research conducted in this study. One of the current challenges for science is to provide those involved in the food system with information and solutions to understand and mitigate the carbon footprint and to influence consumer choices in this regard.

The authors present in the Introduction, in a concise way, what are the key points of the research and its purpose. As the authors mentioned, with references from the literature, livestock-based products' carbon footprint is much larger than that of plant-based products. An observation related to the abbreviation for carbon footprint - why did the authors prefer CFP instead of CF, as is usual in the literature?

Materials and Methods. The section is properly presented.

Lines 104-112: The authors mention how they estimated CF for the university cafeteria menu. Can the authors estimate more widely regarding the CF estimation of foods, and what are the limits regarding the choice of values?

For example, Röös, Elin (2013) demonstrate the CF uncertainty of some food products from a well-defined geographical area to be within ±10-30%, indicating that the CF uncertainty for more complex foods or foods with a more non-specific origin is considerably higher (https://publications.slu.se/?file=publ/show&id=51919).

Results

The nutritional value was estimated for the first and second courses, grouped by the main ingredient presented in Figure 1.

Is the value of the 6478 combinations of first and second courses (plus the other components) mathematically calculated or was it identified based on the choices of the study participants?

Discussion

To communicate the obtained results, can the authors suggest a nutritionally balanced plate model with a reduced CF footprint? I can suggest a reference from the specialized literature (just for example): Yrjö Virtanen, Sirpa Kurppa, Merja Saarinen, Juha-Matti Katajajuuri, Kirsi Usva, Ilmo Mäenpää, Johanna Mäkelä, Juha Grönroos, Ari Nissinen, Carbon footprint of food – approaches from national input–output statistics and a LCA of a food portion, Journal of Cleaner Production, Volume 19, Issue 16, 2011, Pages 1849-1856, ISSN 0959-6526, https://doi.org/10.1016/j.jclepro.2011.07.001.

Author Response

Please see the attachment. Thank you.

Author Response File: Author Response.docx

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

This manuscript was very interesting as it considered nutrition and environmental impact. I have questions.

Line 80-82: The garnishes, bread and desserts were weighed daily, 10 units of each, as the weight didn’t vary substantially, and the average value obtained for each of them was used for nutritional assessment. For how many days did you repeat the weighing process?

Did you get consent from the study participants?

Comments on the Quality of English Language

The language needs some improvement.

Author Response

Please see the attachment. Thank you.

Author Response File: Author Response.docx

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

This study provides an assessment of the nutritional composition and the impact of menus served in a university cafeteria during an academic year. The authors collected data from 79 first courses and 82 second courses to determine the nutritional composition of the various menus offered at the cafeteria of the university assessed, giving raise to about 6500 possible combinations. The results provided in the study indicate the the average caloric intake was about 1200 kcal/menu, with a high consumption of proteins and lipids. It is the conclusions of the authors that the information provided in this study can be used effectively by specialists in the field as well as in education to create appropriate food delivery that balances caloric intake with micronutrients and macronutrients intake in students using university's cafeteria.

Author Response

Thank you very much about your comments.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have considered the need to determine the nutrition and environmental sustainability of food choices. This is an important area.

Introduction: Provides some context to the challenges of measuring the environmental aspects of dietary choices. It is not clear on line 48 why plant products make for an 'interesting' option. Suggest the authors reword.

Line 48/49 then introduces food security which seems a different premise than the aim of the paper.

End of the introduction: There are no objectives listed for the study. Line 57 indicates that it might be measuring the choices of students, but this is not clear in the methods. The paper would benefit from specific objectives at the end of the Introduction.

The study involves an observation of meal service at a University cafeteria. It is not clear in 2. Materials and methods how the study design was employed? The abstract mentions a cross-sectional-observational-descriptive design (line 13) but this is not explained in the methods.

As an observational study was it the meal choices of the students is being observed or the authors are weighing and taking photos of servings that have been pre-portioned?

Line 63-73 It would be useful to have a table describing the first and second courses as this is not typical lunch in all countries. It is difficult to interpret the results such as Figure 1 and Table 1. Is the university lunch service free in Spain? Contextual information would assist the reader to know the potential for dietary choices by students.

Line 75- Is it one weighing of each option to the total of 10 or for each option a serving was weighed 10 times? Is there any methodological precedent for how the figure of 10 was decided?

Line 85- It is not clear how the menu components were evaluated to calculate nutrient composition. Were the recipes used by the kitchen staff sourced?

Line 105 indicates a final step to observe environmental impact, however the authors are only able to correlate GHG estimations with nutrient analysis? What % of foods had no published or available GHG impact? The Results shows section 3.1 nutrients and section 3.2 environmental impact without any analysis of the two aspects together.

Line 106 indicates use of reference 22 for supporting the calculation of GHG emissions for different components of the menu, but reference 22 in the list is a 2002 publication on dietary reference intakes which does not seem correct.

Figure 1- The presentation of food types/meals is confusing which is why having a clear description of the menu items would assist in the methods section. Line 141 Table 1, it is not easy for the reader to remember what is a first course and what is a second course to interpret this table.

Line 141 and the text previous to Table 1 seem to indicate comparison to recommended dietary intakes, but it did not seem to be the aim of the paper to do this comparison. This seems to be based on an assumption that a student would eat all the food/meal options.

Section 3.2 Provides one table with average co2eq but the important point is the combinations of courses and other choices a student could make. It is not clear what is the maximum to minimum Co2eq that could be consumed from what combinations. It would be useful to have a table to show what combinations of meals/food choices produce high environmental impact. It is not particularly novel that meals with animal origin products were generating a higher CFP. These meal combinations might also have been providing high nutrient intakes?

Discussion

As the results are difficult to interpret because more detail is required in the methods, it is not possible to interpret the discussion well.

Lines 225 to 227 do not state the significance of the findings but only reiterating the purpose of the study.

There is one paragraph in the discussion on nutritional assessment (Line 229 to 242) but there is nearly two pages (line 243 to 335) on the environmental impact.

I suggest the authors rework the discussion as there are several short paragraphs that seem to be just rephrasing what other studies found. There needs to be a focus on what is novel about this study.

Comments on the Quality of English Language

The paper has some instances of where English language could be improved. For example, the abstract, line 19 and 20 'summon' I think is meant to be 'sum of'.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

Thank you for the opportunity to review this interesting manuscript entitled “Assessment of the nutritional composition and environmental impact of menus served in a university cafeteria during an academic year”.

The issue represents a challenge under many perspectives. The topic is well presented, and all sections are well organized. I agree with most of the points indicated in the manuscript and, in the meantime, I believe there will be some valuable discussions about it in the future.

Please accept my most sincere appreciation for your contribution.

Good luck!

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The authors measured the nutritional content and carbon footprint for the population of possible meals that might be served in one university cafeteria over the course of an academic year. In their Results, they give information about the energy contributions of meal components and information about the extent to which these meals satisfy protein, fat, and micronutrient requirements. They also provide information about the mean carbon footprint of various components of these meals. The authors suggested that nutritional content and sustainability be considered in constructing menus and that diners be advised to consider these two aspects of the food they choose.

This research and analyses of data appear to have been competently done. It might have been nice had the authors gone farther with what they present, but that may not be necessary.

Here are some specific comments:

1. There are places in which the English used is nonstandard and/or is difficult to understand. For example, it is not clear what the word “summon” means on lines 17 and 19. What the authors are trying to say in the last couple of paragraphs of the introduction is not totally clear. What is being communicated in the paragraphs on lines 148-152 and on lines 159-162 is not clear.

2. It would be helpful if the authors would state clearly their central question at the end of the introduction.

3. As their “Data Availability Statement”, the authors say that “Data are contained within the article”, but they are not. The article contains only summary statistics. Do the authors plan to deposit their raw data in a depository to which there will be public access (e.g., the Open Science Framework)? If not, why not?

4. Should the percentages for lipids, proteins, and carbohydrates in Table 1 add to 100%? (They don’t.)

5. There appear to be unnecessary headings on line 185.

6. Zinc W is in Table 2 in two places. One of these should be Zinc M.

7. Concerning going further: The authors make suggestions about eating healthy and sustainable foods, but don’t make specific recommendations about how to balance these factors or provide analyses of how these factors are related. Is there a way to score individual foods or dishes on both some nutritional measure and sustainability? Could dining services provide sustainability information about menu items? Would that influence choices? The manuscript could have more impact if more specific actionable recommendations were made.

Comments on the Quality of English Language

Although the authors' English is vastly better than my Spanish, the manuscript would benefit from a complete read-through and editing.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for your revisions to your manuscript and responses to comments to improve the clarity of the manuscript.

The authors have provided 11 responses to comments on their first version of the manuscript but as there are not specifics provided as to what was changed and line number, I have done my best to interpret the usefulness of the changes for improving the manuscript.

I have focused on the methods and the results presentation.

2. Materials and methods

Line 71 Indicates the time frame of the academic year of 2019-2022, how many days was this and none of the data collection days were impacted by COVID-19?

Line 74 to 77 The content of the courses is still not clear, the authors indicate main ingredients but sometimes list a type of food, such as a second course could be cake or a type of cooking/presentation method such as skewers. Garnishes are not listed here but are described as part of the menu in line 78/79.

The authors have indicated in their response that the lunch service in Spain is not free, but is it a set price for all the components that is listed, first course, second course, garnish, dessert, bread, beverage. It is likely that students would take all this food due to the price and potentially is some of this food wasted? More context needs to be provided for readers outside of Spain or not familiar with the university cafeteria operation.

Line 80 Are the side options with the second course- not listed on Line 72 which describes the daily lunch menu. The side options are the choice of the student?

Line 86 indicates that 1- weighing and photographs were taken of each option in first and second courses, but Line 74 indicates there are four first courses and three second courses- which is 12 combinations? The dessert, bread, and beverage options were then not considered? It is not clear if the 10 chosen were those as served by students and if there was a random pattern of selecting the 10 or just using the first 10 served for the lunch meal, cafeteria staff, students or the research team? If it was students, did all students choose the full menu, first, second course, dessert, garnish, bread and beverage?

Line 86 Why was it necessary to weigh the options in the first and second courses, were these not pre portioned or pre-sliced. The objectives on line 62 indicate that an objective was the evaluation the nutritional contributions of the menus that were served (indicating by staff) but then goes onto describe young adults choices. Can the authors make it clear who was selecting the dishes that were being weighed and photographed. If students, did they have to consent to having their food photographed?

Line 93 Were the recipes from the kitchen collected for the analysis? The authors have provided detail in their response to the reviewer but not translated this into the manuscript detail.

Line 95 There was no weighing and photos of the respective garnishes, bread, desserts, beverages and dressings for the entire menu. Who made the decision on what was being selected?

Results

Line 127, if the weighing included both first and second courses, why is there only 79 first and 82 second courses. It is still not clear how then the other menu items such as garnish, dessert, bread and beverages were assessed and included in the results.

Figure 1 Is cut off and not showing probably- This figure is to show the main ingredient yet one of the options is ‘precooked’ 5%.

Table 1 indicates the average energy contributions, but garnishes, dessert, bread, beverages and desserts were not weighed as part of the analysis. The methods section needs to describe in more detail how these were assessed to establish serve size and ingredient content.

Line 171 Indicates the first and second courses were in the appropriate caloric range for the midday meal. While EFSA is mentioned in the methods, the analysis methods indicates calculating quartiles not benchmarking against a caloric range for a midday meal. The kcal levels presented on Line 175 would appear to be for a whole day? Can the methods be clearer on how the total kcal were calculated and benchmarked. For example, in Table 1 the Men % and Women % is of their recommended daily kcal?

The remaining nutrient analysis from Line 182 seem only for the first and second courses as these were the only parts of the lunch service weighed? Same with Table 3 and 4? Therefore, the majority of the results are not from the entire menu but just the first and second course combinations?

3.2 Environmental impact assessment

Line 250-252 is part of the introduction- the results should just state the findings. The Introduction does not mention the 2020-2030 Agenda and Sustainable Development Goals. Can the authors describe what is specifically in these documents that indicates which foods are more sustainable than others?

Comments on the Quality of English Language

Improved but still some instances where the intent of the sentence is not clear.

Author Response

Thank you for your revision and comments. We have tried to improve the manuscript according your suggestions and we are very thankful about them.

Materials and methods

- Line 71 Indicates the time frame of the academic year of 2019-2020, how many days was this and none of the data collection days were impacted by COVID-19?

We collected data from the beginning of the academic year (September 9^th 2019) until the confinement due to the COVID-19 pandemic on March 13^th 2020. This period was sufficient to collect menu data for the different seasons

- Line 74 to 77 The content of the courses is still not clear, the authors indicate main ingredients but sometimes list a type of food, such as a second course could be cake or a type of cooking/presentation method such as skewers. Garnishes are not listed here but are described as part of the menu in line 78/79.

Meat/fish or eggs groups have a clearly identifiable majority component, while the precooked ones respond to processed products and the "other" group are dishes in which there is no clearly majority ingredient (meat/fish crepes, contain in addition to these ingredients the sauce, dough, vegetables, etc.).

Although the garnishes (vegetables, chips...) are part of the second course, the user can choose any of them. Including the garnishes in the second course would cause a more complicated classification of them, since the possible combinations would be tripled.

- The authors have indicated in their response that the lunch service in Spain is not free, but is it a set price for all the components that is listed, first course, second course, garnish, dessert, bread, beverage. It is likely that students would take all this food due to the price and potentially is some of this food wasted? More context needs to be provided for readers outside of Spain or not familiar with the university cafeteria operation.

The price includes all the components of the menu. The nutritional assessment of the complete menu and its environmental impact has been the object of this work, the possible food waste or the environmental impact of the food waste not evaluated.

- Line 80 Are the side options with the second course- not listed on Line 72 which describes the daily lunch menu. The side options are the choice of the student?

Yes, the diner or the students chose the garnish option according to their preference (indicated in lines 73-74).

- Line 86 indicates that 1- weighing and photographs were taken of each option in first and second courses, but Line 74 indicates there are four first courses and three second courses- which is 12 combinations? The dessert, bread, and beverage options were then not considered? It is not clear if the 10 chosen were those as served by students and if there was a random pattern of selecting the 10 or just using the first 10 served for the lunch meal, cafeteria staff, students or the research team? If it was students, did all students choose the full menu, first, second course, dessert, garnish, bread and beverage?

The dishes were prepared, photographed and weighed at that moment, before the students went through the self-service line and before they chose their menu. The garnishes, bread and desserts were weighed daily 10 units of each and the average value obtained for each of them was used for nutritional assessment.

The first 10 courses served from each of those offered each day were weighed.

All students choose the full menu, but for the present research we don’t assess the real intake of each student, we just analyze the nutritional value all the possible combinations of the menu.

- Line 86. Why was it necessary to weigh the options in the first and second courses, were these not pre portioned or pre-sliced. The objectives on line 62 indicate that an objective was the evaluation the nutritional contributions of the menus that were served (indicating by staff) but then goes onto describe young adult choices. Can the authors make it clear who was selecting the dishes that were being weighed and photographed. If students, did they have to consent to having their food photographed?

They need to be weighed because they are served by the staff before they are chosen by the diner, and there may be some variation in weights (it is the kitchen staff themselves who handle the dishes). Afterwards, diners choose the dish they want.

We have the consent from the UV ethics committee to carry out the analysis.

- Line 93 Were the recipes from the kitchen collected for the analysis? The authors have provided detail in their response to the reviewer but not translated this into the manuscript detail.

We have included in the manuscript the explanation about the recipes (line 93-94), as you suggest us.

- Line 95 There was no weighing and photos of the respective garnishes, bread, desserts, beverages and dressings for the entire menu. Who made the decision on what was being selected?

Thank you for your comment, we have included in the material and methods section (line 80-82) the explanation about the weighing of the garnishes, bread and deserts. The garnishes, bread and desserts were weighed daily 10 units of each and the average value obtained for each of them was used for nutritional assessment.

Results

- Line 127, if the weighing included both first and second courses, why is there only 79 first and 82 second courses. It is still not clear how then the other menu items such as garnish, dessert, bread and beverages were assessed and included in the results.

There are only 79 first and 82 second courses, because these were the total number of different dishes offered during the study period.

- Figure 1 Is cut off and not showing probably- This figure is to show the main ingredient yet one of the options is ‘precooked’ 5%.

As we have answered above, meat/fish or eggs groups have a clearly identifiable majority component, while the precooked ones respond to processed products and the "other" group are dishes in which there is no clearly majority ingredient (meat/fish crepes, contain in addition to these ingredients the sauce, dough, vegetables, etc.).

- Table 1 indicates the average energy contributions, but garnishes, dessert, bread, beverages and desserts were not weighed as part of the analysis. The methods section needs to describe in more detail how these were assessed to establish serve size and ingredient content.

Thank you very much about this comment, we have added it in line 80-82.

- Line 171 Indicates the first and second courses were in the appropriate caloric range for the midday meal. While EFSA is mentioned in the methods, the analysis methods indicates calculating quartiles not benchmarking against a caloric range for a midday meal. The kcal levels presented on Line 175 would appear to be for a whole day? Can the methods be clearer on how the total kcal were calculated and benchmarked. For example, in Table 1 the Men % and Women % is of their recommended daily kcal?

As you comment, the values presented on line 175 are for a whole day, and the same with table 1, men or women %. The total Kcal were calculated adding the average caloric contributions of the rest of the components of the menu to the caloric intake from the main components of the menu (first and second courses) (line 164-166).

- The remaining nutrient analysis from Line 182 seem only for the first and second courses as these were the only parts of the lunch service weighed? Same with Table 3 and 4? Therefore, the majority of the results are not from the entire menu but just the first and second course combinations?

Yes, the results about macro and micronutrients were only from de main components of the menu, first and second course. We have added this information in the manuscript (lines 172 and 182).

3.2 Environmental impact assessment

- Line 250-252 is part of the introduction- the results should just state the findings. The Introduction does not mention the 2020-2030 Agenda and Sustainable Development Goals. Can the authors describe what is specifically in these documents that indicates which foods are more sustainable than others?

As you comment us, the sentence in line 256-257 about 2020-2030 Agenda and Sustainable Development Goals has been deleted, because it was not suitable as part of the results.

Author Response File: Author Response.docx