Differences in Environmental Impact between Plant-Based Alternatives to Dairy and Dairy Products: A Systematic Literature Review

Round 1

Reviewer 1 Report

In my opinion, the article is written correctly, in accordance with the standards set for scientific studies. The manuscript deals with a current topic that is sure to be on top for the next few years. After reading the text several times, no errors were found, so I recommend it for further editorial stages in the current version. 

Author Response

Thanks for your your encouraging evaluation.

Yours truly

Annika Carlsson Kanyama

Reviewer 2 Report

Excellent work. Research is well designed and conclusions are sound and of pratical interest. I have some minor suggestions for revision in the attached document. Citations in text must be revised and list of references carefully checked.

Comments for author File: Comments.pdf

Author Response

Thanks for all your useful suggestions. Everything  has been fixed. The revised manuscript is attached.

Yours truly

Annika Carlsson Kanyama

Author Response File: Author Response.docx

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

Before the authors start questioning our review and decision regarding this manuscript, I would like to make an analogy that I believe will clearly explain what is my major concern regarding this article:

1a. An internal combustion engine (ICE) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. Vehicles that use ICE are called ICE vehicles.

2a. An electric motor (EM) is an electrical machine that converts electrical energy into mechanical energy. Vehicles that use EM are called electric vehicles (EV’s)

3a. There is no “electric motor-based ICE vehicles” because such a thing does not exist. The vehicle is either ICEV’s or EV’s.

The analogy is:

1. Dairy products or milk products are a type of food produced from or containing the milk of mammals, most commonly cattle, water buffaloes, goats, sheep, and camels.
2. There is no milk-based dairy product because all dairy products contain milk.
3. There is no plant based dairy product. Instead, you can only make plant based dairy product alternative or analogue.

Unfortunately, the authors are using those (wrong) terms across the manuscript, including the title. Therefore, we must advise the authors to provide definitions of all the terms they are going to use, having in mind that “plastic based wooden table” does not exist.

Reviewer 2 Report

The manuscript "Differences in environmental impact between plant- and milk-based dairy products: A systematic literature review", as indicated in the title, reports the results of a systematic literature review aimed at comparing the environmental performance of plant-based (PB) and milk products. While I believe the work is relevant, the major points outlined below have to be addressed before the manuscript is ready for publication.

GENERAL COMMENTS:

• The literature review included in the introduction section is incomplete. For example, in L43, the authors suggest that PB diets are generally healthier but failed to include key pieces of literature such as White and Hall (2017), who discuss the implications of PB diets from a nutritional perspective;
• The reference for the systematic literature review guideline (PRISMA; Liberati et al., 2009) seems to be outdate based on a recent publication by Page et al. (2020);
• the description of the methodology is ambiguous. For example, it's not clear if all studies are full or partial life cycle assessments. Also, the methods don't describe if any product co-allocation of environmental footprints were included in the studies cited. These aspects can have implications to the results. Finally, the description of the weighing method is not clear and doesn't allow the reader to assess if it's adequate or not;
• the results section is just a summary of quantitative results of the manuscripts selected for review, without providing much context about the studies. The authors state that for some categories, there were only a few studies selected (in some cases, a single study). In this case, better context and description about those few studies are needed to avoid bias coming from a single source. The table numbering is also inconsistent;
• the discussion section needs much improvement. First, the fails to discuss important aspects such as biodiversity. In L391, the authors state that no studies were found regarding biodiversity, but this doesn't prevent them from discussing this issue. However, in L411, the authors make a seemingly arbitrary decision to discuss studies that "deserve to be mentioned". This creates some issues about biases in the way the study was conducted. 

SPECIFIC COMMENTS

Specific comments were included in the annotated PDF file.

Comments for author File: Comments.pdf

Reviewer 3 Report

Dear Authors,

The manuscript is of an overview character. It is well organized and well written. In order to improve the manuscript, I propose:
1. Improve the discussion.
2. Describe the limitations.
3. Describe future research.