Ethical, Stigma, and Policy Implications of Food Addiction: A Scoping Review

Round  1

Reviewer 1 Report

Review strengths include the clear writing style, logical order of presentation, and topic of high interest in the media and in the research community. The addition of stakeholder input (stakeholder summit) further strengthens this review.

Introduction.

-          The paragraph that begins with line 64 and mentions the “diagnostic challenges of food addiction” may benefit from 1-2 additional sentences clarifying this statement (withdrawal, tolerance, etc.)

Methodology.

-          While the authors acknowledge that they did not rate the “quality” of the studies/study designs in the Discussion, were any guidelines used in regards to sample size, design or duration when selecting appropriate studies (beyond English language and human)?

-          Can the authors provide more information on the coding process mentioned?

Discussion.

-          Beside Big Tobacco, were any comparisons to FA policy found as applied to recent policy efforts regarding sugar-sweetened beverages (Philadelphia, NYC, Seattle?).

Author Response

March 8, 2019

Attention:         Reviewer 1   

 RE:  Ethical, Stigma, and Policy Implications of Food Addiction: A Scoping Review

 Dear Reviewer 1,

 We are pleased to resubmit the revision of our manuscript previously entitled, “Ethical, Stigma, and Policy Implications of Food Addiction: A Scoping Review”. We greatly appreciate the time taken by you to provide valuable comments. The revisions to your feedback have been summarized below.

Introduction: The paragraph that begins with line 64 and mentions the “diagnostic challenges of food addiction” may benefit from 1-2 additional sentences clarifying this statement (withdrawal, tolerance, etc.).

 Response to Introduction: We appreciate the reviewer’s comments related to our introduction. We have included additional wording to clarify the diagnostic challenges of food addiction to further emphasize the previously outlined diagnostic challenges summarized later in the same paragraph.

Revisions: Introduction – page 2, lines 77-78

 Methodology, Point 1: While the authors acknowledge that they did not rate the “quality” of the studies/study designs in the Discussion, were any guidelines used in regards to sample size, design or duration when selecting appropriate studies (beyond English language and human)?

 Response to Methodology, Point 1: We thank the reviewer for this feedback. Systematic reviews often use quantitative or statistical techniques that look at the strength of evidence. Scoping reviews may be considered a type of systematic review, but the analysis is qualitative rather than quantitative. While a scoping review may be systematically conducted, the purpose of a scoping review is to synthesize qualitatively the literature on a particular topic or question. Moreover, issues related to ethics, stigma and policy in food addiction may be captured in publications that are not formal trials (e.g., commentaries). For these reasons, we did not have any limitations in regards to sample size, design, or duration in order to be more inclusive and capture these publications in the literature.

 Methodology, Point 2: Can the authors provide more information on the coding process mentioned?

 Response to Methodology, Point 2: The coding process involved looking at meaningful units and generating codes which were then reviewed and summarized in an iterative process to generate higher order themes. We have elaborated on these methods in the paper.

Revisions: Materials and Methods, Stage 5 – page 6, lines 214-217

 Discussion: Besides Big Tobacco, were any comparisons to FA policy found as applied to recent policy efforts regarding sugar-sweetened beverages (Philadelphia, NYC, Seattle)?

 Response to Discussion: We thank the reviewer for this comment. We do not specifically make comparisons to policy efforts outlined by Philadelphia, NYC, or Seattle but we do make reference to reducing access to addictive foods like sugar in Section 3.3.2.

 All authors are responsible for all contents of the article, and had authority over manuscript preparation and the decision to submit the manuscript for publication. All listed authors have approved of the re-submission of the manuscript to the journal.

 Thank you for reconsidering our manuscript for publication in your journal. We look forward to your response.

Author Response File: Author Response.docx

Reviewer 2 Report

Although it potentially becomes a bit clearer on reading further, it is not clear why point 3 (link between obesity or binge eating and addiction or substance use) was an inclusion criteria. It would be good if the authors can include a justification for this. 

Line 129 - A literature search with the date range until January 26th, 2017 - do you mean all literature until this date?

There are sections on food taxation and limited marketing of addictive foods as well as mention of calorie dense foods but it is not clear what there foods are. The authors do mention the current inability to classify foods as addictive. This remains a big limitation as no strategies can be adopted around food addiction if what addictive foods are is unknown. Additionally, food addiction is harder to identify than other forms of addiction (tobacco, substance use, etc) and thus further complicates the picture.

Some of the themes are directly linked to obesity. Although a link has been suggested between food addiction and obesity, food addiction is likely to be one factor contributing to obesity and individuals can presumably be addicted to food without being obese. Some of the messages seem more associated with obesity rather than food addiction.

Author Response

March 8, 2019

 Attention:         Reviewer 2   

 RE:  Ethical, Stigma, and Policy Implications of Food Addiction: A Scoping Review

 Dear Reviewer 2,

 We are pleased to resubmit the revision of our manuscript previously entitled, “Ethical, Stigma, and Policy Implications of Food Addiction: A Scoping Review”. We greatly appreciate the time taken by you to provide valuable comments. The revisions to your feedback have been summarized below.

 Point 1: Although it potentially becomes a bit clearer on reading further, it is not clear why point 3 (link between obesity or binge eating and addiction or substance use) was an inclusion criteria. It would be good if the authors can include a justification for this.

 Response to Point 1: We thank the reviewer for this feedback. Our grant and research question were focused on studying the link between the domains of food addiction and obesity. Additionally, the terms “substance use” and “addiction” were used as the term “food addiction” was defined much later on in the literature and we wanted to ensure that we captured all relevant articles published prior to the emergence of the term “food addiction”.

Revisions: Materials and Methods, Stage 1 – page 3, line 123

 Point 2: Line 129 – A literature search with the date range until January 26^th, 2017 – do you mean all literature until this date?

 Response to Point 2: Thank you for this comment. We meant to include all literature until this date. We have revised the wording at the beginning of Stage 2 in the Materials and Methods section to make this clearer.

Revisions: Materials and Methods, Stage 2 – page 4, line 143

 Point 3: There are sections on food taxation and limited marketing of addictive foods as well as mention of calorie dense foods but it is not clear what these foods are. The authors do mention the current inability to classify foods as addictive. This remains a big limitation as no strategies can be adopted around food addiction if what addictive foods are is unknown. Additionally, food addiction is harder to identify than other forms of addiction (tobacco, substance use, etc.) and thus further complicates the picture.

 Response to Point 3: We thank the reviewer for this comment and completely agree with the challenges. This is the basis of our current scoping review and we appreciate that it underscores the need for this publication. These issues are highlighted in sections 3.3.2 and 4.3 of the scoping review.

 Point 4: Some of the themes are directly linked to obesity. Although a link has been suggested between food addiction and obesity, food addiction is likely to be one factor contributing to obesity and individuals can presumably be addicted to food without being obese. Some of the messages seem more associated with obesity rather than food addiction.

 Response to Point 4: As mentioned in the response to point 1 above, the link between food addiction and obesity is related to our research grant’s original research question. To further clarify, we have added the word “obesity” into our research question description to be clearer about this focus. In addition, most literature related to stigma and policy focus on the impact on weight management in the context of obesity, which further reinforces our purpose and goal of this scoping review.

Revisions: Materials and Methods, Stage 1 – page 3, line 125

 All authors are responsible for all contents of the article, and had authority over manuscript preparation and the decision to submit the manuscript for publication. All listed authors have approved of the re-submission of the manuscript to the journal.

 Thank you for reconsidering our manuscript for publication in your journal. We look forward to your response.

Author Response File: Author Response.docx

Reviewer 3 Report

Review Nutrients 449273: “Ethical, Stigma, and Policy Implications of Food

 Addiction: A Scoping Review”

 I agree with the authors on the lack of research examining ethical, stigma and health policy implications of food addiction. Thus, a systematic review on this topic is welcomed and can address the gaps in the literature. Although the topic of the study is interesting and can expand our understanding on the food addiction, there are some weaknesses which can limit the impact of the study’s findings.

In my view, the systematic reviews on qualitative data are tricky. Moreover, as the authors affirmed, there is no assessment of the quality of evidence of the eligible studies. 

Another shortcoming is that the data from the eligible studies are reported in a very vague way (for example in Table 1). 

 General comments are outlined below:

 The intro is well written and describe the main characteristics of food addiction as well as the ongoing debate about its validity, especially on the differences between food addiction, obesity and binge eating disorder. Maybe it could be shortened a bit and elaborated on. For example, more direct building of a rationale that integrates the constructs of food addiction, obesity, and their negative consequences, etc. would help the reader understand how the pieces fit together, what the gaps are (and I would lead with the clinical significance of those gaps), and how this study addresses those key gaps.

 The different stages which were followed for conducting the scoping review are reported.

 Lines 108-109. Please expand a bit on the characteristics of the pre-summit online questionnaire on ethical and policy issues.

 Lines 128-139

Please specify the date range for the search: from….to January, 2017. The authors could also include the list of the search terms which were used for identifying the relevant studies (maybe as a supplementary table).

 Lines 150-153. The authors should explain in more detail how the reviewers have identified relevant themes and quotes in the screened full texts. Please be also more specific on the process of coding of these qualitative data. At line 155, the authors affirm that 3 main themes were identified. I suppose they are referring to ethics, stigma and policy implications. Please provide this information more clearly.

 Please add the reasons for exclusion in the flow-chart.

 Line 313. The authors say that 31 articles were selected for the policy themes. However, in the Appendix A just 30 papers are reported. Please be consistent with that.

  In the Discussion, I encourage authors to write more about the implications for treatment of food addiction and expand overall on their argument about characterizing food addiction as a behavioral addiction, as it could be relevant for readers.

Author Response

March 8, 2019

 Attention:         Reviewer 3   

 RE:  Ethical, Stigma, and Policy Implications of Food Addiction: A Scoping Review

 Dear Reviewer 3,

 We are pleased to resubmit the revision of our manuscript previously entitled, “Ethical, Stigma, and Policy Implications of Food Addiction: A Scoping Review”. We greatly appreciate the time taken by you to provide valuable comments. The revisions to your feedback have been summarized below.

 Point 1: In my view, the systematic reviews on qualitative data are tricky. Moreover, as the authors affirmed, there is no assessment of the quality of evidence of the eligible studies. Another shortcoming is that the data from the eligible studies are reported in a very vague way (for example in Table 1).

 Response to Point 1: We thank the reviewer for this feedback. We agree that this is not a systematic review and adhered to evidence-based methods for scoping reviews, which are widely published in the literature. As mentioned in our response to Reviewer 1, systematic reviews often use quantitative or statistical techniques that look at the strength of evidence. Scoping reviews may be considered a type of systematic review, but the analysis is different in that while a scoping review may be systematically conducted, its purpose is different than a systematic review. Extracted from Arksey and O’Malley’s 2005 paper entitled, “Scoping Studies: Towards a Methodological Framework”:

 “… the scoping study might be conceived as a method in its own right – leading to the publication and dissemination of research findings in a particular field of enquiry. The aim of identifying gaps in the existing evidence base is clearly important, and may or may not lead ultimately to a full systematic review.” – pp. 7

 “The method adopted for identifying literature in a scoping study needs to achieve in-depth and broad results. Rather than being guided by a highly focussed research question that lends itself to searching for particular study designs (as might be the case in a systematic review), the scoping study method is guided by a requirement to identify all relevant literature regardless of study design. … The process is not lintear but iterative …” – pp. 8

 Our coding process involved looking at meaningful units and generating codes which were then reviewed and summarized in an iterative process to higher order themes. We used rigorous qualitative methodology to ensure we analysed text from these publications to identify themes from publications. Table 1 is a summary of representative quotes under each theme to provide an example of text related to each theme (similar to the presentation of sample data in other qualitative study results). To provide more detailed information, we have revised the Results section to include the number of reviews, original research articles, editorials, commentaries, opinions, and briefs that were included in the analysis. We trust that this has addressed this issue.

Revisions: Results – page 6, lines 223-224

 Point 2: More direct building of a rationale that integrates the constructs of food addiction, obesity, and their negative consequences etc. would help the reader understand how the pieces fit together, what the gaps are (and I would lead with the clinical significance of those gaps), and how this study addresses those key gaps.

 Response to Point 2: We thank the reviewer for this comment. We have addressed this by including an additional paragraph with more information on the potential negative outcomes of food addiction and obesity.

Revisions: Introduction – page 2, lines 54-59

 Point 3: Lines 108-109. Please expand a bit on the characteristics of the pre-summit online questionnaire on ethical and policy issues.

 Response to Point 3: The pre-summit online questionnaire was derived from studies referenced in the review (references #36 and #37) and also had open-ended questions regarding the potential implications of food addiction on stigma, ethics, and health policy. We have included this in the text.

Revisions: Materials and Methods – page 3, lines 118-120

 Point 4: Lines 128-139. Please specify the date range for the search: from … to January, 2017.

 Response to Point 4: We have revised the wording at the beginning of Stage 2 in the Materials and Methods section to make this clearer.

Revisions: Materials and Methods, Stage 5 – page 6, lines 212-215

 Point 5: Lines 150-153. The authors should explain in more detail how the reviewers have identified relevant themes and quotes in the screened full texts. Please also be more specific on the process of coding of these qualitative data. At line 155, the authors affirm that 3 main themes were identified. I suppose they are referring to ethics, stigma and policy implications. Please provide this information more clearly.

 Response to Point 5: Please refer back to the above Response to Point 1. As per the reviewer’s suggestion, we have also indicated more clearly in the Materials and Methods the 3 main domains identified.

Revisions: Materials and Methods, Stage 5 – page 6, lines 212-215

 Point 6: Please add the reasons for exclusions in the flow-chart.

 Response to Point 6: Articles eliminated at point of full screening were deemed not directly relevant to the topic (i.e., the articles were more relevant to obesity or binge eating without a clear link to food addiction).

Revisions: Figure 1 – page 5

 Point 7: Line 313. The authors say that 31 articles were selected for the policy themes. However, in the Appendix A just 30 papers are reports. Please be consistent with that.

 Response to Point 6: We thank the reviewer for pointing this out this discrepancy. The missing article has been added to Appendix A.

Revisions: Appendix A – page 21, lines 728-730

 Point 8: In the Discussion, I encourage authors to write more about the implications for treatment of food addiction and expand overall on their argument about characterizing food addiction as behavioural addiction, as it could be relevant for readers.

 Response to Point 6: We thank the reviewer for this feedback. As indicated in our manuscript, the treatment of food addiction is beyond the scope of this particular scoping review. There is no published research to date that has empirically examined the impact of psychosocial interventions for food addiction. We have made mention to the fact that characterizing food addiction as a behavioural addiction would likely have an adverse impact on externalized stigma and further expand this point in lines 556-566.

 All authors are responsible for all contents of the article, and had authority over manuscript preparation and the decision to submit the manuscript for publication. All listed authors have approved of the re-submission of the manuscript to the journal.

 Thank you for reconsidering our manuscript for publication in your journal. We look forward to your response.

Author Response File: Author Response.docx

Round  2

Reviewer 3 Report

I have carefully reviewed the revised manuscript. I felt that this version was successful in addressing the concerns raised at earlier stages of the review process.