PONE-D-20-39574

Dietary adherence and program attrition during a severely energy-restricted diet among people with class III obesity: a qualitative exploration

PLOS ONE

Dear Dr. Maston,

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 address the reviewer comments.

Please submit your revised manuscript by Apr 15 2021 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.

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We look forward to receiving your revised manuscript.

Kind regards,

Shahrad Taheri

Academic Editor

PLOS ONE

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5. Thank you for stating the following in the Competing Interests section:

"AS is the author of The Don’t Go Hungry Diet (Bantam, Australia and New Zealand, 2007) and Don’t Go Hungry For Life (Bantam, Australia and New Zealand, 2011). She has also received payment from Eli Lilly, the Pharmacy Guild of Australia, Novo Nordisk, the Dietitians Association of Australia, Shoalhaven Family Medical Centres, the Pharmaceutical Society of Australia, and Metagenics, for presentation at conferences, and served on the Nestlé Health Science Optifast® VLCD™ Advisory Board from 2016-2018. TM has received payments from Novo Nordisk for seminar presentations at conferences. She has served on the Egg Nutrition Council for Australian Eggs since 2004 and Nestle Health Science VLCD Advisory Board since 2010. JF has received payments from Novo Nordisk, Illy, Boehringer Ingelheim and Nestle Health Science for seminar presentations. She served on the Nestle Health Science VLCD Advisory Board between 2009-2013. AAG has received payment from the Pharmacy Guild of Australia and from Nestlé Health Science for oral presentations at conferences. SH has received honoraria from Novo Nordisk, Inova, Sanofi, Eli Lilly, Boehringer Ingelheim and Astra Zeneca for seminar presentations. She has received research funding from Novo Nordisk. GM is the author of The Perfect Juice (New Holland, 2016) and received payment from Novo Nordisk for seminar presentations."

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: N/A

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: No

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Thank you very much for your recent submission titled “Dietary adherence and program attrition during a severely energy-restricted diet among people with class III obesity: a qualitative exploration”. This explored a very topical area of adherence to diets that severely restrict a person’s energy intake. Adherence to any dietary intervention is key to success therefore understanding key drivers is an important aspect that can help clinician better support their patients.

There are a couple of major points that I think would be good to address. The term “severely energy-restricted diets” is not a typical term that is used in the literature. Having read the manuscript it is clear that that are very clearly discussing a Very Low Energy Diets (VLED) By clearly defining this, the reader can see if the paper is relevant to them, therefore please can you consider changing the use of the term SERD to VLED or Formula Total Diet Replacement depending on which term you prefer. This will prevent the reader having to decipher the methodology before knowing if this is relevant to their practice.

Having read your paper, the patient group is more complex than the title suggests. This patient group is living with severe and complex obesity. Your mean BMI is 63.7kg/m2 at baseline. The biological drivers for individuals with BMI>50kg/m2 are more complex and this should be reflected within the title and manuscript as a novel aspect of this study. Furthermore, the EOSS score suggests that many have additional comorbidities as well.

Finally, there appears to be missing key literature from this paper that is directly relevant to the patient population and the dietary approach used:

Harper C, Maher J, Grunseit A, Seimon RV, Sainsbury A. Experiences of using very low energy diets for weight loss by people with overweight or obesity: a review of qualitative research. Obes Rev. 2018 Oct;19(10):1412-1423.

Astbury NM, Albury C, Nourse R, Jebb SA (2020) Participant experiences of a low-energy total diet replacement programme: A descriptive qualitative study. PLoS ONE 15(9): e0238645.

Christensen B, J, Iepsen E, W, Lundgren J, Holm L, Madsbad S, Holst J, J, Torekov S, S: Instrumentalization of Eating Improves Weight Loss Maintenance in Obesity. Obes Facts 2017;10:633-647.

Please can you consider including these references and how this manuscript adds to the evidence that is already published, this appears key to the framing of this manuscript.

PLease find below some additional points that would benefit from addressing:

Comments:

Line 53: the preferred term is weight-related stigma not obesity-related stigma

Line 62: The term “severely energy-restricted diets” is not a typical term that is used in the literature. Within your review in 2019 you use the terms VLED and LED which are known within the literature and would help the reader to grasp what the manuscript was about. At present I needed to search for what these diets were and read the entire methodology before understanding. Please can you give an energy definition to all the reader to understand.

Line 62: By meal replacements what do you mean? Are you talking about formula total diet replacements that replace the entire diet, partial TDR or meal replacements that replace 1-2 meals/day? This needs clarity as these different dietary approaches give different weight losses and differ in the way they are administered.

Line 77-78: Please consider including qualitative data from other authors here not just Rehackova et al., there is additional insight into the participants experiences which has been missed here. See above for details.

Line 105-119: As a clinician there remains a lack of clarity on what dietary approach you are using when you talk about the SERD, this is important to know what type of diet approach this data relates to. It appears from this description and the reference that you are using a total diet replacement VLED, this needs clarity – also what commercial product did you use.

Line 164-168: It would benefit to see the questions that were asked and how they were framed.

Line 177-183: It is unclear as to why you have used the EOSS tool, what is the relevance to the data being collected at present? As stated above this could be used to identify the complexity of the patient population your studied.

Line 288: Do you have any examples of stigmatising experiences that the participants experienced that made them hesitant

Line 357: There appears to be a feeling of personal failure within this quote was this reflected by others as this can often impact on adherence to dietary programmes with previously held beliefs on dietary success resulting in lack of confidence.

Line 384: Please have consistency with terms regarding stigma suggest using weight-related stigmatising experiences.

Line 387-399: These quotes appear to show feelings of fear related to their medical conditions driving adherence and motivating them to continue e.g. not being able to breathe, fear of death – was there a sense from others that this was an underlying driver?

Line 437: The element of simplicity of diet has been reflected in previous reviews of the topic for the benefit of formula VLED (Brown, A. and Leeds, A.R. (2019), Very low‐energy and low‐energy formula diets: Effects on weight loss, obesity co‐morbidities and type 2 diabetes remission – an update on the evidence for their use in clinical practice. Nutr Bull, 44: 7-24.) and also in qualitative research (Astbury et al., 2020, above). This should be acknowledged that this is already reported and your data supports this view.

Line 438-442: These quotes appear to identify that the use of formula product is the key to the dietary simplicity not just they are choosing from fewer foods.

Line 459-466: Was it the simplicity of the diet that allowed them to plan more easily and get a routine as before this was challenging with all the challenges that food selection requires.

Line 483-487: This infers that all participants had a positive experience from weigh-in and not achieving weight loss, was this universal or did some struggle with this and this impact on adherence to the program?

Line 553: Please change language to person first – ‘disabled participant’ should be ‘participants living with disability’

Line 575: Can you please confirm is this meal replacement product or formula VLED product they are purchasing or did this change as they progressed through the programme?

Line 610: Change terminology related to stigma as before – Also was there a sense of any internalised weight stigma impacted adherence e.g. “I’m lazy” “I’m unmotivated”.

Can I please ask how the question regarding stigma was framed as the quotes appear to suggest that the questions inferred people were feeling stigmatised or did this topic naturally come up in conversation.

Line 708: Is there a possibility that socio-economic factors developed due to the patient sample being mainly socio-economically disadvantaged and that this is simply reflective of your population rather than an issue. Did the issues of cost etc come out of people that were not consider socio-economically disadvantaged?

Line 723: This study offers unique perspective but to an even more unique population that has not been extensively researched before, this is people living with severe and complex obesity e.g. BMI>50kg/m2 and co-morbidities

Line 732: You mention weigh-related stigma being identified in screening do you have a suggestion on how this can be done? Questionnaire? Does this included internalised weight stigma which has been shown to impact healthcare outcomes and motivation to access healthcare. If so then this would benefit from being explore before the conclusion.

Reviewer #2: General Comment:

Overall the study addresses an important issue, which are the facilitators and barriers to patients undertaking severely energy-restricted diets to achieve weight loss.

Introduction:

1. The manuscript describes using severely energy-restricted diets (using meal replacement products) for weight loss. However the authors do not clearly define what is meant by severe energy restriction. Please clarify this.

2. The authors do not provide an adequate background on what is known in the literature about barriers and facilitators to the use of meal replacements (and other interventions using low energy diets) for weight loss and how knowledge gained from their study will add value.

Methods:

3. Much of the information under setting would be better suited as a description of the participants. Please review the subheadings under the methods section.

4. Why did the authors choose to study only participants with class III obesity? Were there any other inclusion/exclusion criteria? The authors described using “purposive sampling”, but did not elaborate on what kind of participants they aimed to include.

5. Duration of interviews and number of in-person/telephone interviews should be reported.

Results:

6. The table of participant characteristics can be organized in a way to help the reader gain a better understanding of the characteristics of participants. Consider arranging according to those who had achieved and maintained weight loss, those who did not achieve weight loss, and dropouts, or any other meaningful arrangement.

7. Please make sure figures in the table are consistently being rounded to the same decimal place.

8. It would be useful for the authors to provide a written summary of the weight loss outcomes achieved by the participants.

Discussion:

9. The authors report that 65% of participants were at socioeconomic disadvantage and this was one of the main barriers identified. How representative is this for the population being studied?

10. The authors do not discuss their findings in context of what is already known in the literature in enough depth.

11. The authors should consider what other limitations there are to the study.

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6. PLOS authors have the option to publish the peer review history of their article (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? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: Yes: Hadeel Zaghloul

[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.

PONE-D-20-39574R1

Dietary adherence and program attrition during a severely energy-restricted diet among people with complex class III obesity: a qualitative exploration

PLOS ONE

Dear Dr. Maston,

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 address the final reviewer comments.

==============================

Please submit your revised manuscript by Jun 11 2021 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.

Please include the following items when submitting your revised manuscript:

• 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 you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

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: http://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,

Shahrad Taheri

Academic Editor

PLOS ONE

Journal Requirements:

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.

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Thank you very much for your resubmission of this interesting manuscript on the topic of dietary adherence using severely energy-restricted diet. You have address the suggested comments previously highlighted. There are a couple of very minor addition points from the additional text added:

Line 152: please use the full company names i.e. Cambridge Weight Plan Ltd as the descriptor not Cambridge.

Line 176-180: With the greater explanation of the dietary methods this highlights a question regarding your primary outcome which was dietary adherence - Was there a difference in views between the group that had food and those that chose to just have the meal replacements only? Maybe suggest add a little clarity in the discussion.

Line 729: Your comment regarding “The interviews did not reveal internalized stigma as a factor in poor dietary adherence” is questionable. You did not measure internalised weight stigma using a questionnaire such as Weight bias internalisation scale and did not ask specific questions related to this, therefore how do you know? People living with obesity are often unaware of the internalisation of the weight stigma, as is internalisation of negative social stereotypes such as people with obesity are lazy, gluttonous etc. So it would unlikely come out in the interviews unless specifically addressed. This is more likely to be a limitation of the study and suggest removing this sentence and add to limitations.

Thank you

Reviewer #2: (No Response)

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7. PLOS authors have the option to publish the peer review history of their article (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? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: Yes: Hadeel Zaghloul

[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.

Dietary adherence and program attrition during a severely energy-restricted diet among people with complex class III obesity: a qualitative exploration

PONE-D-20-39574R2

Dear Dr. Maston,

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.

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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,

Shahrad Taheri

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: