The daytime feeding frequency affects appetite-regulating hormones, amino acids, physical activity, and respiratory quotient, but not energy expenditure, in adult cats fed regimens for 21 days

Alexandra Camara; Adronie Verbrugghe; Cara Cargo-Froom; Kylie Hogan; Trevor J. DeVries; Andrea Sanchez; Lindsay E. Robinson; Anna K. Shoveller

doi:10.1371/journal.pone.0238522

Peer Review History

Original SubmissionMay 25, 2020
17 Jul 2020 Decision Letter - Juan J Loor, Editor PONE-D-20-15734 The daytime feeding frequency affects appetite-regulating hormones, amino acids, physical activity, and respiratory quotient, but not energy expenditure, in adult cats fed regimens for 21 days PLOS ONE Dear Dr. Shoveller, 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 submit your revised manuscript by Aug 31 2020 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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(Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: PONE-D-20-15734 The daytime feeding frequency affects appetite-regulating hormones, amino acids, physical activity, and respiratory quotient, but not energy expenditure, in adult cats fed regimens for 21 days I found the paper to be ab excellent contribution to the area. It was thorough and encompassing. My concerns were a lack of understanding of the experimental design and an apparent liberal application of statistics. However, the data are excellent despite a rather limited number of experimental observations. Line 57 Delete been 60 Delete should 134 Change “recorded in grams (orts)”. To ‘orts recorded’ 150 ‘2 x 3 replicated incomplete Latin square design’ I can say with complete confidence that this is one I have never heard of. I have read this multiple times and just cannot grasp all that was done. You describe an experiment that has periods and then you describe study 1 and study 2. What is a study? What in this relates to 2x3? I suspect it is not as Latin square bur is a crossover design. 188 You should name the actual additives. 190 Delete and to 278 I did not understand much about the design, I know you cannot have 8 cats and an n=12. Just not possible. 293 You should probably point out that there were Time x Trt effects that make these comparisons relevant as opposed to Trt effects which are not. 535 I do not see anything that gives relevance to this carbohydrate ceiling discussion. I would delete it. 560 A lot of discussion for RQ of 0.68 vs 0.70. Is this really significant or perhaps driven by the intake differences? Point is the discussion could be shortened some and this might be an opportunity. ****** 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 [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. 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Revision 1
13 Aug 2020 Author Response Reviewer #1: PONE-D-20-15734 The daytime feeding frequency affects appetite-regulating hormones, amino acids, physical activity, and respiratory quotient, but not energy expenditure, in adult cats fed regimens for 21 days I found the paper to be ab excellent contribution to the area. It was thorough and encompassing. My concerns were a lack of understanding of the experimental design and an apparent liberal application of statistics. However, the data are excellent despite a rather limited number of experimental observations. Response: Thank you for your kind words. We too are excited about this data. Thank you for your patience while we found time to revise our manuscript. Line 57 Delete been Response: Completed. 60 Delete should Response: Completed. 134 Change “recorded in grams (orts)”. To ‘orts recorded’ Response: Completed. 150 ‘2 x 3 replicated incomplete Latin square design’ I can say with complete confidence that this is one I have never heard of. I have read this multiple times and just cannot grasp all that was done. You describe an experiment that has periods and then you describe study 1 and study 2. What is a study? What in this relates to 2x3? I suspect it is not as Latin square bur is a crossover design. Response: Latin square designs are commonly used in animal science and agricultural research and each treatment is equally represented in each period. Latin square designs are similar to cross-over designs, but ensure that treatments are equally allocated within period and blocking criteria (sex) is equally represented within treatments. We have added the following explanation in the text in the Experimental Design section: “Meal frequency was tested in two separate studies, each using a 2 x 3 replicated incomplete Latin square design with two treatments (one vs. four times feeding frequency) and three periods. The third period allowed us to account for carry over effects of feeding frequency in such that we sought to understand whether a longer time receiving a feeding frequency altered our physiological response criteria. Because all cats repeated one of two treatments, this resulted in 12 experimental periods per treatment as four out of eight cats repeated one of two treatments.” 188 You should name the actual additives. Response: We have added the full name, Dipeptidyl peptidase-IV inhibitor. 190 Delete and to Response: Deleted. 278 I did not understand much about the design, I know you cannot have 8 cats and an n=12. Just not possible. Response: We included the repeated period that 50% of the cats did on each treatment, resulting in an n=12. To make this more clear we have added Number of subjects (n=8) and experimental periods (11 or 12 depending on outcome) to the tables and figures. 293 You should probably point out that there were Time x Trt effects that make these comparisons relevant as opposed to Trt effects which are not. Response: Great point, thank you. 535 I do not see anything that gives relevance to this carbohydrate ceiling discussion. I would delete it. Response: We had included this as the rationale for the lower voluntary food intake noted in cats fed once a day, but agree that it likely does not add much to the discussion and have deleted that paragraph. 560 A lot of discussion for RQ of 0.68 vs 0.70. Is this really significant or perhaps driven by the intake differences? Point is the discussion could be shortened some and this might be an opportunity. Response: Indirect calorimetry is very precise and changes in macronutrient partitioning underpin respiratory quotients. Because the current results suggest an increase in lipid utilization for energy production and are clinically relevant to weight loss strategies, as such, we would prefer to leave this discussion in. https://doi.org/10.1371/journal.pone.0238522.r002
19 Aug 2020 Decision Letter - Juan J Loor, Editor The daytime feeding frequency affects appetite-regulating hormones, amino acids, physical activity, and respiratory quotient, but not energy expenditure, in adult cats fed regimens for 21 days PONE-D-20-15734R1 Dear Dr. Shoveller, 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. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. 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, Juan J Loor Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0238522.r003
Formally Accepted
1 Sep 2020 Acceptance Letter - Juan J Loor, Editor PONE-D-20-15734R1 The daytime feeding frequency affects appetite-regulating hormones, amino acids, physical activity, and respiratory quotient, but not energy expenditure, in adult cats fed regimens for 21 days Dear Dr. Shoveller: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. 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. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Juan J Loor Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0238522.r004

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