Review for 10.1186/s12876-020-01204-3 (2020)

Reviewer ’s report  
 
Title: Physical activity intervention for non -diabetic patients  with non -alcoholic fatty liver 
disease: a meta -analysis of randomized controlled trials  
 
Version: 0 Date: 21 Dec 2019  
 
Reviewer: Valerio Rosato  
 
Reviewer's report:  
The authors of the research article submitted by Shu -ting Wang et al have done an impressive 
work performing a meta -analysis on eleven studies on the effectiveness of physical activity 
intervention as a treatment of NAFLD.  
The authors, from the analysis of the results obtained, concluded defining that physical activity 
alone can only slightly improve liver injury, lipid and glucose metabolism.  
The work seems to have been well done, but th e authors leave to the readers a message that 
contrasts with the current guidelines on NAFLD treatment. In fact, the life -style correction is 
mandatory in all patients with NAFLD.  
 
The work has potential to gain interest to the readers and increases the ev idences actually 
available on this topic, but some revisions are needs to make the manuscript suitable for the 
publication.  
 
Major revisions:  
In table 1, 29 patients were included in the study of Shojaee et al 2016. In this study were 
enrolled 27 patients.  It's a typo? In this case, the authors should correct the table, the total 
number of involving participants and all others related sections.  
The authors should make the same assessments for the study of Jia et al 2018. In table 1 was 
included 461 patients , but 474 patients were enrolled in this study. It is another typo? The 
authors should provide any clarifications about this discrepancy.  
 
 
 
The authors should add to the discussion, between the limitations of the study (page 15, line 30 -
33), a statement con cerning the lack of histological improvement evaluations in the analyzed 
RCTs, giving some references and an accurate description of the available literature on this topic 
(e.g. DOI: 10.1053/j.gastro.2015.04.005; DOI: 10.1002/hep.23276;…). Consequently, in  the 
light of the correction to discussion, the authors should rewrite the conclusions of the study.  
 
Furthermore, some minor revisions are needs in the background section.  
Please see below for the specific comments:  
Page 4  
line 14. The reference 3 provides a wide information about the epidemiology of NAFLD on the 
American and Asian continents, but not good information about the epidemiology of European 
continent. Authors are highly recommended to use following citation (DOI:  
10.2174/1574887109666141216111143) for this statement, in order to give a complete and 
satisfactory definition of the global NAFLD scenario.  
 
Line 20.  It is highly recommended for authors to rephrase the following sentence:" … which 
includes increasing p hysical activity and diet alteration "  
 
Line 36. It is suggested that the authors provide a reference for this statement.  
 
 
Are the methods appropriate and well desc ribed?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
No 
 
Are you able to assess any statistics in the manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please speci fy what aspects require further 
assessment in your comments to the editors.  
 
I recommend addit ional statistical review  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, f ees, funding, or salary from an 
organisation that may in any way gain or lose financial ly from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation t hat may in any way gain or lose 
financially from the publication of this manuscript, either now or in the futu re? 
 
3. Do you hold or are you currently applying for any patents  relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have  no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
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on my report to the authors and, if the manuscript is accepted f or publication, my named report 
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