Review for 10.1186/s12876-023-02785-5 (2023)

Title: Fatty liver index relationship with bio markers and lifestyle: Result from RaNCD cohort
study
Version: 1 Date: 13 Jan 2023
Reviewer's report:
Thanks for the opportunity to review this interesting manuscript titled “Fatty liver index
relationship with bio markers and lifestyle: Result from RaNCD cohort study”. The following
manuscript aims to investigate the effects of lifestyle risk factors on fatty liver index in Iranian
adults. Please review the following comments as I hope including further details will increase
the nuance of the manuscript.
Major comments:
1. ABSTRACT: Please, review the introduction as well as the concordance between the results
and conclusions presented.
2. It is recommended that the authors add the term MAFLD, a consensus-driven proposed
nomenclature for NAFLD.
3. Statistical analysis: For continuous non-parametric variables, data should preferably be
expressed as median (IQR).  Please specify this in the statistical analysis section.
4. Statistical analysis: Have variables been tested for normality? In the case of non-parametric
variables, which test has been used to obtain the p-value?
5. Results: It would be helpful if the authors could add in Table 1 how many of the participants
had diabetes. Diabetes should also be considered as an adjustment variable in the regression
model (Table 3).
6. Results: Some of the results discussed by the authors are described in a very general way. For
example, almost nothing is said about the results related to depression, whereas in the conclusion
they are emphasised.
7. Results: Regression model (Table 3), please check the following:
- One of the variables used to predict FLI is BMI. However, the formula for calculating FLI
already includes BMI, so it would be an over-fitted model.
- Could the authors redesign the table so that the p-values are indicated in both regression
models?
- Has the potential increased risk of FLI according to HEI been analysed?
8. Discussion: “Our findings showed that factors like low SES, inactivity, depression, and less
adherence to HEI 2015 all related to the increased risk of NAFLD”. The authors claim this, but
results in the regression model shows the following:
- A positive association between Good socio-status and FLI#60 in both men and women
(unadjusted OR: 1.72 and OR: 1.25 respectively).
- In relation to depression and the risk of FLI#60 the model shows a negative relationship in men
(OR unadjusted: 0.89), while only in women does it appear to be positive (OR unadjusted: 1.68).
Please review the results and the discussion of these results.
9. Please indicate the studies where the issue has been studied. Discussion “Previous studies
done on adults revealed that the frequency of NAFLD was linked to increased sitting duration
and lower PA levels”.
10. As well as the lack of data related to MRI, a major limitation is the lack of liver biopsy
data, which is the gold standard for NAFLD diagnosis. Please add this to the limitations of the
manuscript.
11. The conclusions of the article seem too general and some of them do not relate to the results
presented.
12. The work must be proofread by a native English speaker.