Relationship of Physical Activity and Sleep Duration with Self-Concept, Mediterranean Diet and Problematic Videogame Use in Children: Structural Equation Analysis as a Function of Gender

Round 1

Reviewer 1 Report

Line 53: Provide references for choosing the elements listed in the sentence.

Line 72: Reword control-skills objects to object control skills.

Line 78: The sentence seems to be missing some wording (girls?) as it is not clear what is being said.

Line 88: It should be noted that other healthy eating approaches also algin with other healthy habits. To only state the Mediterranean diet would be misleading.

Line 94: Replace less with lower.

Line 95-96: Need better sentence flow from video games to the elements of self-concept affected.

Line 103: Potential and severe problems in regard to what?

Line 105: Should be gaming not gambling.

Lines 417-418; 452-453: In the tables provided, for females there was no significant relationship between SC and MD. Please explain from the data the conclusions being derived.  

Results Section

Provide more descriptive data (tables) in the results section to give a better baseline of the population within the study.

Overall Thoughts

This is a good study that brings valuable information to the field and public. The manuscript itself was solid and only needs minor editing.

Author Response

Dear Reviewer, 

 

I am attaching the required changes.

 

Thank you!

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

 

1. In the abstract, authors write: "In boys, there was a direct effect of self-concept with sleep duration and adherence to the Mediterranean diet" -- do authors mean direct effect ON sleep duration and adherence to the Mediterranean diet?

 

2. In the abstract (lines 31-32), the authors write about the positive relationship of physical activity with problematic video games for girls. However, the discussion indicates an inverse relationship between the two (I suppose for girls and boys) (lines 406-407).

 

3. There are so many confounders and omitted variables when it comes to the model and the variables included in the study. Moreover, I am not sure how the authors developed this elaborate hypothesis/model without including important variables such as parental engagement, sibling count, household size, parental education and job, height, weight, BMI, grades, access to healthcare, access to facilities, urban vs. rural, and many other variables that may further (and in some cases better) explain why 11-12-year-olds do what they do? I understand that it is impossible to have all the necessary covariates, and researchers will never get to the truth. For such cases, then, it is essential to have competing models. Specifically, the value of the study would be in comparing the competing models to get closer to the truth and select a model with the best statistical and conceptual fit.

 

4. Moreover, the coefficients might be statistically significant with the given sample size, but are they practically significant? In other words, the effect sizes need to be obtained and interpreted.

 

5. Mediterranean diet: what makes it different/unique? Do you mean a healthy diet? These are 11-12-year-olds -- I am not sure if they can explain what the Mediterranean diet is?

 

6. Figure 1: authors' use of circular and rectangular figures (perhaps to indicate the nature of the variable, i.e., latent variable vs. manifest variable?) is confusing (not conventional) and needs to be clarified.

 

7. I am not convinced about the directionality of the arrows in the theoretical model (Figure 1). I would be more convinced if there were more bidirectional arrows (implying correlation and not causation). I can come up with many counterexamples to argue the reversal of these arrows. Arrows indicate "cause," and while I understand that authors may be using it loosely and realize that getting from correlation to causation is almost impossible, the model in Figure 1 does not reflect that.

Author Response

Dear Reviewer, 

 

I am attaching the required changes.

 

Thank you!

 

 

Author Response File: Author Response.docx

Reviewer 3 Report

Take care with the authors. You can get off them in the text.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer, 

 

I am attaching the required changes.

 

Thank you!

 

 

Author Response File: Author Response.docx