Review Reports - Comparative Analysis of the Nutritional Composition of Gluten-Free and Gluten-Containing Bars Marketed to Children in Ontario

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Overall evaluation:
The rationale of this paper is very weak from a dietetic and nutritional standpoint, which is the main focus of Dietetics. The study might be more suitable for a journal related to marketing or food product development rather than a nutrition-focused publication.

The manuscript presents a comparative analysis of the nutritional composition of cereal bars marketed for children in Ontario, Canada. However, the authors’ justification for the study’s relevance is not convincing. They argue that such products might be relevant for gluten-free diets, but cereal bars are typically consumed only occasionally—certainly not as staple foods in a balanced diet. Given that these are snack foods, their recommended frequency of consumption should not exceed once per week, meaning that potential nutritional differences between gluten-free and gluten-containing bars have minimal dietary relevance. This limitation should have been clearly addressed. Moreover, in studies comparing gluten-free and gluten-containing foods, the target population is usually adults, not children. It is inappropriate to recommend snack bar consumption to children (as suggested around line 71). The authors should clarify that these products are not recommended for regular inclusion in children’s diets, even if their consumption occurs in real-world settings.

In addition, Reference 10—which forms part of the methodological basis for the selection of children-oriented products—explicitly excludes candies and junk foods. Given that the analyzed cereal bars derive approximately half of their carbohydrate content from sugars, they clearly fall within this category, reinforcing the concern that these products should not be promoted for children.

The authors are strongly encouraged to simulate the impact of these cereal bars within an actual diet (both gluten-free and gluten-containing) for children, to assess whether observed differences in protein or fiber composition have any meaningful impact once integrated into a realistic dietary context.

It is also questionable to include “protein bars” in a study of foods for children (as mentioned near line 71), since their consumption by this population is nutritionally inappropriate.

Another limitation is the narrow geographical focus—the study only covers products from the city of Ontario. Expanding the dataset to a national level (Canada-wide) would significantly improve generalizability. Databases exist that could facilitate such inclusion. The discussion also lacks adequate comparison with similar studies from other countries. A more exhaustive literature review is necessary; I suggest including recent and relevant papers such asDOI: 10.1080/09637486.2024.2397057 and DOI: 10.3390/foods11233839

Regarding the food technology aspects, the analysis is superficial. Only two ingredients (inulin and FOS) are discussed, whereas many cereal bars include other added fibers (e.g., bamboo fiber, vegetable fibers) that could have been analyzed via product labeling. A more detailed formulation-level assessment would strengthen the study.

For these reasons, I do not recommend acceptance of this manuscript for publication in Dietetics (MDPI) in its current form. Substantial revision and refocusing would be required for reconsideration.

Major Comments

1. Introduction

References 1, 2, and 3 are not primary scientific sources. At least reference 3 should be replaced with a more current, peer-reviewed research.
Line 49: The statement about the “positive perception of gluten-free products” lacks any supporting references and has not been previously introduced.
Lines 51–54: The section refers to “recent research,” but Reference 7 (from 2018) is not recent. Please update and support with contemporary literature.

2. Materials and Methods
Out of 464 cereal bars identified, 110 met inclusion criteria, 41 of which were gluten-free. This is a high proportion (1/3) and should be emphasized as a significant finding—especially since gluten-free food availability is often reported as limited by celiac associations.
The use of marketing-based selection criteria is weak. Including consumer survey data could provide a more dietetically relevant perspective, aligning the study better with Dietetics’ scope.
Comparisons were not adjusted for brand formulation differences, which can vary widely. Comparing gluten-free and gluten-containing variants from the same brand would yield more meaningful results.

3. Results
Tables 1 and 2 could be merged to present nutritional composition per 100 g, including energy values for easier comparison.

4. Discussion
The discussion mainly restates findings from previous studies (e.g., References 19 and 20) without proposing hypotheses or explanations for observed differences. The authors should discuss potential technological or compositional factors, such as rheological effects of gluten absence (line 250).
Lines 233–255 include speculative interpretations not supported by data or references.
Line 274: The stated “need for further research” on children’s cereal bars is overstated, given their limited dietary relevance.
Line 277: Only two additives were analyzed, which is insufficient. A broader assessment (e.g., protein sources) could clarify observed differences in protein content.
Line 286: The claim that nutrition labels may not reflect actual composition should be treated cautiously and supported with evidence, since labeling regulations allow only limited deviations.
Line 289: The omission of price data is a missed opportunity. Including pricing could allow correlation analyses with nutritional quality.

5. Conclusion
The final sentence is highly speculative, as nutritional adequacy for children cannot be inferred from label-based composition data alone.

Author Response

Please see the attached document.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript provides a comparative analysis of the nutritional composition of gluten-free and gluten-containing bars marketed to children in Ontario. The paper is interesting and readable, but there are several areas for improvement.

Abstract
The final sentence seems to contradict the previous statements. It shows the superior results of GF bars compared to GC bars, but then states that GF bars are not comparable to GF ones, without explaining why.

Introduction
The introduction contains some inaccuracies that require correction.

Materials and Methods

Some of the criteria aren't strictly related to children. You don't mention how many GF bars there are among the 110 tested.

Results

Some tables need corrections.

Discussions and Conclusions

The assumption that GC bars are better than GF is not well-explained.

For detailed comments, please refer to the attached file.

Comments for author File: Comments.pdf

Author Response

Please see the attached document.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors are encouraged to explicitly include a new point in the section of the Discussion that addresses the study’s limitations. Specifically, it should be acknowledged that snack bars represent only a small component of children’s overall dietary intake, and that no comprehensive dietary assessment was performed to evaluate the potential broader impact of consuming gluten-containing versus gluten-free cereal bars. Highlighting this limitation would help to contextualize the findings and prevent unnecessary concern among readers or the general population regarding the specific role of these products in children’s diets.