Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

First of all, I would like to thank the authors for the presented results of their investigation on dietary habits in judo athletes. I would also like to thank the editor for the opportunity to review this manuscript.

The manuscript entitled "Fasting in judo - between healthy weight control and health hazard: A narrative review" aims to introduce problems related to fasting strategies in judo. The authors present an interesting topic that falls within the aims and scope of Obesity. Since dietary habits have been investigated in sports environments, as well as in judo, consideration of existing knowledge is always welcome.

The work has a good outline and is easy to read, although there is room for improvement in certain details. I would suggest that the authors consider putting their focus just on judo and removing suggestions for non-athletes in the last paragraph in the Introduction section. Otherwise, it is expected to introduce much more literature on non-athletes dietary habits, compare them to those of judo athletes, and even change the title.

Although Ramadan is a good example, it should be mentioned along with others (s), bearing in mind the various fasting approaches of different religions (line 136). Further, it should be considered in the upcoming text. This way, only one group of people (specific religious) is promoted with the tendency of general conclusions.

Finally, I recommend to revise the Future directions subsection focusing on exact recommendation without unnecessary information (e.g. the first sentence).

Good luck!

Author Response

Reviewer 1

First of all, I would like to thank the authors for the presented results of their investigation on dietary habits in judo athletes. I would also like to thank the editor for the opportunity to review this manuscript.

The manuscript entitled "Fasting in judo - between healthy weight control and health hazard: A narrative review" aims to introduce problems related to fasting strategies in judo. The authors present an interesting topic that falls within the aims and scope of Obesity. Since dietary habits have been investigated in sports environments, as well as in judo, consideration of existing knowledge is always welcome.

 

Re. Thank you very much for your positive assessment of our manuscript and the excellent suggestions to improve it. Please find below our replies to all your comments. All changes in the manuscript are highlighted in MS Word’s tracking mode in the tracked version.

 

The work has a good outline and is easy to read, although there is room for improvement in certain details. I would suggest that the authors consider putting their focus just on judo and removing suggestions for non-athletes in the last paragraph in the Introduction section. Otherwise, it is expected to introduce much more literature on non-athletes dietary habits, compare them to those of judo athletes, and even change the title.

 

Re. Thank you for this very relevant suggestion. We modified the last paragraph of the introduction according to your advice. We also removed the section on non-athletes in the Future directions section.

 

Although Ramadan is a good example, it should be mentioned along with others (s), bearing in mind the various fasting approaches of different religions (line 136). Further, it should be considered in the upcoming text. This way, only one group of people (specific religious) is promoted with the tendency of general conclusions.

 

Re. We agree – a too strong focus was on Ramadan. This is primarily owed to the availability of several publications on Ramadan fasting and judo, while similar publications are not available for fasting periods linked to other religions. We highlight this point now in chapter 3:

• “These include religious practices (e.g., Ramadan and other types of religious fasting)…”
• “A few studies on judo athletes exist that looked into intermittent fasting in conjunction with Ramadan, while the literature on other religious fasting practices is scarce.”

 

Finally, I recommend to revise the Future directions subsection focusing on exact recommendation without unnecessary information (e.g. the first sentence).

 

Re. Thank you, the Future directions have been re-written.

We are very grateful for your thorough review and your recommendations that helped us to improve the manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

Abstract:

The authors made a good effort to illustrate the aim and conclusions of the study. However, although this is a narrative review, a brief section explaining how the relevant literature was identified may enhance the reporting clarity and transparency.

 

 

Methodology

A methodology section is currently missing. A brief description of how the literature was identified with a description of inclusion and exclusion criteria will increase the reporting quality of the manuscript.

 

Figure one

The pie chart use may indicate distribution of energy metabolism. If this is true, the authors are advised to add proportions (percentages). If this is not possible, removing the pie chart from the figure is advised.

 

Lines 147 – 149

The authors made the following statements:

‘Rapid weight loss strategies and pronounced dehydration regularly applied by judo athletes (see section 4. Judo, unhealthy dietary strategies and eating disorders) are frequently associated with a compromised performance [44,45].’

Though the writing is clear, advising the reader to skip this section to read a subsequent one might be incoherent and confuse the readers.

 

Lines 162- 164

The authors made the following statements:

‘In this study, long-term TRE (7–12 months) proved to be the most effective strategy to achieve weight loss [39].’

Referring to an evidence using the term ‘ this study’ might be confusing for the readers. It is advised to use more clear language such as ’ the study by Huang et al. ‘ .

 

Lines 180-181

The authors made the following statement:

‘In conclusion, carefully executed types of intermittent fasting do not compromise performance, metabolism and general health.’

 

Can the authors briefly summarize what is meant by carefully executed intermittent fasting?

 

Section: Health risks of rapid weight loss in judo

The authors are encouraged to construct a table summarizing references, type of evidence, year of conducting the study, sample characteristics, summary of the outcome for each identified risk. This is necessary to allow the reader to evaluate the level of evidence and its strength.

 

Lines 256-257

The authors made the following statement:

‘The acute health risks of rapid weight loss are mostly related to hypohydration, which generally can impair cardiovascular, cognitive and motor function’

Does this mean that avoiding dehydration may reduce the risk associated with intermittent fasting? Is this a recommendation for Judo athletes?

 

Lines 400-401

The authors made the following statement:

‘The available studies are mostly based on inadequate research tools, include too many confounding variables, or suffer from a poor research design.’

The authors are highly encouraged to add more context about this statement. Which studies are they referring to? What are the confounders detected? What are the appropriate research designs? This is necessary to inform the readers about the importance of performing future studies while avoiding methodological considerations.

 

Figure 2:

The title is very general and is not representative of the purpose of review (Judo athletes).  

 

Comments on the Quality of English Language

English proofreading is required. 

Author Response

Reviewer 2

Abstract:

The authors made a good effort to illustrate the aim and conclusions of the study. However, although this is a narrative review, a brief section explaining how the relevant literature was identified may enhance the reporting clarity and transparency.

Re. We are very grateful for the thorough review and the relevant recommendations of the reviewer and highly appreciate the positive evaluation of our manuscript.

Methodology

A methodology section is currently missing. A brief description of how the literature was identified with a description of inclusion and exclusion criteria will increase the reporting quality of the manuscript.

Re. Thank you, a methods section outlining the literature search approach has been added (the new section 4.1).

 

Figure one

The pie chart use may indicate distribution of energy metabolism. If this is true, the authors are advised to add proportions (percentages). If this is not possible, removing the pie chart from the figure is advised.

Re. Thank you for this great suggestion – we included the percentages in the figure.

Lines 147 – 149

The authors made the following statements:

‘Rapid weight loss strategies and pronounced dehydration regularly applied by judo athletes (see section 4. Judo, unhealthy dietary strategies and eating disorders) are frequently associated with a compromised performance [44,45].’

Though the writing is clear, advising the reader to skip this section to read a subsequent one might be incoherent and confuse the readers.

Re. We agree and deleted this reference.

Lines 162- 164

The authors made the following statements:

‘In this study, long-term TRE (7–12 months) proved to be the most effective strategy to achieve weight loss [39].’

Referring to an evidence using the term ‘ this study’ might be confusing for the readers. It is advised to use more clear language such as ’ the study by Huang et al. ‘ .

Re. We agree – the statement has been modified accordingly.

Lines 180-181

The authors made the following statement:

‘In conclusion, carefully executed types of intermittent fasting do not compromise performance, metabolism and general health.’

 

Can the authors briefly summarize what is meant by carefully executed intermittent fasting?

Re. Thank you for this suggestion – we extended the text as follows:

“In conclusion, carefully executed types of intermittent fasting do not compromise performance, metabolism and general health. Important factors for maintained performance during intermittent fasting include the avoidance of nutrient deficiencies and severe dehydration and an adequate coordination of fasting intervals with periods of vigorous exercise. Personalized fasting interventions can be efficient strategies for reducing body fat, while maintaining fat-free body mass or muscle mass, thus improving body composition.”

 

Section: Health risks of rapid weight loss in judo

The authors are encouraged to construct a table summarizing references, type of evidence, year of conducting the study, sample characteristics, summary of the outcome for each identified risk. This is necessary to allow the reader to evaluate the level of evidence and its strength.

Re. Thank you; this is an excellent suggestion. Such a table has been added (Table 1).

Lines 256-257

The authors made the following statement:

‘The acute health risks of rapid weight loss are mostly related to hypohydration, which generally can impair cardiovascular, cognitive and motor function’

Does this mean that avoiding dehydration may reduce the risk associated with intermittent fasting? Is this a recommendation for Judo athletes?

Re. We think that avoiding severe hypohydration is an important aspect to avoid health risks when losing weight, yes. Obviously, the loss of water accounts for a great part of the weight reduction commonly achieved with rapid weight loss strategies. It thus will not be easy to convince judo athletes to renounce this habit, unless policies are changed. Still, the promotion of slower weight loss strategies involving less dehydration as alternative, healthier approaches may be welcomed by some athletes. The development of guidelines regarding hypohydration associated with rapid weight loss will be important steps towards the promotion of healthier weight management in judo and other weight-category sports.  

We added in the introduction: “Thus, forms of intermittent fasting may represent healthy alternatives for weight control in judo. Certainly, these alternatives reduce weight more slowly than the approaches commonly applied to achieve rapid weight loss in judo.”

And in the discussion: “Especially clear guidelines considering health risks associated with severe hypohydration as a result of rapid weight loss are urgently needed.”

Lines 400-401

The authors made the following statement:

‘The available studies are mostly based on inadequate research tools, include too many confounding variables, or suffer from a poor research design.’

The authors are highly encouraged to add more context about this statement. Which studies are they referring to? What are the confounders detected? What are the appropriate research designs? This is necessary to inform the readers about the importance of performing future studies while avoiding methodological considerations.

Re. Thank you for this important comment. We now justify this statement better:

• “The available studies are mostly based on inadequate research tools (e.g., the EAT-26), include too many confounding variables (e.g., competition-linked stress, general dietary habits), or suffer from a poor research design. Examples for poor research designs notably include low sample sizes and the lack of controlled, randomized and especially long-term studies.”

 

Figure 2:

The title is very general and is not representative of the purpose of review (Judo athletes). 

Re. We agree and changed title and legend to:

“Risks and opportunities for weight management strategies in judo. Many judo athletes have efficient strategies to change their weight rapidly and apparently without negative health outcomes. However, especially potential long-term health risks associated with those behaviors remain poorly understood. On one hand, the prevention of negative health outcomes of risky weight management approaches in weight-category sports is essential. On the other hand, successfully applied dietary strategies of judo athletes represent opportunities for the promotion of health in both less experienced athletes and overweight/obese people, especially combined with surging scientific evidence on healthy fasting strategies.“

 

English proofreading is required. 

Re. The manuscript has been thoroughly proofread – all changes are indicated in the tracked version of the manuscript.