Effects of Individualized Nutrition Therapy and Continuous Glucose Monitoring on Dietary and Sleep Quality in Individuals with Prediabetes and Overweight or Obesity

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. Authors mention that over all incorporating CGM feedback into nutrition therapy improved diet and sleep quality (In the line 21and 22). However, many data showed that there are not statistically significant such as sugar, fat, vegetable, and plant-based protein. The author needs to clearly specify which diets CGM aims to improve, and which of these diets have actually shown improvement through CGM in this study, achieving the intended outcomes.
2. In line 22and 23, the author showed that the treatment group significantly increased intake of whole grains (p=0.02) and plant-based protein (p=0.02). However, the plant-based proteins were not statistically significant between and within the groups during the study period (in line 294 and 295)
3. The intake of animal protein increased in both control and experimental groups. Why is there a specific mention of the increase in plant protein in the abstract (even though the increase in plant protein showed no significant difference), but not a mention of the increase in animal protein? What evidence in this study supports the idea that the increase in plant protein is more beneficial than the increase in animal protein?
4.  AHEI (Alternate Healthy Eating Index) is an indicator used to assess the quality of the diet. Both the control and experimental groups have relatively low scores, but is it true that normal individuals (those without prediabetes or overweight/obesity) do not have low scores?
5. The results show that the vegetable intake in the treatment group actually decreased. Did the CGM intervention achieve its intended goal? Additionally, effective biochemical test values should be provided to demonstrate that CGM is truly effective.
6. In line 220-223, authors mention the sugar intake was reduced by 12.9 g in the treatment group, whereas it increased by 30 g in the control group. Although not statistically significant, changes in the treatment group support better health, while those in the control group have a negative impact. Regarding the author's statement that the changes in the treatment group support better health outcomes, while the changes in the control group have negative effects, could the author provide data on the biochemical and physiological indicators to support this claim?
7. This study only assessed sleep duration and sleep quality, without evaluating whether there were improvements in biochemical test values. Therefore, it cannot assess whether CGM actually improves these symptoms. The author needs biochemical test values or data on the improvement of pathological symptoms to demonstrate that CGM is effective.

Comments on the Quality of English Language

No comments 

Author Response

1. Authors mention that over all incorporating CGM feedback into nutrition therapy improved diet and sleep quality (In the line 21and 22). However, many data showed that there are not statistically significant such as sugar, fat, vegetable, and plant-based protein. The author needs to clearly specify which diets CGM aims to improve, and which of these diets have actually shown improvement through CGM in this study, achieving the intended outcomes. Thank you for your comment. We revised the manuscript to incorporate more details. Please see lines 21-25 and below.

“Incorporating CGM feedback into nutrition therapy significantly increased whole grain (p=0.02) and plant-based protein intake (p=0.02) in the treatment group, with trends toward increased fruit intake (p=0.07) and a reduced percentage of calories from carbohydrates (p=0.08).”

2. In line 22and 23, the author showed that the treatment group significantly increased intake of whole grains (p=0.02) and plant-based protein (p=0.02). However, the plant-based proteins were not statistically significant between and within the groups during the study period (in line 294 and 295)

Thank you for bringing this to our attention. The manuscript has been updated. Please see lines 345-347 and below:

“These changes were statistically significant within the treatment group (p=0.02) following the intervention but did not reach significance when compared between groups.”

 

3. The intake of animal protein increased in both control and experimental groups. Why is there a specific mention of the increase in plant protein in the abstract (even though the increase in plant protein showed no significant difference), but not a mention of the increase in animal protein? What evidence in this study supports the idea that the increase in plant protein is more beneficial than the increase in animal protein?

 Thank you for asking for clarification. We emphasized the observed increase in plant-based protein in the abstract because the change was statistically significant in the treatment group. We have added references to support why an increase in plant-based protein is more beneficial than an increase in animal protein. This information has been added to the manuscript on lines 399-400. Please also see below:

“Several studies suggest that increasing plant protein intake may offer protective benefits against the progression of prediabetes to type 2 diabetes[53–55]”.

 

4.  AHEI (Alternate Healthy Eating Index) is an indicator used to assess the quality of the diet. Both the control and experimental groups have relatively low scores, but is it true that normal individuals (those without prediabetes or overweight/obesity) do not have low scores?

Thank you for your thoughtful comment. In this study, we specifically evaluated the AHEI within a population of individuals with prediabetes, and our analysis was limited to examining changes in this clinical population. We did not include individuals without prediabetes or overweight/obesity, so we are unable to directly compare AHEI scores to those of metabolically healthy individuals in the general population.

 

5. The results show that the vegetable intake in the treatment group actually decreased. Did the CGM intervention achieve its intended goal? Additionally, effective biochemical test values should be provided to demonstrate that CGM is truly effective.

Thank you for highlighting this important point. We acknowledge that observing positive changes across all food groups would have been ideal, but due to study limitations, comprehensive dietary improvements were not seen in every food category. However, the partial improvements in dietary quality achieved by participants in the treatment group showed a significant impact on their blood glucose control, as detailed in our previous publication. We have now clarified this point in the manuscript, lines 417-427, to more comprehensively reflect these findings. Please see below:

 

“The observed improvements in diet quality among participants in the treatment group were accompanied by significantly better blood glucose management compared to the control group. Our previous analysis showed a significant increase in the percentage of time spent within the target blood glucose range (p = 0.02), as well as significant reductions in mean blood glucose concentration (p < 0.05), glucose management indicator (p = 0.02), percent coefficient of variation for blood glucose (p = 0.01), and percent time spent in high or very high blood glucose ranges (p = 0.04) in the treatment group [62]. These changes were not statistically significant in the control group, suggesting that the improvements in diet quality observed in this study may have contributed to better glycemic control in the treatment group.”

 

6. In line 220-223, authors mention the sugar intake was reduced by 12.9 g in the treatment group, whereas it increased by 30 g in the control group. Although not statistically significant, changes in the treatment group support better health, while those in the control group have a negative impact. Regarding the author's statement that the changes in the treatment group support better health outcomes, while the changes in the control group have negative effects, could the author provide data on the biochemical and physiological indicators to support this claim?

Thank you for your comment. In our previous analysis, we observed significant improvements in the blood glucose control in the treatment group but not the control group. We have referenced these findings in the revised manuscript to support the observed dietary changes and their potential clinical relevance. Please see lines 417-427 and below:

 

“The observed improvements in diet quality among participants in the treatment group were accompanied by significantly better blood glucose management compared to the control group. Our previous analysis showed a significant increase in the percentage of time spent within the target blood glucose range (p = 0.02), as well as significant reduc-tions in mean blood glucose concentration (p < 0.05), glucose management indicator (p = 0.02), percent coefficient of variation for blood glucose (p = 0.01), and percent time spent in high or very high blood glucose ranges (p = 0.04) in the treatment group[62]. These changes were not statistically significant in the control group, suggesting that the improvements in diet quality observed in this study may have contributed to better glycemic control in the treatment group.”

 

7. This study only assessed sleep duration and sleep quality, without evaluating whether there were improvements in biochemical test values. Therefore, it cannot assess whether CGM actually improves these symptoms. The author needs biochemical test values or data on the improvement of pathological symptoms to demonstrate that CGM is effective.

We have included data on better blood glucose control in the treatment group from our previous publication to support this finding. Please see lines 417-427 and below.

 

“The observed improvements in diet quality among participants in the treatment group were accompanied by significantly better blood glucose management compared to the control group. Our previous analysis showed a significant increase in the percentage of time spent within the target blood glucose range (p = 0.02), as well as significant reductions in mean blood glucose concentration (p < 0.05), glucose management indicator (p = 0.02), percent coefficient of variation for blood glucose (p = 0.01), and percent time spent in high or very high blood glucose ranges (p = 0.04) in the treatment group [62]. These changes were not statistically significant in the control group, suggesting that the improvements in diet quality observed in this study may have contributed to better glycemic control in the treatment group.”

Reviewer 2 Report

Comments and Suggestions for Authors

This study examines the effects of integrating continuous glucose monitoring with individualized nutrition therapy on diet and sleep quality. The authors present findings which support the effectiveness of this approach in individuals with prediabetes. Overall, the manuscript has merit, but the methodology and discussion lack clarity.

The method section, specifically Study Intervention was not well described.

1. Provide a better description of the primary and secondary aims and outcomes.
2. Were the participants randomized? 
3. Was the lead in period of no changes in diet 10 days to establish a baseline for all participants?
4. How many additional dietary counseling sessions did the intervention group receive? 2?
5. What was the difference in dietary counseling between groups and when did this start?
6. What was the rationale for have a 20-day intervention?
7. Differentiate groups throughout the manuscript. 

Author Response

• Provide a better description of the primary and secondary aims and outcomes.

Thank you for your comment. We have included more information about the primary and secondary aims of this study in lines 88-92. Please see below:

 

“The primary aim of this study was to evaluate the impact of CGM-guided nutrition therapy on diet quality, as measured by Alternate Healthy Eating Index (AHEI) scores, and on intake of individual food groups among individuals with prediabetes who were overweight or obese. Secondary aims included assessing changes in sleep quality.”

• Were the participants randomized? 

We have included more details on randomizing the participants in lines 123-125. Please see below:

“A total of 30 eligible individuals who consented to the study were randomly assigned to either the treatment (n=15) or control (n=15) group, using an online random number generator.”

• Was the lead in period of no changes in diet 10 days to establish a baseline for all participants?

Thank you for this comment. Yes, the 10-day lead-in period served as a baseline during which participants received no nutrition education and were instructed to follow their usual diet. This allowed us to establish consistent baseline measurements of dietary intake and behavior across all participants prior to initiating the intervention. We have clarified this in the revised manuscript. Please see lines 134-136 and below:

“During the initial 10-day period, participants were instructed to maintain their usual dietary habits. This allowed us to establish consistent baseline measurements of dietary intake and behavior across all participants before beginning the intervention.”

• How many additional dietary counseling sessions did the intervention group receive? 2?

Thank you for requesting clarification. Both groups received the same number of counseling sessions, which took place during visits 2 and 3. This information has been included in the manuscript on lines 136–140. Please see below:

“Participants visited the lab every 10 days over the 30-day study period to replace their CGMs, receive dietary guidance, and consult with a dietitian. Both groups received nutrition education and had the opportunity to ask questions directly to a dietitian during the second and third visits.”

• What was the difference in dietary counseling between groups and when did this start?

We revised the manuscript to better highlight the differences between the groups. This information is included in lines 155 to 16. Please see below:

“Both groups received guidance on recommended serving sizes for each food group, carb choices, and the appropriate amount of carbohydrates per meal [45]. However, only the treatment group received additional personalized feedback based on their CGM data during the second and third visits. The dietitian reviewed food diaries with each participant in the treatment group and, using CGM data, highlighted foods that caused blood glucose spikes. This information was then used to set individualized goals aimed at reducing the frequency of high blood glucose events. The control group did not receive CGM-based feedback or personalized goal-setting based on glucose patterns.”

 

• What was the rationale for have a 20-day intervention?

Thank you for your question. The 20-day intervention period was designed to provide participants with sufficient time to implement dietary changes and observe their effects on blood glucose levels using CGM data. This duration balances the need for meaningful behavioral change with practical considerations of participant burden and study feasibility. This information has been added to manuscript lines 140-14. Please see below:

“The 20-day intervention period was designed to provide participants with sufficient time to implement dietary changes and observe their effects on blood glucose levels using CGM data[41].”

• Differentiate groups throughout the manuscript. 

Thank you for your comment. We have revised the manuscript to ensure that the differences between the treatment and control groups are clearly and consistently described throughout the text, including in the Methods, Results, and Discussion sections.