Development of the ‘Healthy Eating Index for Older People’ to Measure Adherence to Dietary Guidelines in Healthy Older New Zealand Adults

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study was conducted to improve the quality of eating habits by analyzing the validity and reproducibility of the Eating Index in Healthy regarding the eating habits of healthy elderly people in New Zealand. It is considered a well-planned result in terms of research design and detailed research methods. It is expected that it can be valuable data for dietary research to improve the health of the elderly. Additional supplementation of the following points may help produce better research results.

 

1. The research subjects include both men and women, but consideration of the differences between men and women is required.

2. Careful consideration is required regarding the limitations in the number of research subjects.

3. It would be helpful for readers to illustrate some of the key results.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding additions in track changes in the re-submitted files.

Comment 1: The research subjects include both men and women, but consideration of the differences between men and women is required.
Response 1: Thank you for this comment. We have added a paragraph into the discussion (lines 443-449).
Comment 2: Careful consideration is required regarding the limitations in the number of research subjects.
Response 2: Yes, we agree that sample size is important, and we touched briefly on the sample size in the discussion (lines 475-476, reference 31). The sample size was based on the primary outcome of the original study (lines 92-95). Fortunately, it was large enough to be used in a validation study as guided by Cade et al (2002) (lines 475-476, reference 31) where a sample size of 100-200 participants is sufficient in a validation study. This study had 100 males and 173 females.
Comment 3: It would be helpful for readers to illustrate some of the key results.
Response 3: Thank you for this suggestion. We are preparing a visual abstract and included a figure in the manuscript showing the mean differences between dietary assessment tools by sex (Figure 2).

Reviewer 2 Report

Comments and Suggestions for Authors

The article is concerning an important issue : the use of simple questionnaires, but validated and lacking only a small part of information is advisable .

The article is well designed and the methodology is correct .

I believe that this article can be interesting for readers and useful for researcher in this field. 

Author Response

Thank you very much for taking the time to review this manuscript.

Comment 1: The article is concerning an important issue: the use of simple questionnaires but validated and lacking only a small part of information is advisable. The article is well designed, and the methodology is correct. I believe that this article can be interesting for readers and useful for researcher in this field.

Response 1: Thank you for this comment. Much effort was put into the manuscript to ensure the validation methods and results were thorough and easy to follow.

Reviewer 3 Report

Comments and Suggestions for Authors

The article focuses on developing an Eating Index for Healthy Older People (EI-HOP) and validating a food frequency questionnaire (FFQ) to measure dietary adherence among older adults in New Zealand.

However, the are mayor concerns about the index:

The choice of food groups included and excluded in the FFQ might introduce bias.

Excluding nutrients like calcium, vitamin D, and food safety components to simplify the index may overlook critical dietary elements for older adults.

Excluding nutrients like calcium, vitamin D, and food safety components to simplify the index may overlook critical dietary elements for older adults.

Please explain these mayor concerns.

Author Response

  

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below, we hope they address your concerns.

Comment 1: The choice of food groups included and excluded in the FFQ might introduce bias.

Response 1: Thank you for your valid comment. The FFQ was designed to capture the whole diet. To ensure all relevant food groups were included, the FFQ was cross checked (with three other questionnaires), pilot tested (with 10 older adults for understanding and readability) and the final question in the FFQ was an open question (to capture any foods not in the FFQ). Refer to line 108 and reference 26 in the manuscript. Part of the process was to match each food item on the FFQ to a food group in the ‘Eating for Healthy Older People’. While most foods were able to be matched up in the adequacy or moderation sections, some food items did not fit. This has been discussed in lines 164-170 (method) and as a limitation in the discussion (lines 481).

Comment 2: Excluding nutrients like calcium, vitamin D, and food safety components to simplify the index may overlook critical dietary elements for older adults.

Response 2: We agree calcium and vitamin D are key nutrients for older people. The aim of this index was simplicity and ease of use. Outside of the research setting the ability to calculate nutrient intakes is limited, hence our decision to exclude these sections. However, we have reported a higher index score was associated with higher calcium intake (lines 285-290). Additionally, this index considers the whole food matrix rather than individual nutrients and the limitation of missing inadequate nutrient intakes is acknowledged in line 373. Vitamin D is not measured completely in the New Zealand food composition database, so was not included in the construct validity data (Supplementary Table 3). We did not measure food safety in the FFQ hence could not include in the index. And ‘preventing constipation’ was covered by the wholegrains question (How often do you choose whole grain breads and cereals? lines 186). We also reported a higher index score associated with a higher fibre intake (lines 285-290)

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

After the review process, the manuscript is suitable for publication

Author Response

Thank you for reviewing our manuscript.