Title: Association between Dietary Inflammatory Index and Ulcerative Colitis: A Case-control
Study
Version: 1 Date: 01 Feb 2025
Reviewer:  Yasmine Y. Bouzid
Reviewer's report:
Reviewer Report
The manuscript titled “Association between Dietary Inflammatory Index and Ulcerative Colitis:
A Case-control Study” uses patients with ulcerative colitis and healthy controls to assess
associations between inflammatory potential of the diet and UC. I would like more information
on the dietary assessment. Some of the results are overstated for a retrospective case-control
study. Comments for the authors are included here:
1. As far as statistical methods, please consider calculating nutrients per 1000 calories to display
diet composition proportional to energy intake (Table 3.2). The UC cases seem to eat less
than controls (nearing statistical significance) and I question whether intake of certain nutrients
appears higher due to greater overall intake. I wonder the effect of UC symptoms on appetite
if you could discuss.
2. Please consider calculating adjusted p-values using the Benjamini Hochberg method: https://
academic.oup.com/jrsssb/article/57/1/289/7035855?login=false. Many nutrients are assessed,
and it is wise to correct for multiple hypothesis testing.
3. For what period were participants asked to estimate their dietary intake? The last year? The last
6 months? Food frequency questionnaires are semi-quantitative and require that study personnel
specify the time for which participants are to estimate their dietary patterns. It’s important to
know the recall period for a retrospective study.
4. Results did not show a significant difference between DII in active UC cases and those in
remission, thus it is overstated to say dietary changes can help cases achieve remission (Line
199-200).
5. “UC risk, incidence, or occurrence” cannot be assessed by the retrospective study design.
Participants did not develop UC during the study period, and without clarification of the period
the FFQ was used to assess, we cannot extrapolate participants’ diet patterns at the time they
developed UC. The design is cross-sectional, therefore only associations can be stated for the
time when dietary data and gastrointestinal health information were collected.
6. Please ensure that wording is consistent for Dietary Inflammatory Index. It’s stated several
times as ‘dietary inflammation index’.
7. Consider stating the limitation that the DII was developed using literature on associations
between diet and systemic inflammation markers, but not gastrointestinal markers.
Title: Association between Dietary Inflammatory Index and Ulcerative Colitis: A Case-control
Study
Version: 1 Date: 01 Feb 2025
Reviewer:  Yasmine Y. Bouzid
Reviewer's report:
Reviewer Report
The manuscript titled “Association between Dietary Inflammatory Index and Ulcerative Colitis:
A Case-control Study” uses patients with ulcerative colitis and healthy controls to assess
associations between inflammatory potential of the diet and UC. I would like more information
on the dietary assessment. Some of the results are overstated for a retrospective case-control
study. Comments for the authors are included here:
1. As far as statistical methods, please consider calculating nutrients per 1000 calories to display
diet composition proportional to energy intake (Table 3.2). The UC cases seem to eat less
than controls (nearing statistical significance) and I question whether intake of certain nutrients
appears higher due to greater overall intake. I wonder the effect of UC symptoms on appetite
if you could discuss.
2. Please consider calculating adjusted p-values using the Benjamini Hochberg method: https://
academic.oup.com/jrsssb/article/57/1/289/7035855?login=false. Many nutrients are assessed,
and it is wise to correct for multiple hypothesis testing.
3. For what period were participants asked to estimate their dietary intake? The last year? The last
6 months? Food frequency questionnaires are semi-quantitative and require that study personnel
specify the time for which participants are to estimate their dietary patterns. It’s important to
know the recall period for a retrospective study.
4. Results did not show a significant difference between DII in active UC cases and those in
remission, thus it is overstated to say dietary changes can help cases achieve remission (Line
199-200).
5. “UC risk, incidence, or occurrence” cannot be assessed by the retrospective study design.
Participants did not develop UC during the study period, and without clarification of the period
the FFQ was used to assess, we cannot extrapolate participants’ diet patterns at the time they
developed UC. The design is cross-sectional, therefore only associations can be stated for the
time when dietary data and gastrointestinal health information were collected.
6. Please ensure that wording is consistent for Dietary Inflammatory Index. It’s stated several
times as ‘dietary inflammation index’.
7. Consider stating the limitation that the DII was developed using literature on associations
between diet and systemic inflammation markers, but not gastrointestinal markers.
Please review this paper.
user
Title: Association between Dietary Inflammatory Index and Ulcerative Colitis: A Case-control
Study
Version: 1 Date: 01 Feb 2025
Reviewer:  Yasmine Y. Bouzid
Reviewer's report:
Reviewer Report
The manuscript titled “Association between Dietary Inflammatory Index and Ulcerative Colitis:
A Case-control Study” uses patients with ulcerative colitis and healthy controls to assess
associations between inflammatory potential of the diet and UC. I would like more information
on the dietary assessment. Some of the results are overstated for a retrospective case-control
study. Comments for the authors are included here:
1. As far as statistical methods, please consider calculating nutrients per 1000 calories to display
diet composition proportional to energy intake (Table 3.2). The UC cases seem to eat less
than controls (nearing statistical significance) and I question whether intake of certain nutrients
appears higher due to greater overall intake. I wonder the effect of UC symptoms on appetite
if you could discuss.
2. Please consider calculating adjusted p-values using the Benjamini Hochberg method: https://
academic.oup.com/jrsssb/article/57/1/289/7035855?login=false. Many nutrients are assessed,
and it is wise to correct for multiple hypothesis testing.
3. For what period were participants asked to estimate their dietary intake? The last year? The last
6 months? Food frequency questionnaires are semi-quantitative and require that study personnel
specify the time for which participants are to estimate their dietary patterns. It’s important to
know the recall period for a retrospective study.
4. Results did not show a significant difference between DII in active UC cases and those in
remission, thus it is overstated to say dietary changes can help cases achieve remission (Line
199-200).
5. “UC risk, incidence, or occurrence” cannot be assessed by the retrospective study design.
Participants did not develop UC during the study period, and without clarification of the period
the FFQ was used to assess, we cannot extrapolate participants’ diet patterns at the time they
developed UC. The design is cross-sectional, therefore only associations can be stated for the
time when dietary data and gastrointestinal health information were collected.
6. Please ensure that wording is consistent for Dietary Inflammatory Index. It’s stated several
times as ‘dietary inflammation index’.
7. Consider stating the limitation that the DII was developed using literature on associations
between diet and systemic inflammation markers, but not gastrointestinal markers.
assistant