[version 2; peer review: 2 not approved]
No competing interests were disclosed.
Obesity is a major consequence of malnutrition and significantly contributes to the global burden of chronic diseases. Currently, there are more overweight and obese individuals than underweight individuals. Increased fiber intake can increase insulin sensitivity and fat oxidation. According to research studies, the average dietary fiber consumption is below the recommended value, and the WHO anticipates that the worldwide obesity prevalence has increased in the past ten years.
To evaluate the effect of high dietary fiber intake on insulin resistance, body composition, and weight in overweight and obese middle-aged women.
This hospital-based study evaluated 500 people during phase 1 to identify the prevalence of insulin resistance among overweight and obese middle-aged women. An RCT with intervention and control arms for 180 individuals is being conducted in Phase 2 to determine the effect of increased dietary fiber consumption on insulin resistance, body composition, and weight in overweight or obese middle-aged women. In the intervention group, women were counselled for 15 min and given a tailored food chart including 40 g of fiber. Women in the control arm will receive a typical food care plan with 25 g of fiber, based on their health status. Each engaged woman received fiber nutritional empowerment.
Increasing dietary fiber consumption can improve insulin resistance, body composition, and weight in middle-aged overweight and obese women.
The Clinical Trials Registry of India (CTRI/2022/01/039074) has registered this study as a clinical trial on January 3, 2022
The revised version of this article provides substantial clarifications and updates to improve methodological transparency and scientific accuracy. First, the methods section has been restructured, with Phase 1 (screening for insulin resistance) and Phase 2 (randomized controlled trial) now described under distinct subheadings, along with a schematic representation of the study timeline and intervention schedule. Second, the rationale for focusing exclusively on women has been expanded, with evidence supporting sex-specific differences in insulin resistance and obesity among middle-aged women. Third, outdated terminology such as “roughage” has been replaced with current scientific language to enhance clarity. The study design description has been corrected: the trial is an open-label randomized controlled study, not double-blind, with justification for this choice provided. Clarifications were also added regarding the sample size, dropout rate, and the structured 180-day intervention timeline. The rationale for selecting a 20 g/day difference in fiber intake between groups has been elaborated, drawing on both dietary guidelines and preliminary observational data. To strengthen methodological rigor, details on compliance assessment have been expanded, highlighting the combined use of 24-hour recalls, food frequency questionnaires, compliance checklists, and reinforcement sessions. Finally, the intervention diet is now described as ensuring consistency in soluble and insoluble fiber proportions, minimizing variability across participants. Collectively, these revisions address reviewer concerns and improve the clarity, feasibility, and justification of the study design.
Obesity is a major public health concern worldwide. Urbanization, economic growth, changing lifestyles, and dietary habits have posed a “double burden” of diseases in rapidly developing low- and middle-income countries, such as India.
The decreased incidence of several diseases is associated with fiber-rich diets that have a positive impact on well-being. High-fiber foods can replace energy (calories), which provides low energy density against high-fat foods. The thickening properties of dietary fiber primarily influence satiation and fullness of the stomach. People who consume ample amounts of dietary fiber are at a low risk of developing coronary artery diseases, stroke, hypertension, diabetes, obesity, and certain gastrointestinal diseases compared to those who have minimal fiber intake. A significant improvement was observed in the values of serum lipoprotein and blood pressure, improvement in blood sugar for diabetic entities, and weight reduction by improving the consumption of elevated fiber foods or fiber supplements. Ingestion of soluble fiber enhances immune function.
An increase in the consumption of dietary fiber from a variety of fruits, vegetables, legumes, and whole-grain products will provide various physiological benefits. Dietary fiber, if consumed in acceptable amounts, lowers the risk of several chronic disorders, such as cardiovascular diseases, type 2 diabetes mellitus, obesity, and certain types of cancer. Dietary fiber sources, along with functional fibers, have the additional benefit of organically occurring micronutrients and phytochemicals that may enhance human health. Health benefits of consuming dietary fiber must be actively communicated to the public.
This study focuses on weight reduction by increasing fiber consumption. Recommended fiber intake of 40 2000 kcal is per the Indian Council of Medical Research and National Institute of Nutrition Guidelines.
To determine the effect of fiber intake on insulin resistance, body composition, and weight.
To determine the effect of fiber intake on biochemical parameters. To assess the opinions of women on modified fiber intake.
The present study will be conducted in the OPDs of the medicine, gynaecology, and endocrinology units of a tertiary care hospital in Karnataka, India. This study: 519/2021 was approved by Kasturba Medical College and Kasturba Hospital Institutional Ethics Committee (IEC) on December 19, 2021. The data will be collected on the consent of the patients and the confidentiality will be strictly maintained. Women in the age group between 35-55 years will be screened for insulin resistance at Phase-1 and those women with no contraindication for high fiber consumption and abnormal HOMA-IR will be included in Phase-2.
The primary aim of Phase 1 is to screen middle-aged overweight and obese women to determine the prevalence of insulin resistance.
This phase will be conducted in the Outpatient Departments (OPDs) of Medicine, Gynaecology, and Endocrinology at Kasturba Hospital, Manipal.
A total of 500 women will be screened to assess insulin resistance.
Participants will be categorized into two groups: overweight (BMI 23–24.9 kg/m
2) and obese (BMI ≥ 25 kg/m
2). Each group will have at least 166 participants. The sample size was calculated in accordance with insulin resistance and BMI.
Women aged 35–55 years. Willing to provide informed consent. BMI ≥ 23 kg/m
2.
Women with conditions affecting nutritional status (e.g., tuberculosis, HIV, cancer, organ failure). Women diagnosed with type 2 diabetes mellitus. Individuals with hypertension, thyroid disorders, or any medical condition requiring medications affecting body weight (e.g., thyroxine, diuretics). Pregnant or lactating women. Women already on a weight-loss regime or consuming fiber above the recommended dietary allowance. Women with contraindications for high fiber consumption (e.g., inflammatory bowel disease).
A cross-sectional screening will be undertaken. Women aged
Simultaneously, an in-depth interview will be conducted telephonically for 45 min to understand the barriers of fiber intake among two equal groups of 20 each, consuming low fiber (<20 g) and good fiber (=20 g to 25 g) in phase 1.
To assess the impact of high dietary fiber intake (40 g/day) on insulin resistance, body composition, and weight among overweight and obese women.
Phase 2, the sample size was 180 participants,
180 women will be randomized into:
Intervention Group (n = 90): Receives 40 g/day of fiber with dietary counselling. Control Group (n = 90): Receives 25 g/day of fiber as part of a standard diet care plan.
Sample size for repeated measures ANOVA. Drop out 15% n = 2∗(Z1α/2 + Z1-β)2∗s2∗[1 + (m−1)]∗ρm∗d2 Where, n = sample size z
1-α/2 = 1.96 at α = 0.05 z
1-β = 0.84 at 80% power s = anticipated population standard deviation of the outcome variable. d = clinically significant difference m = number of time points/follow-ups = 2 ρ = intraclass correlation = 0.4 Insulin resistance n = 71 Accounting for a dropout rate of 15%, n = 83 per group As per BMI n = 77 Accounting for a dropout rate of 15%, n = 90 per group The final required sample size was 180 (90 each in the intervention and control groups).
Women from Phase 1 with abnormal HOMA-IR (>2), indicating insulin resistance. Willing to adhere to a high-fiber diet if randomized to the intervention group.
Women unwilling to continue participation or adhere to the high-fiber diet.
Women with no contraindication towards high fiber consumption and abnormal HOMA-IR will be included in Phase-2. Baseline assessment will be done for each woman of both the intervention as well as control groups. Demographic data will be collected such as age, religion, place of residence, type of family, number of family members, marital history, education, occupation and income performa. The anthropometric data using stadiometer (for measuring height), weighing scale (for weight measurement) waist and hip circumference will be documented in the OPD. In the biochemical data, fasting blood glucose (hexokinase method) HbA1c (TINA), serum insulin (ECLIA) and lipid profile (triglyceride-GPO Trinder, HDLdirect homogenous, LDL-enzymatic, total cholesterol-CE-CHOD-POD) will be checked. To assess dietary data, a 24-hr dietary recall and food frequency questionnaire will be used. The data will be analysed using DietCal version 6.3. Physical activity data is assessed by using the GPAQ (Global Physical Activity Questionnaire). Body fat analyser will be used to check visceral fat, subcutaneous fat and muscle mass. Clinical assessment (physical complaints like).
All women in the intervention arm will be counseled for about 15 minutes, and a customized diet chart consisting of high fiber of 40 grams will be provided. Nutritional empowerment on fiber shall be delivered to each woman enrolled. Necessary dietary advice on the modified diet plan and with a motivation to adhere to the diet plan will be communicated only to the intervention group. After the first counselling, on the 15th day, women will be telephonically assessed on their 24-hour recall dietary intake. On the 30th day, the women will be contacted telephonically again to record their 24-hour recall of their dietary intake. Necessary dietary changes on the modified diet plan will be advised, and motivation to adhere to the diet plan will be continued. On the 60th day, the women will be again telephonically contacted to record their 24-hour recall on their dietary intake, and necessary dietary changes on the modified diet plan will be advised, and motivation to adhere to the diet plan will be continued. On the 90th day, as an outcome-based assessment, women will be called to the hospital for the anthropometric data, biochemical data followed by dietary data, a 24-hr dietary recall, food frequency analyzed using DietCal version 6.3, physical activity data assessed by using GPAQ, body fat is analyzed using body fat analyzer and a questionnaire on patient opinion regarding modified diet plan shall be assessed as motivation and adherence towards fiber consumption subjects will be communicated telephonically on the 135th day. From the 136th to the 180th day, there shall not be any conversation regarding dietary modifications. On the 180th day, as a compliance-checking, the women will be again called to the hospital for the anthropometric data, biochemical data followed by dietary data. 24 hr dietary recall, food frequency analyzed using DietCal version 6.3, physical activity data assessed by using GPAQ, body fat analyzed using body fat analyzer and diet compliance on the modified diet plan shall be assessed (
Schematic representation for randomized control trial.
| Control Arm | ||
| Day 1 | Traditional/standard care
|
|
| Day 15 | Nil | |
| Day 30 | Nil | |
| Day 60 | Nil | |
| Day 90
|
|
|
| Intervention Arm | ||
| Day 1 | Intervention
|
Customize the individual-specific diet plan
|
| Day 15, Day 30, Day 60 | Reinforcement
|
Tool 2: 24 hr recall
|
| Day 90 | Outcome assessment
|
|
| Day 135 | Reinforcement (through telephone) | Motivation to follow customised diet plan |
| Day 180 | Checking compliance
|
|
Women in the control arm will get a traditional diet care plan with 25 gm of fiber according to their health condition. Necessary dietary advice will be communicated to the control group on the first visit to the hospital. There shall be no telephonic communication with the control group till the 90th day. On the 90th day, as an outcome-based assessment, women will be called to the hospital for the anthropometric data, biochemical data followed by dietary data, a 24-hour dietary recall, food frequency analyzed using DietCal version 6.3, physical activity data assessed by using GPAQ, and body fat is analyzed using body fat analyzer. On the 180th day, as a compliance-checking, the patient will be again called to the hospital for the anthropometric data, biochemical data followed by dietary data, a 24-hr dietary recall, food frequency analyzed using DietCal version 6.3, physical activity data assessed by using GPAQ, and body fat is analyzed using body fat analyzer (
Repeated Measures ANOVA will be used to evaluate changes in insulin resistance, body composition, and weight over time. SPSS v16.0 will be used for statistical analysis.
Approval obtained from the Institutional Research Committee and Institutional Ethics Committee (IEC). Trial registered with the Clinical Trials Registry of India (CTRI/2022/01/039074). Informed consent was obtained from all participants.
Currently, participants have been recruited for phase-1 and 2, and follow-up for phase-2 is ongoing.
There is limited evidence on the beneficial association between high dietary fiber intake and metabolic indicators, body composition, and weight in middle-aged women who are overweight or obese in the Indian population. This study will focus on improving insulin resistance, body composition, and weight, which will be recorded in participants with high dietary fiber intake. Dietary fiber has various health benefits, with a satiating role in establishing a sense of contentment, lowering cholesterol levels, and decreasing the rise in blood sugar and fat oxidation by lowering body fat content.
An improvement in insulin resistance, body composition, and weight will be recorded in participants with high dietary fiber intake. Good knowledge and practice regarding modified diet plans with high dietary fiber will be addressed to participants. Knowledge regarding barriers/consequences/clinical hindrances in consuming a high-fiber diet will be addressed. Drop out due to non-compliance. Patients adhering to follow the diet plan for a longer period. Limited resources are available to address the importance of inclusion of recommended fiber in the general public since we are only screening patients visiting hospitals.
The study protocol was reviewed and approved by the Institutional Research Committee (IRC) and Institutional Ethics Committee (IEC): 519/2021 was approved by Kasturba Medical College and Kasturba Hospital Institutional Ethics Committee on December 19, 2021, registered under the Clinical Trials Registry- India (CTRI) (CRTI/2022/01/039074). The study will be carried out in compliance with Good Clinical Practice standards. These findings will be published in peer-reviewed journals and presented at international conferences.
All the participants signed a written informed consent form. All methods will be carried out in accordance with the relevant guidelines and regulations.
No data are associated with this article.
Open Source Framework: Effect of high dietary fiber intake on insulin resistance, body composition, and weight among overweight or obese middle-aged women: Study protocol for a double-blind randomized controlled trial, DOI
The supplementary materials available are:
Questionnaire SPIRIT checklist Education Material
Open Source Framework: Checklist for Effect of high dietary fiber intake on insulin resistance, body composition, and weight among overweight or obese middle-aged women: Study protocol for a randomized controlled trial, DOI
We are grateful to the funding agency IMCR-DHR, India.
This is a protocol of a trial comparing a group that will be motivated to eat a high fiber diet to a control group that is not motivated to do so, but only receives information on the benefits of eating fiber. This is a worthwhile endeavor that I fully support. However, the way the protocol has been written down can be improved and the sample size calculation needs correction. Below some points that were not clear to me, or where I have questions regarding the methodology not answered by the protocol.
The second secondary objective is not specific enough. Opinion on what? In phase 1 I have doubt whether a single 24 hour recall is adequate to determine usual intake. I wonder whether a food frequency questionnaire designed for measuring fiber intake would not be more suitable. Is there evidence to support that a single 24 hour recall gives a sufficiently accurate estimate of usual intake of fiber? Are 500 participants in phase 1 enough to provide 180 participants who agree to being randomized in phase 2? This is not explained clearly. It is not clear to me what is meant by “The sample size was calculated in accordance with insulin resistance and BMI.” Please give more details on the sample size calculation. What input was used? What sample size calculation method? The information on the sample size calculation is not complete: two essential parameters for the sample size calculations are s = anticipated population standard deviation of the outcome variable and d = clinically significant difference. The authors do not provide the values they used for these parameters, nor do they justify why the choice for this d and s was made. The sample size formula given cannot be correct and is also not formatted correctly (s2 instead of s
2). I understand the difference in fiber intake between control and treatment groups was changed from 20 g/day to 15 g/day in this new version of the protocol. However, the sample size did not change, while I would expect that a higher sample size would be needed as the effect (d) would be lower with a smaller difference. In regard to the methodology of phase 2: why are the follow-up measurement on day 180 is not done for the control group? This could be explained better.
Phase 2:
Apart from these points, the writing can be improved.
The introduction needs structuring and a complete rewrite. Now a series of statements is strung together without clear order. For instance, the role of the microbiome is mentioned, interspersed with statements on other aspects, giving the introduction a repetitive character. Another example is the second sentence where a statement on fiber and an unrelated statement on obesity are combined into a single sentence without the sentence making clear why they are combined. Similarly, there is the sentence “There are few studies on the utilization of dietary fiber in the treatment of obesity, but further research is required to confirm stronger associations between dietary fiber and obesity”, where “but” implies a contradiction between the first and the second part, while I don’t see the contradiction.
Parts of the protocol are not written out but only given in bullet points. I found this both strange for a paper, and also often unclear. For instance, under strength an limitations: “Good knowledge and practice regarding modified diet plans with high dietary fiber will be addressed to participants”. Knowledge of whom? Of the researcher or the participants? How will this knowledge be addresses?
Is the study design appropriate for the research question?
Partly
Is the rationale for, and objectives of, the study clearly described?
Partly
Are sufficient details of the methods provided to allow replication by others?
Partly
Are the datasets clearly presented in a useable and accessible format?
Not applicable
Reviewer Expertise:
Biostatistics, with nutrition as one of my focus areas
I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.
To minimize potential bias, participants reporting atypical or irregular dietary patterns were excluded, thereby ensuring that the recorded dietary recall reasonably reflected usual intake.
We recognize that a more detailed dietary assessment is essential for evaluating individual-level nutrient adequacy, particularly dietary fiber intake. Accordingly, in the subsequent intervention phase, we plan to implement a structured high-fiber dietary intervention combined with supportive physical activity. Dietary intake will be assessed using three non-consecutive 24-hour recalls along with a validated Food Frequency Questionnaire (FFQ) to capture habitual intake patterns more comprehensively. Physical activity will be assessed using the Global Physical Activity Questionnaire (GPAQ). This integrated approach will enable a more robust assessment of habitual diet while facilitating the evaluation of changes in insulin sensitivity and related metabolic outcomes.
In Phase 1, a total of
Taking this distribution into account, along with the expected prevalence of insulin resistance and potential exclusions and non-participation in the intervention phase, a screening sample of
Published intervention studies examining the effects of dietary fiber on
Phase 2:
I found the protocol somewhat confusing, primarily because the methods section combines both Phase 1 and Phase 2. It would be clearer if each phase were presented separately under distinct subheadings.
Including a schematic diagram of the intervention would greatly aid in understanding the different phases and how they are structured.
The rationale for expecting sex-specific differences in response to the dietary fiber intervention is unclear. Additionally, the purpose of the intervention itself needs to be better justified. Is this study specifically designed for women’s health? If so, the justification for conducting a single-sex study should be clearly articulated.
Some of the language used in the background section appears outdated and would benefit from revision. For example, terms like “roughage” should be updated to reflect current scientific terminology.
The study is described as stratified, randomized, controlled, and double-blind. However, given that the intervention involves dietary advice to achieve 40g of fiber intake compared to 20g, true double-blinding does not seem feasible. Clarification on how blinding is being implemented would be helpful. Additionally, why was a crossover design not considered, as it might have addressed some of these challenges?
There is confusion regarding the sample size. The power calculation suggests 90 participants per group, but the random allocation section mentions 60 per group. This discrepancy needs to be clarified.
The duration of the intervention is also difficult to determine. It appears to be 180 days for the intervention group, but this information is not presented clearly. Providing a concise summary of the study timeline would improve clarity.
There is limited justification for selecting a 20g difference in fiber intake between groups, as well as for the chosen length of the intervention. It would be useful to know if the research team has previously demonstrated success in increasing dietary fiber intake by 20g, as this can be challenging.
Relying solely on 24-hour dietary recalls to assess compliance is concerning, given the known limitations of this method. Are there any plans to include additional compliance measures?
Lastly, will the composition of dietary fiber (i.e., soluble vs. insoluble) be consistent across participants? The metabolic effects of these fiber types can vary significantly, and this should be addressed.
Is the study design appropriate for the research question?
Partly
Is the rationale for, and objectives of, the study clearly described?
No
Are sufficient details of the methods provided to allow replication by others?
No
Are the datasets clearly presented in a useable and accessible format?
No
Reviewer Expertise:
Nutrition and carbohydrate research
I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.
The primary aim of Phase 1 is to screen middle-aged overweight and obese women to determine the prevalence of insulin resistance.
This phase will be conducted in the Outpatient Departments (OPDs) of Medicine, Gynaecology, and Endocrinology at Kasturba Hospital, Manipal.
A total of 500 women will be screened to assess insulin resistance. Participants will be categorized into two groups: overweight (BMI 23–24.9 kg/m²) and obese (BMI ≥ 25 kg/m²). Each group will have at least 166 participants. Women aged 35–55 years. Willing to provide informed consent. BMI ≥ 23 kg/m². Women with conditions affecting nutritional status (e.g., tuberculosis, HIV, cancer, organ failure). Women diagnosed with type 2 diabetes mellitus. Individuals with hypertension, thyroid disorders, or any medical condition requiring medications affecting body weight (e.g., thyroxine, diuretics). Pregnant or lactating women. Women already on a weight-loss regime or consuming fiber above the recommended dietary allowance. Women with contraindications for high fiber consumption (e.g., inflammatory bowel disease).
Participants will undergo a baseline assessment, including:
Fasting blood glucose (hexokinase method). HbA1c (TINA method). Serum insulin (ECLIA). Lipid profile (triglycerides, HDL, LDL, total cholesterol).
24-hour dietary recall and food frequency questionnaire analyzed using DietCal version 6.3.
Global Physical Activity Questionnaire (GPAQ).
20 participants consuming low fiber (<20g/day) and 20 participants consuming moderate fiber (20-25g/day) will be interviewed telephonically for 45 minutes to assess barriers to fiber intake.
To assess the impact of high dietary fiber intake (40g/day) on insulin resistance, body composition, and weight among overweight and obese women.
Randomized, controlled trial. Stratified Block Randomization (9 blocks of 20 participants each). 180 women will be randomized into:
Intervention Group (n=90): Receives 40g/day of fiber with dietary counselling. Control Group (n=90): Receives 25g/day of fiber as part of a standard diet care plan. Women from Phase 1 with abnormal HOMA-IR (>2), indicating insulin resistance. Willing to adhere to a high-fiber diet if randomized to the intervention group. Women unwilling to continue participation or adhere to the high-fiber diet.
All women in the intervention arm will be counseled for about 15 minutes, and a customized diet chart consisting of high fiber of 40 grams will be provided. Nutritional empowerment on fiber shall be delivered to each woman enrolled. Necessary dietary advice on the modified diet plan and with a motivation to adhere to the diet plan will be communicated only to the intervention group. After the first counselling, on the 15th day, women will be telephonically assessed on their 24-hour recall dietary intake. On the 30th day, the women will be contacted telephonically again to record their 24-hour recall of their dietary intake. Necessary dietary changes on the modified diet plan will be advised, and motivation to adhere to the diet plan will be continued. On the 60th day, the women will be again telephonically contacted to record their 24-hour recall on their dietary intake, and necessary dietary changes on the modified diet plan will be advised, and motivation to adhere to the diet plan will be continued. On the 90th day, as an outcome-based assessment, women will be called to the hospital for the anthropometric data, biochemical data followed by dietary data, a 24-hr dietary recall, food frequency analyzed using DietCal version 6.3., physical activity data assessed by using GPAQ, body fat is analyzed using body fat analyzer and a questionnaire on patient opinion regarding modified diet plan shall be ass. Necessaryessed as motivation and adherence towards fiber consumption subjects will be communicated telephonically on the 135th day. From the 136th to the 180th day, there shall not be any conversation regarding dietary modifications. On the 180th day, as a compliance-checking, the women will be again called to the hospital for the anthropometric data, biochemical data followed by dietary data .24hr dietary recall, food frequency analyzed using DietCal version 6.3., physical activity data assessed by using GPAQ, body fat analyzed using body fat analyzer and diet compliance on the modified diet plan shall be assessed.
Control group.
Women in the control arm will get a traditional diet care plan with 25gm of fiber according to their health condition. Necessary dietary advice will be communicated to the control group on the first visit to the hospital. There shall be no telephonic communication with the control group till the 90th day. On the 90th day, as an outcome-based assessment, women will be called to the hospital for the anthropometric data, biochemical data followed by dietary data, a 24-hour dietary recall, food frequency analyzed using DietCal version 6.3, physical activity data assessed by using GPAQ, and body fat is analyzed using body fat analyzer. On the 180th day, as a compliance-checking, the patient will be again called to the hospital for the anthropometric data, biochemical data followed by dietary data, a 24-hr dietary recall, food frequency analyzed using DietCal version 6.3, physical activity data assessed by using GPAQ, and body fat is analyzed using body fat analyzer
Repeated Measures ANOVA will be used to evaluate changes in insulin resistance, body composition, and weight over time. SPSS v16.0 will be used for statistical analysis.
Approval obtained from the Institutional Research Committee and Institutional Ethics Committee (IEC). Trial registered with the Clinical Trials Registry of India (CTRI/2022/01/039074). Informed consent was obtained from all participants.
CONTROL ARM
Day 1
Traditional/standard care
(patient will be called to OPD)
Day 15
Nil
Day 30
Nil
Day 60
Nil
Day 90
(patient will be called to OPD)
Tool 2: 24hr recall and food frequency
Tool 3: GPAQ
FBS, HbA1c, Sr. Insulin and lipid profile
Visceral fat, S/C fat, muscle mass
INTERVENTION ARM
Day 1
Intervention
(patient will be called to OPD)
Customize the individual-specific diet plan
Nutritional counseling
Impart nutritional empowerment on fiber consumption
Handover of diet plan
Day 15
Reinforcement
(through telephone)
Tool 2: 24hr recall
Tool 3: GPAQ
Modification of diet plan (if required)
Motivate to adhere to the intervention
Day 30
Tool 2: 24hr recall
Tool 3: GPAQ
Modification of diet plan (if required)
Motivate to adhere to the intervention
Day 60
Tool 2: 24hr recall
Tool 3: GPAQ
Modification of diet plan (if required)
Motivate to adhere to the intervention
Day 90
Outcome assessment
(patient will be called to OPD)
Tool 2: 24-hour recall and food frequency
Tool 3: GPAQ
Tool 4: Clinical assessment scale
Tool 5: Patient opinion on a modified diet
FBS, HbA1c, Sr. Insulin and lipid profile
Visceral fat, S/C fat, muscle mass
Day 135
Reinforcement (through telephone)
Motivation to follow a customized diet plan
Day 180
Checking compliance
(patient will be called to OPD)
Tool 2: 24-hour recall and food frequency
Tool 3: GPAQ
Tool 4: Clinical assessment scale
Tool 5: Compliance checklist
FBS, HbA1c, Sr. Insulin and lipid profile
Visceral fat, S/C fat, muscle mass
Day 135
Nil
Day180
(patient will be called to OPD)
Tool 2: 24hr recall and food frequency
Tool 3: GPAQ
FBS, HbA1c, Sr. Insulin and lipid profile
Visceral fat, S/C fat, muscle mass
This study is specifically designed for women’s health, as obesity and insulin resistance present distinct physiological and hormonal influences in females. The decision to focus on middle-aged women was based on prior evidence suggesting unique metabolic responses to dietary interventions in this demographic.
This study specifically explores the impact of menopause on metabolic health, highlighting the increased risk of insulin resistance and obesity in women as they transition through menopause. It aligns with your focus on middle-aged women and the unique metabolic responses they experience.
This study investigates how hormonal factors, especially estrogen, affect insulin resistance and fat distribution differently in women, providing key insights into the sex-specific mechanisms that make middle-aged women particularly vulnerable to obesity and metabolic disorders.
Van
We appreciate the suggestion regarding outdated terminology. The term "roughage" and other obsolete language will be revised to align with current scientific terminology.
There was an error in the original study design description. This study is
The final sample size of
The total duration of the intervention is 180 days (6 months) for the intervention group, with structured follow-ups to ensure adherence and assess outcomes. Participants receive customized dietary counseling on Day 1, followed by reinforcement sessions via telephone on Days 15, 30, and 60 to monitor compliance and provide necessary modifications. Outcome assessments are conducted on Day 90 and Day 180, where anthropometric, biochemical, and dietary data are collected. A motivational follow-up is done on Day 135 to encourage continued adherence. The control group follows the same assessment schedule but does not receive interim dietary modifications. This structured timeline ensures a comprehensive evaluation of the intervention’s impact while maintaining participant engagement.
The 20g difference in fiber intake between groups was selected based on existing dietary recommendations and evidence supporting its impact on weight management and metabolic health. The intervention group receives 40g of fiber per 2000 kcal, aligning with the Indian Council of Medical Research (ICMR) and National Institute of Nutrition (NIN) guidelines. In contrast, the control group follows a standard 25g fiber intake. This difference ensures a meaningful contrast while remaining practical for adherence.
The 180-day (6-month) intervention period was chosen to allow sufficient time for stabilizing dietary habits and for metabolic changes, such as improvements in insulin resistance and body composition, to be observed. The feasibility of increasing dietary fiber intake by 20g has been supported by our preliminary observational study (2019), which assessed fiber intake and obesity among 564 women. This study highlighted a significant negative correlation between fiber intake and BMI, reinforcing the need for a structured dietary intervention to promote increased fiber consumption.
Compliance assessment in this study is not solely based on 24-hour dietary recall; multiple tools are incorporated to ensure accuracy and reliability. In addition to the 24-hour recall and food frequency questionnaire, a compliance checklist is used to track adherence to the prescribed dietary plan. Furthermore, patient opinions on the modified diet are collected to assess acceptability and feasibility. Regular reinforcement sessions (via telephone on Days 15, 30, and 60) further help monitor compliance and address challenges.
The study ensures
The primary aim of Phase 1 is to screen middle-aged overweight and obese women to determine the prevalence of insulin resistance.
This phase will be conducted in the Outpatient Departments (OPDs) of Medicine, Gynaecology, and Endocrinology at Kasturba Hospital, Manipal.
A total of 500 women will be screened to assess insulin resistance. Participants will be categorized into two groups: overweight (BMI 23–24.9 kg/m²) and obese (BMI ≥ 25 kg/m²). Each group will have at least 166 participants. Women aged 35–55 years. Willing to provide informed consent. BMI ≥ 23 kg/m². Women with conditions affecting nutritional status (e.g., tuberculosis, HIV, cancer, organ failure). Women diagnosed with type 2 diabetes mellitus. Individuals with hypertension, thyroid disorders, or any medical condition requiring medications affecting body weight (e.g., thyroxine, diuretics). Pregnant or lactating women. Women already on a weight-loss regime or consuming fiber above the recommended dietary allowance. Women with contraindications for high fiber consumption (e.g., inflammatory bowel disease).
Participants will undergo a baseline assessment, including:
Fasting blood glucose (hexokinase method). HbA1c (TINA method). Serum insulin (ECLIA). Lipid profile (triglycerides, HDL, LDL, total cholesterol).
24-hour dietary recall and food frequency questionnaire analyzed using DietCal version 6.3.
Global Physical Activity Questionnaire (GPAQ).
20 participants consuming low fiber (<20g/day) and 20 participants consuming moderate fiber (20-25g/day) will be interviewed telephonically for 45 minutes to assess barriers to fiber intake.
To assess the impact of high dietary fiber intake (40g/day) on insulin resistance, body composition, and weight among overweight and obese women.
Randomized, controlled trial. Stratified Block Randomization (9 blocks of 20 participants each). 180 women will be randomized into:
Intervention Group (n=90): Receives 40g/day of fiber with dietary counselling. Control Group (n=90): Receives 25g/day of fiber as part of a standard diet care plan. Women from Phase 1 with abnormal HOMA-IR (>2), indicating insulin resistance. Willing to adhere to a high-fiber diet if randomized to the intervention group. Women unwilling to continue participation or adhere to the high-fiber diet.
All women in the intervention arm will be counseled for about 15 minutes, and a customized diet chart consisting of high fiber of 40 grams will be provided. Nutritional empowerment on fiber shall be delivered to each woman enrolled. Necessary dietary advice on the modified diet plan and with a motivation to adhere to the diet plan will be communicated only to the intervention group. After the first counselling, on the 15th day, women will be telephonically assessed on their 24-hour recall dietary intake. On the 30th day, the women will be contacted telephonically again to record their 24-hour recall of their dietary intake. Necessary dietary changes on the modified diet plan will be advised, and motivation to adhere to the diet plan will be continued. On the 60th day, the women will be again telephonically contacted to record their 24-hour recall on their dietary intake, and necessary dietary changes on the modified diet plan will be advised, and motivation to adhere to the diet plan will be continued. On the 90th day, as an outcome-based assessment, women will be called to the hospital for the anthropometric data, biochemical data followed by dietary data, a 24-hr dietary recall, food frequency analyzed using DietCal version 6.3., physical activity data assessed by using GPAQ, body fat is analyzed using body fat analyzer and a questionnaire on patient opinion regarding modified diet plan shall be assessed as motivation and adherence towards fiber consumption subjects will be communicated telephonically on the 135th day. From the 136th to the 180th day, there shall not be any conversation regarding dietary modifications. On the 180th day, as a compliance-checking, the women will be again called to the hospital for the anthropometric data, biochemical data followed by dietary data .24hr dietary recall, food frequency analyzed using DietCal version 6.3., physical activity data assessed by using GPAQ, body fat analyzed using body fat analyzer and diet compliance on the modified diet plan shall be assessed.
Control group.
Women in the control arm will get a traditional diet care plan with 25gm of fiber according to their health condition. Necessary dietary advice will be communicated to the control group on the first visit to the hospital. There shall be no telephonic communication with the control group till the 90th day. On the 90th day, as an outcome-based assessment, women will be called to the hospital for the anthropometric data, biochemical data followed by dietary data, a 24-hour dietary recall, food frequency analyzed using DietCal version 6.3, physical activity data assessed by using GPAQ, and body fat is analyzed using body fat analyzer. On the 180th day, as a compliance-checking, the patient will be again called to the hospital for the anthropometric data, biochemical data followed by dietary data, a 24-hr dietary recall, food frequency analyzed using DietCal version 6.3, physical activity data assessed by using GPAQ, and body fat is analyzed using body fat analyzer
Repeated Measures ANOVA will be used to evaluate changes in insulin resistance, body composition, and weight over time. SPSS v16.0 will be used for statistical analysis.
Approval obtained from the Institutional Research Committee and Institutional Ethics Committee (IEC). Trial registered with the Clinical Trials Registry of India (CTRI/2022/01/039074). Informed consent was obtained from all participants.
CONTROL ARM
Day 1
Traditional/standard care
(patient will be called to OPD)
Day 15
Nil
Day 30
Nil
Day 60
Nil
Day 90
(patient will be called to OPD)
Tool 2: 24hr recall and food frequency
Tool 3: GPAQ
FBS, HbA1c, Sr. Insulin and lipid profile
Visceral fat, S/C fat, muscle mass
INTERVENTION ARM
Day 1
Intervention
(patient will be called to OPD)
Customize the individual-specific diet plan
Nutritional counseling
Impart nutritional empowerment on fiber consumption
Handover of diet plan
Day 15
Reinforcement
(through telephone)
Tool 2: 24hr recall
Tool 3: GPAQ
Modification of diet plan (if required)
Motivate to adhere to the intervention
Day 30
Tool 2: 24hr recall
Tool 3: GPAQ
Modification of diet plan (if required)
Motivate to adhere to the intervention
Day 60
Tool 2: 24hr recall
Tool 3: GPAQ
Modification of diet plan (if required)
Motivate to adhere to the intervention
Day 90
Outcome assessment
(patient will be called to OPD)
Tool 2: 24-hour recall and food frequency
Tool 3: GPAQ
Tool 4: Clinical assessment scale
Tool 5: Patient opinion on a modified diet
FBS, HbA1c, Sr. Insulin and lipid profile
Visceral fat, S/C fat, muscle mass
Day 135
Reinforcement (through telephone)
Motivation to follow customised diet plan
Day 180
Checking compliance
(patient will be called to OPD)
Tool 2: 24hr recall and food frequency
Tool 3: GPAQ
Tool 4: Clinical assessment scale
Tool 5: Compliance checklist
FBS, HbA1c, Sr. Insulin and lipid profile
Visceral fat, S/C fat, muscle mass
Day 135
Nil
Day180
(patient will be called to OPD)
Tool 2: 24hr recall and food frequency
Tool 3: GPAQ
FBS, HbA1c, Sr. Insulin and lipid profile
Visceral fat, S/C fat, muscle mass
This study is specifically designed for women’s health, as obesity and insulin resistance present distinct physiological and hormonal influences in females. The decision to focus on middle-aged women was based on prior evidence suggesting unique metabolic responses to dietary interventions in this demographic.
This study specifically explores the impact of menopause on metabolic health, highlighting the increased risk of insulin resistance and obesity in women as they transition through menopause. It aligns with your focus on middle-aged women and the unique metabolic responses they experience.
This study investigates how hormonal factors, especially estrogen, affect insulin resistance and fat distribution differently in women, providing key insights into the sex-specific mechanisms that make middle-aged women particularly vulnerable to obesity and metabolic disorders.
Van
We appreciate the suggestion regarding outdated terminology. The term "roughage" and other obsolete language will be revised to align with current scientific terminology.
There was an error in the original study design description. This study is
The final sample size of
The total duration of the intervention is 180 days (6 months) for the intervention group, with structured follow-ups to ensure adherence and assess outcomes. Participants receive customized dietary counseling on Day 1, followed by reinforcement sessions via telephone on Days 15, 30, and 60 to monitor compliance and provide necessary modifications. Outcome assessments are conducted on Day 90 and Day 180, where anthropometric, biochemical, and dietary data are collected. A motivational follow-up is done on Day 135 to encourage continued adherence. The control group follows the same assessment schedule but does not receive interim dietary modifications. This structured timeline ensures a comprehensive evaluation of the intervention’s impact while maintaining participant engagement.
The 20g difference in fiber intake between groups was selected based on existing dietary recommendations and evidence supporting its impact on weight management and metabolic health. The intervention group receives 40g of fiber per 2000 kcal, aligning with the Indian Council of Medical Research (ICMR) and National Institute of Nutrition (NIN) guidelines. In contrast, the control group follows a standard 25g fiber intake. This difference ensures a meaningful contrast while remaining practical for adherence.
The 180-day (6-month) intervention period was chosen to allow sufficient time for stabilizing dietary habits and for metabolic changes, such as improvements in insulin resistance and body composition, to be observed. The feasibility of increasing dietary fiber intake by 20g has been supported by our preliminary observational study (2019), which assessed fiber intake and obesity among 564 women. This study highlighted a significant negative correlation between fiber intake and BMI, reinforcing the need for a structured dietary intervention to promote increased fiber consumption.
Compliance assessment in this study is not solely based on 24-hour dietary recall; multiple tools are incorporated to ensure accuracy and reliability. In addition to the 24-hour recall and food frequency questionnaire, a compliance checklist is used to track adherence to the prescribed dietary plan. Furthermore, patient opinions on the modified diet are collected to assess acceptability and feasibility. Regular reinforcement sessions (via telephone on Days 15, 30, and 60) further help monitor compliance and address challenges.
The study ensures