Fiber-rich Foods to Treat Obesity and Prevent Colon Cancer

Study Overview
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Brief Summary
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The study will target a population at high risk for colorectal cancer, overweight and obese participants with a history of a colon polyp in the past 3 years to test whether a high-legume, high-fiber diet will simultaneously increase weight loss and suppress intestinal biomarkers of cancer risk compared to a control diet (healthy American). In addition, it will explore potential mechanisms through which the high-legume intervention diet facilitates weight loss and intestinal health.

Detailed Description
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The goal of the research is to conduct a clinical trial featuring study-provided pre-portioned entrées (2 entrées per day months 1-3, 1 entrée per day months 4-6) and strategic nutritional instruction to guide participants to integrate legumes into a healthy high-fiber diet pattern. The research will target a population at high risk for colorectal cancer, overweight and obese participants with a history of a colon polyp in the past 3 years, to test whether a high-legume, high-fiber diet will simultaneously increase weight loss and suppress intestinal biomarkers of cancer risk compared to a control diet (healthy American). In addition, it will explore potential mechanisms through which the high-legume intervention diet facilitates weight loss and intestinal health.

Official Title
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Fiber-rich Foods to Treat Obesity and Prevent Colon Cancer

Conditions
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Colon Cancer, Obesity

Intervention / Treatment
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* Dietary Supplement: Experimental: High Fiber Diet (HFD)
* Dietary Supplement: Healthy American Diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: free-living adults 40-75 yrs. old BMI 25-40 kg/m2 colonoscopy within 3 years that found ≥1 adenoma >0.5 cm English speaking, ambulatory, able to pick up food, participate in clinical exams and laboratory tests - able to provide informed consent Exclusion Criteria: serious medical condition (e.g., cancer, heart disease, kidney disease, diabetes,) history of CRC, bowel resection, polyposis syndrome, or inflammatory bowel disease smoked regularly in the past year dietary restrictions substantially limiting compliance (e.g., must be willing to be randomized to either diet) planning on substantially changing usual exercise behavior in the next 6 mos regular use of medication that may alter inflammation markers, insulin, glucose, or gut function (e.g., non-steroidal anti-inflammatory drugs, antibiotics, insulin, steroids) pregnant women, breast feeding women, or women planning pregnancy within the year of active study participation

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High Fiber Diet (HFD)<br>High Fiber Diet (HFD) will add approximately 25-30 grams of dietary fiber/d from legume dishes. | Dietary Supplement: Experimental: High Fiber Diet (HFD)<br>* Experimental: High Fiber Diet (HFD) pre-portioned entrées for two meals/d in mos. 1-3, and one meal/d in mos. 4-6. Participants continue on their respective diets in mos. 7-12 but assume responsibility for food preparation. The HLD will contain approximately 250g of legumes per day ( 1 ½ cups cooked) in months 1-3 provided in two pre-portioned single serving entrées (i.e.  125g each). A study nutritionist will provide in-person and written guidance for including sides that are nutritionally balanced with energy intake to lose 1-2 lbs. /wk.<br>|
| Active Comparator: Healthy American Diet<br>Healthy American Diet pre-portioned meal replacement entrées with legumes replaced by lean chicken/meat. | Dietary Supplement: Healthy American Diet<br>* Healthy American Diet pre-portioned meal replacement entrées with legumes replaced by lean chicken/meat. A study nutritionist will provide in-person and written guidance for including sides that are nutritionally balanced with energy intake to lose 1-2 lbs. /wk.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body weight measured in pounds | Participants will have their body weight measured in light clothing without shoes on a regularly calibrated digital scale | 6 months | 
| Ki-67+ level | Colonic mucosal proliferative marker Ki-67+ will be measured | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body weight measured in pounds | Participants will have their body weight measured in light clothing without shoes on a regularly calibrated digital scale | 12 months | 
| Ki-67+ level | Colonic mucosal proliferative marker Ki-67+ will be measured | 12 months | 
| Gut transit time | Gut transit time will be assessed using an indigestible single-use SmartPill capsule, a receiver, and display software. | 6 months | 
| Fasting plasma insulin level | Biomarker of insulin resistance - fasting plasma insulin - will be measured by blood test | 6 months | 
| Fasting plasma insulin level | Biomarker of insulin resistance - fasting plasma insulin - will be measured by blood test | 12 months | 
| Fasting plasma glucose level | Biomarker of insulin resistance - fasting plasma glucose - will be measured by blood test | 6 months | 
| Fasting plasma glucose level | Biomarker of insulin resistance - fasting plasma glucose - will be measured by blood test | 12 months | 
| Serum C-reactive protein | Systemic inflammation indicator - serum C-reactive protein - will be measured by blood test | 6 months | 
| Serum C-reactive protein | Systemic inflammation indicator - serum C-reactive protein - will be measured by blood test | 12 months | 
| CD3+ intraepithelial lymphocytes count | Colonic mucosal inflammatory biomarker - CD3+ intraepithelial lymphocytes - will be measured | 6 months | 
| CD3+ intraepithelial lymphocytes count | Colonic mucosal inflammatory biomarker - CD3+ intraepithelial lymphocytes - will be measured | 12 months | 
| CD68+ lamina propia macrophages count | Colonic mucosal inflammatory biomarker - CD68+ lamina propia macrophages - will be measured | 6 months | 
| CD68+ lamina propia macrophages count | Colonic mucosal inflammatory biomarker - CD68+ lamina propia macrophages - will be measured | 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Fiber-rich Foods, Legumes, Weight loss, Intestinal health, Cancer prevention