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Diet, Insulin Sensitivity, and Postprandial Metabolism (TEF)

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ClinicalTrials.gov Identifier: NCT02939638
Recruitment Status : Completed
First Posted : October 20, 2016
Last Update Posted : August 26, 2019
Sponsor:
Collaborator:
Yale University
Information provided by (Responsible Party):
Physicians Committee for Responsible Medicine

Tracking Information
First Submitted Date  ICMJE October 17, 2016
First Posted Date  ICMJE October 20, 2016
Last Update Posted Date August 26, 2019
Actual Study Start Date  ICMJE October 2016
Actual Primary Completion Date December 2018   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: August 20, 2019)
  • Body weight in kg [ Time Frame: 16 weeks ]
    Anticipated weight-loss for intervention group compared with control group. Weight and height will be combined to report BMI in kg/m^2
  • Fat mass in grams [ Time Frame: 16 weeks ]
    Anticipated weight-loss for intervention group compared with control group.
  • Visceral fat in cm^3 [ Time Frame: 16 weeks ]
    Anticipated weight-loss for intervention group compared with control group.
  • Changes in intramyocellular and/or intrahepatocellular lipid [ Time Frame: 16 Weeks ]
    A subset of participants will be selected for magnetic resonance (MR) spectroscopy studies quantifying hepatic lipid and/or intramyocellular and/or contents in order to provide data regarding possible causal relationships between dietary changes, ectopic lipid, and insulin sensitivity. Selected individuals with varying degrees of insulin-resistance in both groups will be assessed before and after the intervention period. These magnetic resonance spectroscopy (MRS) studies will take place at the Magnetic Research Center at Yale University School of Medicine, New Haven, CT.
  • Insulin resistance [ Time Frame: 16 weeks ]
    Insulin resistance will be assessed by the Homeostatic Model Assessment (HOMA) index.
  • Resting Energy Expenditure (REE) [ Time Frame: 16 weeks ]
    Participants will be asked to report to the laboratory within 60 minutes of waking and after a 12-hour fast. Following 30 minutes of quiet rest in a dimly lit room, pulse, respiratory rate, and body temperature will be measured. REE will be measured for 20 minutes through indirect calorimetry (COSMED Metabolic Company Quark Resting Metabolic Rate (RMR), Chicago, IL) utilizing a ventilated hood system. The laboratory temperature will be maintained at 23 degrees C throughout, and precautions will be taken to minimize any disturbances that could affect the metabolic rate. For premenopausal women, measures will be timed so as to occur in the luteal phase of the menstrual cycle.
  • Postprandial metabolism [ Time Frame: 16 weeks ]
    Participants will be asked to report to the laboratory within 60 minutes of waking and after a 12-hour fast. Postprandial metabolism will be measured for three hours after the standard meal. For premenopausal women, measures will be timed so as to occur in the luteal phase of the menstrual cycle.
Original Primary Outcome Measures  ICMJE
 (submitted: October 18, 2016)
Body weight [ Time Frame: 16 weeks ]
Anticipated weight-loss for intervention group, possibly for control group who choose to take advantage of diet instruction at close of study.
Change History Complete list of historical versions of study NCT02939638 on ClinicalTrials.gov Archive Site
Current Secondary Outcome Measures  ICMJE
 (submitted: August 20, 2019)
  • Beta-cell function as measured by glucose (mmmol/L) [ Time Frame: 16 weeks ]
    A standard meal test will be performed after an overnight fast. Plasma glucose, will be measured at 0, 30, 60, 120, and 180 min for a total of 3-hours over a 16-week period. Glucose, insulin and C-peptide will combined and analyzed to report Beta-cell function.
  • Beta-cell function as measured by insulin (pmol/L) [ Time Frame: 16 weeks ]
    A standard meal test will be performed after an overnight fast. Plasma insulin will be measured at 0, 30, 60, 120, and 180 min for a total of 3-hours over a 16-week period. Glucose, insulin and C-peptide will combined and analyzed to report Beta-cell function.
  • Beta-cell function as measured by C-peptide (ng/mL) [ Time Frame: 16 weeks ]
    A standard meal test will be performed after an overnight fast. Plasma C-peptide will be measured at 0, 30, 60, 120, and 180 min for a total of 3-hours over a 16-week period. Glucose, insulin and C-peptide will combined and analyzed to report Beta-cell function.
  • Microbiome Analysis [ Time Frame: 16 weeks ]
    Microbiome analysis from participant-provided stool sample. Analysis from uBiome Biotechnology company in a subset of participants. Anticipated changes in the dietary intervention group include changes in the microbiome composition that correlate with changes in insulin sensitivity.
  • Endothelial function [ Time Frame: 16 weeks ]
    Endothelial function will be measured using the EndoPAT, a proprietary diagnostic device for functional vascular health assessment, in a subset of participants.
  • Diet Assessment Recall Questionnaire [ Time Frame: 16 weeks ]
    24-hour multi-pass dietary recalls will be used to assess dietary adherence to assist study personnel in working with individuals who need additional teaching or support.
  • The Effect of Fat Quantity & Quality on Body Composition, Insulin Resistance, & Insulin Secretion [ Time Frame: 16 Weeks ]
    Regression Analysis will be used to assess The Effect of Fat Quantity & Quality on Body Composition, Insulin Resistance, & Insulin Secretion
  • The Effect of Carbohydrate Quantity & Quality on Body Composition & Insulin Resistance [ Time Frame: 16 Weeks ]
    Regression Analysis will be used to assess The Effect of Carbohydrate Quantity & Quality on Body Composition & Insulin Resistance
  • The Effect of Protein Quantity & Quality on Body Composition, Insulin Resistance, & Insulin Secretion [ Time Frame: 16 Weeks ]
    Regression Analysis will be used to assess The Effect of Protein Quantity & Quality on Body Composition, Insulin Resistance, & Insulin Secretion
  • Levels of Advanced Glycosylation Endproducts (AGEs) [ Time Frame: 16 Weeks ]
    An AGE reader will be used to measure the Levels of the AGEs in the skin
Original Secondary Outcome Measures  ICMJE
 (submitted: October 18, 2016)
  • Serum lipid concentrations [ Time Frame: 16 weeks ]
    Anticipated improvement in lipid panel for intervention group, possibly for control group who choose to take advantage of diet instruction at close of study.
  • Changes in intramyocellular and/or intrahepatocellular lipid [ Time Frame: 16 weeks ]
    A subset of participants will be selected for MR spectroscopy studies quantifying hepatic lipid and/or intramyocellular and/or contents in order to provide data regarding possible causal relationships between dietary changes, ectopic lipid, and insulin sensitivity. Selected individuals with varying degrees of insulin-resistance in both groups will be assessed before and after the intervention period. These MRS studies will take place at the Magnetic Research Center at Yale University School of Medicine, New Haven, CT.
  • Glucose Tolerance and Insulin resistance [ Time Frame: 16 weeks ]
    An oral glucose tolerance test will be performed for three hours after an overnight fast. Anticipated improvement in insulin sensitivity for intervention group, possibly for control group who choose to take advantage of diet instruction at close of study.
  • Resting Energy Expenditure (REE) [ Time Frame: 16 weeks ]
    Participants will be asked to report to the laboratory within 60 minutes of waking and after a 12-hour fast. Following 30 minutes of quiet rest in a dimly lit room, pulse, respiratory rate, and body temperature will be measured. REE will be measured for 20 minutes through indirect calorimetry (Cosmed Quark RMR, Chicago, IL) utilizing a ventilated hood system. The laboratory temperature will be maintained at 23 degrees C throughout, and precautions will be taken to minimize any disturbances that could affect the metabolic rate. For premenopausal women, measures will be timed so as to occur in the luteal phase of the menstrual cycle.
  • Diet Assessment Recall Questionnaire [ Time Frame: 16 weeks ]
    24-hour multi-pass dietary recalls will be used to assess dietary adherence to assist study personnel in working with individuals who need additional teaching or support.
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
 
Descriptive Information
Brief Title  ICMJE Diet, Insulin Sensitivity, and Postprandial Metabolism
Official Title  ICMJE A Randomized, Controlled Trial on Diet, Insulin Sensitivity, and Postprandial Metabolism
Brief Summary This randomized, controlled trial aims to elucidate the mechanisms by which a plant-based dietary intervention causes weight loss. Using a low-fat, plant-based diet for 16 weeks, along with an untreated control for comparison, the study will measure changes in insulin sensitivity, beta-cell function, postprandial metabolism, and intracellular lipid, and assess their associations with changes in body weight.
Detailed Description

In a 16-week trial, overweight adults will be randomly assigned to two groups. Changes in beta-cell function will be the primary outcome. Changes in insulin sensitivity will be the secondary outcome. Changes in postprandial metabolism, and body weight will be the tertiary outcomes.

The Diet Group will be asked to follow a low-fat, vegan diet and will receive weekly classes and support.

The Control Group will be asked to follow a conventional control diet..

This study conducts a pilot substudy to test the hypothesis that changes in insulin sensitivity and beta-cell function observed in response to a diet intervention correlate with changes in intramyocellular and/or intrahepatocellular lipid. Another sub-study assesses the association between metabolic outcomes and gut microbiome. One additional sub-study is looking for associations between metabolic outcomes and endothelial function.

Study Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Condition  ICMJE
  • Overweight
  • Obesity
  • Insulin Resistance
Intervention  ICMJE
  • Other: Plant-based diet
    Weekly instructions will be given to the participants in the intervention group about following vegan diet.
    Other Name: Vegan diet
  • Other: Control Diet
    Participants will be asked to continue their usual diets for the 16-week study period.
Study Arms  ICMJE
  • Active Comparator: Plant-based diet
    The diet group will be asked to follow a low-fat, vegan diet for 16 weeks
    Intervention: Other: Plant-based diet
  • Active Comparator: Control diet
    Half of the participants will be asked to continue their usual diets for the 16-week study period.
    Intervention: Other: Control Diet
Publications *

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status  ICMJE Completed
Actual Enrollment  ICMJE
 (submitted: March 18, 2019)
220
Original Estimated Enrollment  ICMJE
 (submitted: October 18, 2016)
60
Actual Study Completion Date  ICMJE January 9, 2019
Actual Primary Completion Date December 2018   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • Men and women age ≥18 years of age
  • Body mass index 28-40 kg/m2

Exclusion Criteria:

  1. Diabetes mellitus, type 1 or 2, history of diabetes mellitus or of any endocrine condition that would affect body weight, such as thyroid disease, pituitary abnormality, or Cushing's syndrome
  2. Smoking during the past six months
  3. Alcohol consumption of more than 2 drinks per day or the equivalent, episodic increased drinking (e.g., more than 2 drinks per day on weekends), or a history of alcohol abuse or dependency followed by any current use
  4. Use of recreational drugs in the past 6 months
  5. Use within the preceding six months of medications that affect appetite or body weight, such as estrogens or other hormones, thyroid medications, systemic steroids, antidepressants (tricyclics, monoamine oxidase inhibitors (MAOIs), selective serotonin reuptake inhibitors (SSRIs), antipsychotics, lithium, anticonvulsants, appetite suppressants or other weight-loss drugs, herbs for weight loss or mood, St. John's wort, ephedra, beta blockers
  6. Pregnancy or intention to become pregnant during the study period
  7. Unstable medical or psychiatric illness
  8. Evidence of an eating disorder
  9. Likely to be disruptive in group sessions
  10. Already following a low-fat, vegan diet
  11. Lack of English fluency
  12. Inability to maintain current medication regimen
  13. Inability or unwillingness to participate in all components of the study
  14. Intention to follow another weight-loss method during the trial
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 18 Years and older   (Adult, Older Adult)
Accepts Healthy Volunteers  ICMJE No
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE United States
Removed Location Countries  
 
Administrative Information
NCT Number  ICMJE NCT02939638
Other Study ID Numbers  ICMJE Pro00018983
Has Data Monitoring Committee Yes
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE
Plan to Share IPD: Undecided
Responsible Party Physicians Committee for Responsible Medicine
Study Sponsor  ICMJE Physicians Committee for Responsible Medicine
Collaborators  ICMJE Yale University
Investigators  ICMJE
Principal Investigator: Neal D Barnard, M.D. President
PRS Account Physicians Committee for Responsible Medicine
Verification Date August 2019

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP