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Low-Fat Vegan Diet Versus a Mediterranean Diet on Body Weight

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ClinicalTrials.gov Identifier: NCT03698955
Recruitment Status : Active, not recruiting
First Posted : October 8, 2018
Last Update Posted : March 4, 2019
Sponsor:
Information provided by (Responsible Party):
Physicians Committee for Responsible Medicine

Brief Summary:
This randomized, cross-over trial aims to assess changes in body weight, plasma lipids, insulin sensitivity, and postprandial metabolism with a low-fat, plant-based diet and a Mediterranean diet, both followed for 4 months.

Condition or disease Intervention/treatment Phase
Overweight Obesity Insulin Resistance Other: Plant-based diet Other: Mediterranean Diet Not Applicable

Detailed Description:

In a 36-week cross-over trial, overweight adults will consume a low-fat vegan diet and a Mediterranean diet in two separate 16-week phases. Changes in body weight will be the primary dependent variable. In addition, plasma lipid concentrations, insulin sensitivity, and postprandial metabolism will also be assessed and changes over time will be compared between the two diets.

Participants will be randomly assigned to start either a low-fat vegan diet or a Mediterranean diet for 16 weeks. Both groups will receive weekly classes and support, and will be asked to make no changes to their exercise patterns for the study period. After a 4-week washout period, participants will cross over to the second dietary intervention for another 16 weeks.


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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 62 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Randomized, Cross-Over Trial on the Effects of a Low-Fat Vegan Diet Versus a Mediterranean Diet on Body Weight
Actual Study Start Date : October 22, 2018
Estimated Primary Completion Date : November 2019
Estimated Study Completion Date : November 2019

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Body Weight

Arm Intervention/treatment
Active Comparator: Plant-based diet
The diet group will be asked to follow a low-fat, vegan diet for 16 weeks.
Other: Plant-based diet
Weekly instructions will be given to the participants in the intervention group about following the vegan diet.
Other Name: Vegan diet

Active Comparator: Mediterranean diet
The diet group will be asked to follow a Mediterranean diet for 16 weeks.
Other: Mediterranean Diet
Weekly instructions will be given to the participants in the intervention group about following the Mediterranean diet.




Primary Outcome Measures :
  1. Body weight [ Time Frame: Change in body weight from Baseline at 4 months ]
    Body weight will be assessed at the baseline and at the completion of both interventions.

  2. Plasma lipids [ Time Frame: Change in plasma cholesterol, triglycerides, and HbA1c from Baseline at 4 months ]
    Plasma cholesterol, triglycerides, and HbA1c will be measured in a fasting state.

  3. Insulin sensitivity [ Time Frame: Change in insulin sensitivity from Baseline at 4 months ]
    Insulin sensitivity will be assessed by the HOMA index.

  4. Metabolism [ Time Frame: Changes in metabolism from Baseline at 4 months ]

    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. Postprandial metabolism will be measured for three hours after the standard meal.



Secondary Outcome Measures :
  1. Levels of Advanced Glycosylation Endproducts (AGEs) [ Time Frame: Change in Advanced Glycosylation Endproducts (AGEs) from Baseline at 4 months ]
    An AGE reader will be used to measure the Levels of the AGEs in the skin

  2. Endothelial function [ Time Frame: Change in Endothelial function from Baseline at 4 months ]
    Endothelial function will be measured using the EndoPAT.

  3. Microbiome analysis [ Time Frame: Change in Microbiome from Baseline at 4 months ]
    Microbiome analysis will be performed from participant-provided stool sample. Anticipated changes in the dietary intervention group include changes in the microbiome composition that correlate with changes in insulin sensitivity.



Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

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

Exclusion Criteria:

  • Diabetes mellitus type 1, history of any endocrine condition that would affect body weight, such as thyroid disease, pituitary abnormality, or Cushing's syndrome
  • Smoking during the past six months
  • 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
  • Use of recreational drugs in the past 6 months
  • Use within the preceding six months of medications that affect appetite or body weight, such as estrogens or other hormones, thyroid medications (unstable dose within the preceding 6 months), systemic steroids, antidepressants (tricyclics, MAOIs, SSRIs), antipsychotics, lithium, anticonvulsants, appetite suppressants or other weight-loss drugs, herbs for weight loss or mood, St. John's wort, ephedra, beta blockers
  • Pregnancy or intention to become pregnant during the study period, as verified by self--- - Unstable medical or psychiatric illness
  • Evidence of an eating disorder
  • Likely to be disruptive in group sessions
  • Already following a low-fat vegan diet or Mediterranean diet
  • Lack of English fluency
  • Inability to maintain current medication regimen
  • Inability or unwillingness to participate in all components of the study
  • Intention to follow another weight-loss method during the trial

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03698955


Locations
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United States, District of Columbia
Physicians Committee for Responsible Medicine
Washington, District of Columbia, United States, 20016
Sponsors and Collaborators
Physicians Committee for Responsible Medicine
Investigators
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Principal Investigator: Neal Barnard Physicians Committee for Responsible Medicine

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Responsible Party: Physicians Committee for Responsible Medicine
ClinicalTrials.gov Identifier: NCT03698955     History of Changes
Other Study ID Numbers: Pro00029777
First Posted: October 8, 2018    Key Record Dates
Last Update Posted: March 4, 2019
Last Verified: March 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Physicians Committee for Responsible Medicine:
Plant-based diet
Mediterranean diet
Vegan diet
Metabolism
Insulin sensitivity
Cholesterol
Advanced glycation end-products

Additional relevant MeSH terms:
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Overweight
Insulin Resistance
Body Weight
Signs and Symptoms
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases