Diet, Insulin Sensitivity, and Postprandial Metabolism (TEF)

Physicians Committee for Responsible Medicine

Status: Completed

Conditions: Overweight; Insulin Resistance; Obesity

Treatments: Other: Control Diet; Other: Plant-based diet

Study type: Interventional

Funder types: Other

Identifiers

NCT02939638

Pro00018983

Details and patient eligibility

About

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 body weight, body composition, intramyocellular and/or intrahepatocellular lipid, and changes in association to body weight.

Full description

In a 16-week trial, overweight adults will be randomly assigned to two groups. Changes in body weight, body composition, intramyocellular and/or intrahepatocellular lipid, and changes in association to body weight will be measured among other outcomes.

The Intervention Group will 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 sub-study 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.

Enrollment: 220 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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220 participants in 2 patient groups

Plant-based diet

Active Comparator group

Description:

The diet group will be asked to follow a low-fat, vegan diet for 16 weeks

Treatment:

Other: Plant-based diet

Control diet

Active Comparator group

Description:

Half of the participants will be asked to continue their usual diets for the 16-week study period.

Treatment:

Other: Control Diet