A Very High Fiber Diet Versus a Low-carbohydrate Diet for Weight Loss

A Very High Fiber Diet Versus a Low-carbohydrate Diet for Weight Loss in Obese Individuals With or Without Type 2 Diabetes

Status

Completed

Phases

Phase 4

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01051674

Enrollment

173

Registered

2010-01-18

Start date

2010-01-31

Completion date

2011-09-30

Last updated

2014-07-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Obesity, Type 2 Diabetes

Keywords

Obesity, Type 2 diabetes, Fiber, Dietary fiber, Low-carbohydrate diet, High protein diet

Brief summary

Using a 2x2 complete factorial design, approximately 140 obese men and women who may or may not have type 2 diabetes will be randomized to one of two conditions (70 in each condition): (a) a high fiber diet, or (b) a low-carbohydrate diet. Participants will be instructed to follow their assigned diets for 1 year. Outcome measures of interest will include participants' BMI, waist circumference, blood lipids (total, HDL, and LDL cholesterol, and triglycerides), C-reactive protein, and gastrointestinal peptides. Participants will be recruited from the Loma Linda and San Bernardino city area in southern California.

Interventions

OTHERHigh fiber vs. low-carbohydrate diets

High fiber diet involves at least 40 grams of dietary fiber or more per day for women and at least 50 grams of dietary fiber per day for men. Low-carbohydrate diet involves less than 120 grams of carbohydrate per day for both men and women.

Study design

Allocation

RANDOMIZED

Intervention model

FACTORIAL

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* BMI 30.0-42.0 kg/m2 * English-speaking

Exclusion criteria

* Pregnancy * Lactation * Acute or chronic infection * Type 1 diabetes * Participation in another trial * Active cancers * Currently using Byetta * Currently on weight loss medication * Weight loss of more than 4 lbs. within the last 3 months * Vegan * Active eating disorder * Gastrointestinal problems that may be worsened by a high fiber intake

Design outcomes

Primary

Measure	Time frame
Weight	1 year

Secondary

Measure	Time frame
Gastrointestinal hormones	1 year
Waist circumference	1 year
C-reactive protein	1 year
Lipid profiles	1 year
Serum insulin	1 year
Hemoglobin A1c	1 year
Blood glucose	1 year

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026