NCT00609271

Brief Summary

The objective of this trial is to examine the long-term effects of a diet low in carbohydrates, as compared to one low in fat, on cardiovascular disease risk factors, including blood pressure (BP), body weight and composition, serum lipids, plasma glucose, insulin, adipocytokines (adiponectin, leptin, resistin), and C-reactive protein (CRP) among obese adults. The investigators will test the following hypotheses: Hypothesis 1: Compared to a low fat diet, a diet low in carbohydrates will reduce systolic and diastolic BP over 12 months; Hypothesis 2: Compared to a low fat diet, a diet low in carbohydrates will reduce body weight, total percent body fat, and waist circumference over 12 months; Hypothesis 3: Compared to a low fat diet, a diet low in carbohydrates will reduce serum levels of LDL-cholesterol and triglycerides and increase serum levels of HDL-cholesterol over 12 months; Hypothesis 4: Compared to a low fat diet, a diet low in carbohydrates will reduce plasma levels of glucose and insulin levels over 12 months; and Hypothesis 5: Compared to a low fat diet, a diet low in carbohydrates will reduce plasma levels of leptin, resistin, and CRP and increase plasma levels of adiponectin over 12 months.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
148

participants targeted

Target at P75+ for not_applicable obesity

Timeline
Completed

Started Jan 2008

Longer than P75 for not_applicable obesity

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

January 1, 2008

Completed
23 days until next milestone

First Submitted

Initial submission to the registry

January 24, 2008

Completed
14 days until next milestone

First Posted

Study publicly available on registry

February 7, 2008

Completed
2.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 1, 2011

Completed
1 year until next milestone

Study Completion

Last participant's last visit for all outcomes

January 1, 2012

Completed
6.9 years until next milestone

Results Posted

Study results publicly available

November 19, 2018

Completed
Last Updated

November 19, 2018

Status Verified

April 1, 2018

Enrollment Period

3 years

First QC Date

January 24, 2008

Results QC Date

April 7, 2017

Last Update Submit

April 25, 2018

Conditions

Outcome Measures

Primary Outcomes (16)

  • Predicted Mean Difference in Body Weight From Baseline, by Assigned Dietary Group

    Predicted mean difference from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences in Lean Mass From Baseline, by Assigned Dietary Group

    Mean Difference in Lean Mass predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences in Fat Mass From Baseline, by Assigned Dietary Group

    Mean Difference in Fat Mass predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences of Waist Circumference From Baseline, by Assigned Dietary Group

    Predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences in Total Cholesterol Level From Baseline by Assigned Dietary Group

    Predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences in LDL Cholesterol Level From Baseline, by Assigned Dietary Group

    Predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences in HDL Cholesterol From Baseline, by Assigned Dietary Group

    Predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences in Total-HDL Cholesterol Ratio From Baseline, by Assigned Dietary Group

    Predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences in Triglycerides From Baseline, by Assigned Dietary Group

    Predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences in Systolic Blood Pressure From Baseline, by Assigned Dietary Group

    Predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Difference in Diastolic Blood Pressure, by Assigned Dietary Group

    Mean Difference in Diastolic Blood Pressure predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values

    12 Months

  • Predicted Mean Difference in Plasma Glucose Level, by Assigned Dietary Group

    Mean Difference in Plasma Glucose Level predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences in Serum Insulin Level From Baseline, by Assigned Dietary Group

    Mean Difference in Serum Insulin Level predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 months

  • Predicted Mean Differences in C-reactive Protein Level From Baseline, by Assigned Dietary Group

    Mean Difference in C-reactive Protein Level predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values

    12 Months

  • Predicted Mean Differences in Serum Creatinine Level From Baseline, by Assigned Dietary Group

    Mean Difference in Serum Creatinine Level predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 Months

  • Predicted Mean Differences of 10-y Framingham Risk Score From Baseline, by Assigned Dietary Group

    Mean Difference in 10-y Framingham Risk Score predicted from random-effects models that included diet, time, and diet-by-time interaction term. Markov-chain Monte Carlo techniques were used to impute missing values.

    12 Months

Study Arms (2)

1

EXPERIMENTAL

low carbohydrate diet

Behavioral: low carbohydrate diet

2

ACTIVE COMPARATOR

low fat diet

Behavioral: low fat diet

Interventions

\<40 grams carbohydrate/day

1
low fat dietBEHAVIORAL

\<30% fat, \<7% saturated fat

2

Eligibility Criteria

Age22 Years - 75 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Men or women aged 22 - 75 years, any race/ethnicity
  • BMI of 30 - 45 k/m2
  • Willing and able to provide informed consent

You may not qualify if:

  • History of self-reported clinical CVD (angina/myocardial infarction, coronary revascularization, heart failure, stroke/transient ischemic attack, peripheral arterial disease)
  • Medical condition in which a low-carbohydrate diet may not be advised (diabetes, renal disease, cancer requiring treatment during the past year, osteoporosis, untreated thyroid disease, gout)
  • Current use of more than 2 antihypertensive or more than 2 cholesterol-lowering medications
  • For women, current pregnancy or breastfeeding or plans to become pregnant during the study period
  • Consumption of more than 21 alcoholic beverages per week
  • Currently on a diet or using prescription weight loss medications, underwent weight loss surgery, and/or experienced weight loss \>15 pounds within 6 months of study entry
  • Plans to move out of the study area (\>1 hour from study site) or difficulty to come to the study site
  • Participation of another household member in the study; employees or persons living with employees of the study
  • Participation in other lifestyle intervention trials currently
  • At the discretion of the study coordinator

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Tulane University, Office of Health Research

New Orleans, Louisiana, 70112, United States

Location

Related Publications (2)

  • Hu T, Yao L, Reynolds K, Niu T, Li S, Whelton P, He J, Bazzano L. The effects of a low-carbohydrate diet on appetite: A randomized controlled trial. Nutr Metab Cardiovasc Dis. 2016 Jun;26(6):476-88. doi: 10.1016/j.numecd.2015.11.011. Epub 2015 Dec 12.

  • Bazzano LA, Hu T, Reynolds K, Yao L, Bunol C, Liu Y, Chen CS, Klag MJ, Whelton PK, He J. Effects of low-carbohydrate and low-fat diets: a randomized trial. Ann Intern Med. 2014 Sep 2;161(5):309-18. doi: 10.7326/M14-0180.

MeSH Terms

Conditions

ObesityCardiovascular Diseases

Interventions

Diet, Carbohydrate-RestrictedDiet, Fat-Restricted

Condition Hierarchy (Ancestors)

OverweightOvernutritionNutrition DisordersNutritional and Metabolic DiseasesBody WeightSigns and SymptomsPathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Diet TherapyNutrition TherapyTherapeuticsDietNutritional Physiological PhenomenaDiet, Food, and NutritionPhysiological Phenomena

Results Point of Contact

Title
Dr. Lydia Bazzano
Organization
Tulane University

Study Officials

  • Lydia A Bazzano, MD, PhD

    Tulane University

    PRINCIPAL INVESTIGATOR

Publication Agreements

PI is Sponsor Employee
Yes

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
OUTCOMES ASSESSOR
Purpose
PREVENTION
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Associate Professor Epidemiology

Study Record Dates

First Submitted

January 24, 2008

First Posted

February 7, 2008

Study Start

January 1, 2008

Primary Completion

January 1, 2011

Study Completion

January 1, 2012

Last Updated

November 19, 2018

Results First Posted

November 19, 2018

Record last verified: 2018-04

Locations