We're building a better ClinicalTrials.gov. Check it out and tell us what you think!
ClinicalTrials.gov Menu

OmniHeart Trial: Macronutrients and Cardiovascular Risk

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00051350
Recruitment Status : Completed
First Posted : January 13, 2003
Last Update Posted : October 4, 2018
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Johns Hopkins University

Brief Summary:
To compare the effects on blood pressure and plasma lipids of three different diets--a carbohydrate-rich diet, a protein-rich diet, or a diet rich in unsaturated fat.

Condition or disease Intervention/treatment Phase
Cardiovascular Diseases Heart Diseases Atherosclerosis Hypertension Other: CARB Not Applicable

Detailed Description:


While there is widespread consensus that the optimal diet to reduce cardiovascular risk should be low in saturated fat, the type of macronutrient that should replace saturated fat (carbohydrate, protein or unsaturated fat) is a major, unresolved research question with substantial public health implications. The study will evaluate these three dietary approaches by studying their effects on established coronary risk factors and a selected group of emerging risk factors.


The study design was a randomized, three period cross-over feeding study that compared the effects on blood pressure and plasma lipids of a carbohydrate-rich diet patterned after the DASH diet (CARB) to two other diets, one rich in protein (PROTEIN) and another rich in unsaturated (UNSAT) fat, predominantly monounsaturated fat. The DASH diet has been shown to reduce blood pressure and LDL-cholesterol substantially, and is currently recommended by policy makers. During a one week run-in, all participants were fed samples of the three study diets (CARB, PROTEIN and UNSAT). Using a three period cross-over design, participants were then randomly assigned to the CARB, PROTEIN or UNSAT diet. Each feeding period lasted six weeks; a washout period of at least two weeks separated each feeding period. Throughout feeding (run-in and the three intervention periods), participants were fed sufficient calories to maintain their weight. Trial participants were 30 years of age or older, with systolic blood pressure of 120-159 mmHg or diastolic blood pressure of 90-99 mmHg. Primary outcomes variables were blood pressure and the established plasma lipid risk factors (LDL-C, HDL-C and triglycerides). Secondary outcomes include total cholesterol, apolipoproteins VLDL-apoB, VLDL-apoCIII, apolipoprotein B, non-HDL cholesterol, and lipoprotein(a).

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 164 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: Individuals were randomized to a sequence of 3 diets (CARB, UNSAT, PROTEIN)
Masking: Single (Outcomes Assessor)
Masking Description: Outcome assessors were unaware of diet sequence.
Primary Purpose: Prevention
Official Title: Macronutrients and Cardiovascular Risk
Actual Study Start Date : May 2002
Actual Primary Completion Date : March 2008
Actual Study Completion Date : March 2008

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Placebo Comparator: CARB
Diet rich in carbohydrate
Other: CARB
Other Names:

Active Comparator: UNSAT
Diet rich in unsaturated fat
Other: CARB
Other Names:

Active Comparator: PROTEIN
Diet rich in protein
Other: CARB
Other Names:

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   30 Years to 100 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion criteria:

  • Healthy adults
  • Aged 30 years and older
  • Systolic blood pressure of 120 to 159 mm Hg or a diastolic blood pressure of 80 to 99 mm Hg.

Exclusion criteria:

  • Diabetes
  • Active or prior Cardiovascular disease (CVD)
  • LDL cholesterol greater than 220 mg/dL (>5.70 mmol/L)
  • Fasting triglycerides greater than 750 mg/dL (>8.48 mmol/L)
  • Weight more than 350 lb (>159 kg)
  • Taking medications that affect blood pressure or blood lipid levels
  • Unwillingness to stop taking vitamin and mineral supplements
  • Alcoholic beverage intake of more than 14 drinks per week.

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): NCT00051350

Sponsors and Collaborators
Johns Hopkins University
National Heart, Lung, and Blood Institute (NHLBI)
Layout table for investigator information
Study Chair: Lawrence Appel Johns Hopkins University
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Layout table for additonal information
Responsible Party: Johns Hopkins University
ClinicalTrials.gov Identifier: NCT00051350    
Other Study ID Numbers: NA_00069360
R01HL067098 ( U.S. NIH Grant/Contract )
First Posted: January 13, 2003    Key Record Dates
Last Update Posted: October 4, 2018
Last Verified: October 2018

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
Layout table for MeSH terms
Cardiovascular Diseases
Heart Diseases
Vascular Diseases
Arterial Occlusive Diseases