We updated the design of this site on December 18, 2017. Learn more.
ClinicalTrials.gov Menu

The Safety and Effectiveness of Low and High Carbohydrate Diets

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: NCT00079547
Recruitment Status : Completed
First Posted : March 10, 2004
Last Update Posted : July 1, 2013
Information provided by (Responsible Party):

Study Description
Brief Summary:
This study will compare the safety and the effectiveness of a low carbohydrate diet (Atkins diet) with a high carbohydrate diet (conventional USDA diet).

Condition or disease Intervention/treatment Phase
Obesity Behavioral: Low-calorie diet Behavioral: low-carbohydrate diet Phase 4

Detailed Description:

Despite the considerable mass appeal of popular diet books, such diet approaches lack data to support their efficacy and safety. Despite its widespread use for more than 30 years, the Atkins diet has never been evaluated in a large, randomized, controlled trial. This study will assess the short-term and long-term clinical effects of a low-carbohydrate diet and a high-carbohydrate diet in overweight and obese men and women.

Participants in this study will be randomly assigned to the Atkins diet (low-carbohydrate, unlimited fat and protein) or a conventional USDA diet (high-carbohydrate, low-fat). The study will evaluate the effects of each dietary approach on changes in: 1) weight and body composition; 2) metabolic and organ function; and 3) exercise tolerance. Each participant will be enrolled in the study for 2 years.

Study Design

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 307 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: The Safety and Efficacy of Low and High Carbohydrate Diets
Study Start Date : April 2003
Primary Completion Date : March 2008
Study Completion Date : March 2008
Arms and Interventions

Arm Intervention/treatment
Active Comparator: 1
Low-calorie diet
Behavioral: Low-calorie diet
low-calorie diet
Experimental: 2
Low-carbohydrate diet
Behavioral: low-carbohydrate diet
low-carbohydrate diet

Outcome Measures

Primary Outcome Measures :
  1. weight change [ Time Frame: 2 years ]

Secondary Outcome Measures :
  1. change in lipids [ Time Frame: 2 years ]
  2. blood pressure change [ Time Frame: 2 years ]
  3. Ketones [ Time Frame: 2 years ]
  4. Endothelial Function [ Time Frame: 2 ]
  5. change in exercise endurance [ Time Frame: 2 years ]
  6. change in renal function [ Time Frame: 2 years ]
  7. change in bone density [ Time Frame: 2 years ]
  8. change in body composition [ Time Frame: 2 years ]

Eligibility Criteria

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.

Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria

  • Body mass index between 30 and 40
  • Live and work within 1 hour of the study site
  • Stable psychological status

Exclusion criteria

  • History of heart disease, heart attack, or stroke
  • Blood pressure >140/90 mmHg
  • Abnormal cholesterol levels
  • Significant psychiatric illness
  • Any medication that affects weight or metabolic rate
  • Presence or history of a chronic disease that is known to affect appetite, food intake, or metabolism (i.e., diabetes, thyroid disease, or cancer)
  • Currently using antidepressants, steroids, tobacco, or illegal drugs
  • Pregnant, breastfeeding, or planning pregnancy
  • 10 lb change in weight within 6 months of study entry
  • History of malignant arrhythmias or cerebrovascular, renal, or hepatic disease
  • History of protein wasting diseases or gout
  • Severe arthritis
  • Osteoporosis
  • Certain types of hormone replacement therapy
  • Currently following a vegetarian diet
Contacts and Locations

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): NCT00079547

United States, Colorado
University of Colorado
Denver, Colorado, United States, 80262
United States, Missouri
Washington University
St. Louis, Missouri, United States, 63110
United States, Pennsylvania
University of Pennsylvania
Philadelphia, Pennsylvania, United States, 19104
Sponsors and Collaborators
Temple University
National Center for Complementary and Integrative Health (NCCIH)
Office of Dietary Supplements (ODS)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Gary D Foster, PhD University of Pennsylvania
Principal Investigator: Holly Wyatt, MD University of Colorado, Denver
Principal Investigator: James Hill, PhD University of Colorado, Denver
Principal Investigator: Samuel Klein, MD Washington University School of Medicine
More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Temple University
ClinicalTrials.gov Identifier: NCT00079547     History of Changes
Other Study ID Numbers: R01AT001103-01 ( U.S. NIH Grant/Contract )
First Posted: March 10, 2004    Key Record Dates
Last Update Posted: July 1, 2013
Last Verified: January 2008

Keywords provided by Temple University:
Weight Loss