The Safety and Effectiveness of Low and High Carbohydrate Diets

The Safety and Efficacy of Low and High Carbohydrate Diets

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

Study Overview

• Status: Completed
• Conditions: Obesity
• Intervention / Treatment: Behavioral: Low-calorie diet; Behavioral: low-carbohydrate diet

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 Type: Interventional
• Enrollment (Actual): 307
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Colorado
    • Denver, Colorado, United States, 80262
      • University of Colorado
  • Missouri
    • St. Louis, Missouri, United States, 63110
      • Washington University
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • University of Pennsylvania

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
weight change	2 years

Secondary Outcome Measures

Outcome Measure	Time Frame
change in lipids	2 years
blood pressure change	2 years
Ketones	2 years
Endothelial Function	2
change in exercise endurance	2 years
change in renal function	2 years
change in bone density	2 years
change in body composition	2 years

Collaborators and Investigators

• Sponsor: Temple University
• Collaborators: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); National Heart, Lung, and Blood Institute (NHLBI); National Center for Complementary and Integrative Health (NCCIH); Office of Dietary Supplements (ODS)
• Investigators: Principal Investigator: James Hill, PhD, University of Colorado, Denver; Principal Investigator: Holly Wyatt, MD, University of Colorado, Denver; Principal Investigator: Gary D Foster, PhD, University of Pennsylvania

Publications and helpful links

General Publications

• de las Fuentes L, Waggoner AD, Mohammed BS, Stein RI, Miller BV 3rd, Foster GD, Wyatt HR, Klein S, Davila-Roman VG. Effect of moderate diet-induced weight loss and weight regain on cardiovascular structure and function. J Am Coll Cardiol. 2009 Dec 15;54(25):2376-81. doi: 10.1016/j.jacc.2009.07.054.

Study record dates

Study Major Dates

• Study Start: April 1, 2003
• Primary Completion (Actual): March 1, 2008
• Study Completion (Actual): March 1, 2008

Study Registration Dates

• First Submitted: March 9, 2004
• First Submitted That Met QC Criteria: March 9, 2004
• First Posted (Estimate): March 10, 2004

Study Record Updates

• Last Update Posted (Estimate): July 1, 2013
• Last Update Submitted That Met QC Criteria: June 28, 2013
• Last Verified: January 1, 2008

More Information

Terms related to this study

• Keywords: Weight Loss
• Other Study ID Numbers: R01AT001103-01 (U.S. NIH Grant/Contract)