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A Novel Diet-Phenotype Interaction Affecting Body Weight (FRESH Start)

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. Identifier: NCT01303757
Recruitment Status : Completed
First Posted : February 25, 2011
Last Update Posted : February 9, 2016
University of North Carolina, Chapel Hill
Broad Institute
Information provided by (Responsible Party):
David S. Ludwig, MD, PhD, Boston Children’s Hospital

Brief Summary:
The primary aim of the study is to examine insulin secretion as an effect modifier of the efficacy of a low-fat vs. low-glycemic load diet for weight loss among overweight/obese young adults in an 18-month, prospectively stratified, multi-center randomized controlled trial.

Condition or disease Intervention/treatment Phase
Obesity Metabolic Syndrome Behavioral: Dietary counselling Not Applicable

Detailed Description:
In recent years, diets of widely varying composition have been used in the treatment of obesity. While none of these diets has produced consistent, long-term weight loss, some individuals on virtually all types of diets do remarkably well. One explanation for this variation among individuals is differences in motivation and behavior. However, underlying biological differences may also play an important role. Previous work has identified insulin secretion (as quantified by serum insulin concentration at 30 minutes following a standard 75-gram oral glucose load) as an important biological determinant. This randomized-controlled, multi-center trial aims to test the hypothesis that insulin secretion will predict which type of diet will work best for each individual. A total of 160 obese young adults (18 to 40 years) will be assigned to one of two diets: low-fat (60% carbohydrate, 20% fat, 20% protein) or low-glycemic load (45% carbohydrate, 35% fat, 20% protein). Participants will be enrolled at two sites (Children's Hospital Boston or University of North Carolina-Chapel Hill) and assigned to diet groups according to baseline insulin secretion status. The protocol will include an intensive 6-month intervention period and a 12-month follow-up period. Registered dietitians will provide nutrition education and behavioral counseling during group workshops and scheduled telephone calls. In an effort to avoid confounding, close attention will be paid to control for treatment intensity, physical activity prescriptions, and behavioral methods between groups. The primary endpoint will be percent body fat by DXA scan. Secondary endpoints will include cardiovascular and diabetes risk factors. Repeated, 24-hour dietary and physical activity recall interviews will provide process data. Metabolomic profiling and molecular analysis of identified metabolites will be conducted to characterize phenotype and explore potential physiological mechanisms. A successful outcome of this work will inform the practice of "personalized" nutritional therapy, enhancing the ability to select the most efficacious weight loss diet for an individual based on underlying biological differences.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 155 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Novel Diet-Phenotype Interaction Affecting Body Weight
Study Start Date : February 2011
Actual Primary Completion Date : December 2015
Actual Study Completion Date : December 2015

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Body Weight

Arm Intervention/treatment
Experimental: Low glycemic load diet
Low glycemic load diet
Behavioral: Dietary counselling
Active Comparator: Low fat diet
Low fat diet
Behavioral: Dietary counselling

Primary Outcome Measures :
  1. Percent body fat by dual-energy x-ray absorptiometry (DXA) [ Time Frame: 18 months ]

Secondary Outcome Measures :
  1. Triglyceride [ Time Frame: 18 months ]
  2. HDL cholesterol [ Time Frame: 18 months ]
  3. LDL cholesterol [ Time Frame: 18 months ]
  4. C-reactive protein [ Time Frame: 18 months ]
  5. Plasminogen Activator Inhibitor-1 [ Time Frame: 18 months ]
  6. Fasting blood glucose [ Time Frame: 18 months ]
  7. Insulin resistance [ Time Frame: 18 months ]
  8. Blood pressure [ Time Frame: 18 months ]
  9. Trunk fat [ Time Frame: 18 months ]

Other Outcome Measures:
  1. Serum insulin concentration 30 minutes following a standard 75-gram oral glucose load [ Time Frame: 18 months ]
    Effect modification

  2. Metabolomic profile [ Time Frame: 18 months ]
    Effect modification

  3. Insulin sensitivity [ Time Frame: 18 months ]
    Effect modification

  4. Abdominal-to-total fat ratio [ Time Frame: 18 months ]
    Effect modification

  5. Waist-to-hip ratio [ Time Frame: 18 months ]
    Effect modification

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria

  • Aged 18 to 40 years.
  • Body mass index (BMI) ≥ 27 kg/m2.
  • Body weight ≤ 300 lb.
  • Access to a working telephone.
  • Clearance in writing from a primary care provider (i.e., physician or nurse practitioner) to rule out pre-existing medical conditions.
  • Willing and able to attend group workshops (for dietary intervention) on specified evenings.

Exclusion Criteria

  • Physician diagnosis of a major medical illness or eating disorder.
  • Chronic use of any medication that may affect study outcomes (e.g., insulin-sensitizing agents).
  • Current smoking (i.e., 1 cigarette in the past week).
  • Physical, mental, or cognitive handicaps that prevent participation.
  • Another member of the family (i.e., first degree relative) or household participating in the study.
  • Planning to relocate from current area of residence during the proposed timeframe for study participation.
  • If female, planning to become pregnant during the 18 months of the study.

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 identifier (NCT number): NCT01303757

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United States, Massachusetts
Children's Hospital Boston
Boston, Massachusetts, United States, 02115
United States, North Carolina
University of North Carolina, Chapel Hill
Chapel Hill, North Carolina, United States
Sponsors and Collaborators
Boston Children’s Hospital
University of North Carolina, Chapel Hill
Broad Institute
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Study Director: Cara B Ebbeling, PhD Boston Children’s Hospital
Principal Investigator: David S Ludwig, MD, PhD Boston Children’s Hospital
Study Director: Leslie Fischer, PhD UNC Chapel Hill
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Responsible Party: David S. Ludwig, MD, PhD, Director, Obesity Prevention Center, Boston Children’s Hospital Identifier: NCT01303757    
Other Study ID Numbers: 10-04-0156
First Posted: February 25, 2011    Key Record Dates
Last Update Posted: February 9, 2016
Last Verified: February 2016
Keywords provided by David S. Ludwig, MD, PhD, Boston Children’s Hospital:
Additional relevant MeSH terms:
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Metabolic Syndrome
Body Weight
Signs and Symptoms
Insulin Resistance
Glucose Metabolism Disorders
Metabolic Diseases