The Metabolic Effects of Different Weight Loss Diets

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Rockefeller University
ClinicalTrials.gov Identifier:
NCT00422630
First received: January 12, 2007
Last updated: October 12, 2011
Last verified: October 2011
  Purpose

Current estimates suggest that 65% of American adults are overweight or obese. Excess body weight has been associated with an increased risk of a number of metabolic abnormalities, including high blood sugar, high blood pressure, high triglyceride levels, and low HDL ("good") cholesterol levels. Insulin resistance (when the body becomes less sensitive to the blood sugar-lowering hormone insulin, and more of the hormone is needed to keep blood sugar levels under control) also frequently occurs as a result of excess body weight. These abnormalities can all increase the risk of heart disease and other serious medical problems. Individuals who are overweight often have a number of these abnormalities at the same time, a situation which is often called "the metabolic syndrome." Dietary changes, physical activity, and weight loss can lead to improvements in each of the metabolic abnormalities described above. However, the best type of diet for people with the metabolic syndrome is not known. This study has been designed to test the effects of several promising dietary patterns, with and without weight loss, in overweight adults with the metabolic syndrome. Most individuals who have the metabolic syndrome do not know they have the condition, so we will be screening many healthy overweight volunteers to see if they may be eligible.


Condition Intervention
Metabolic Syndrome X
Obesity
Insulin Resistance
Hypertension
Diabetes
Behavioral: The DASH diet
Behavioral: The low glycemic Index Diet
Behavioral: Reduced calorie American Diet

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Dietary Interventions for Insulin Resistance and the Metabolic Syndrome

Resource links provided by NLM:


Further study details as provided by Rockefeller University:

Primary Outcome Measures:
  • Change in insulin sensitivity over time [ Time Frame: Baseline, Inpatient Days 1-19, Inpatient final 2 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Change in body weight [ Time Frame: Baseline, Outpatient 2 weeks, inpatient 1-19 days, outpatient 8 weeks and inpatient 2 weeks ] [ Designated as safety issue: No ]
  • Change in blood sugar levels [ Time Frame: baseline and final inpatient 2 weeks ] [ Designated as safety issue: No ]
  • Change in blood pressure [ Time Frame: Baseline, Inpatient days 1-19 and inpatient 2 weeks ] [ Designated as safety issue: No ]
  • Change in cholesterol levels [ Time Frame: Baseline and outpatient 8 weeks ] [ Designated as safety issue: No ]
  • Change in inflammatory markers [ Time Frame: Baseline, Inpatient days 1-19 and outpatient 2 weeks ] [ Designated as safety issue: No ]
  • Diet satisfaction [ Time Frame: day 88 ] [ Designated as safety issue: No ]

Estimated Enrollment: 18
Study Start Date: October 2007
Study Completion Date: February 2010
Primary Completion Date: February 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Average American Diet Behavioral: Reduced calorie American Diet
The reduced-calorie diets will provide at least the Recommended Daily Allowance (RDA) for protein (0.8 g/kg/day).
Active Comparator: The DASH diet Behavioral: The DASH diet
The DASH diet was originally conceived as the optimal diet for individuals with hypertension, based on epidemiologic and clinical trial data suggesting a beneficial effect of plant-based diets on blood pressure It is a diet rich in fruits, vegetables, whole grains, and low-fat dairy products, with moderate amounts of nuts, legumes, fish, and poultry. Consumption of red meat, sweets, and sugary beverages is limited. As a result, the DASH diet contains more potassium, magnesium, calcium, and fiber and less total fat, saturated fat, cholesterol, simple sugars, and sodium than the average American diet
Active Comparator: The Low Glycemic Index Diet
The carbohydrate content of a low GI diet can vary, but many advocates of low GL popular diets suggest a macronutrient profile that is 40% carbohydrate, 30% protein, and 30% fat. These low GL diets are lower in carbohydrate content and higher in protein content than the average American diet. Low GL diets typically contain ample amounts of fruits and vegetables, moderate quantities of nuts, legumes, lean meats, fish, and reduced-fat dairy products, and scant amounts of refined grains, potatoes, and sweets
Behavioral: The low glycemic Index Diet
The carbohydrate content of a low GI diet can vary, but many advocates of low GL popular diets suggest a macronutrient profile that is 40% carbohydrate, 30% protein, and 30% fat. These low GL diets are lower in carbohydrate content and higher in protein content than the average American diet. Low GL diets typically contain ample amounts of fruits and vegetables, moderate quantities of nuts, legumes, lean meats, fish, and reduced-fat dairy products, and scant amounts of refined grains, potatoes, and sweets

  Show Detailed Description

  Eligibility

Ages Eligible for Study:   18 Years to 45 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Nonsmoking men and premenopausal women, ages 18-45
  • Body mass index ≥ 27 kg/m2
  • Body weight < 200 kg
  • Evidence of insulin resistance, as suggested by any one of the following:
  • Fasting glucose ≥ 100 mg/dL
  • Impaired glucose tolerance, with a glucose concentration of ≥ 140 mg/dL 2 hours after a 75-gram oral glucose challenge
  • A fasting insulin concentration ≥ 9 mIU/L
  • At least two of the following:
  • Waist circumference > 35" in women or > 40" in men
  • Prehypertension or hypertension, with BP > 120/80 mmHg but < 145/90 mmHg on 2 antihypertensive agents or less
  • TG > 150 but < 500 mg/dL
  • HDL < 40 mg/dL in men or < 50 mg/dL in women
  • Willingness to consume only study food and drink for the duration of the study and to be randomized to one of the three diets
  • Willingness to maintain consistent intake of coffee and/or tea during the inpatient periods
  • Willingness to avoid the use of all over-the-counter or prescription vitamins, dietary supplements, and herbal products during the study, with the exception of the multivitamin supplement (Flintstones® Plus Iron.)
  • Willingness to continue current antihypertensive medications at the same dose and schedule throughout the study, unless a change is advised.
  • Willingness to avoid the use of non-steroidal anti-inflammatory drugs including low-dose daily aspirin, for at least ten days prior to the first admission and during each admission.
  • Willingness to avoid the use of acetaminophen (Tylenol) and furosemide (Lasix) for at least 48 hours prior to and during the 24-hour urine collection.
  • Willingness to avoid the use of sulfonamide antibiotics for at least 1 week prior to and during the 24-hour urine collection.

Exclusion Criteria:

  • Current tobacco smoking
  • History of a bleeding disorder
  • Findings suggestive of cardiovascular disease.
  • Blood pressure ≥ 145/90 mmHg after 10 minutes of rest on two or more screening visits, or treatment with three or more antihypertensive agents at any blood pressure.
  • Fasting glucose ≥ 165 mg/dL, glycosylated hemoglobin > 8%, or any treatment with oral hypoglycemic agents, insulin sensitizing agents , insulin, incretin mimetics, amylin analogues, or endocannabinoid receptor antagonists.
  • History of chronic glucocorticoid use, oral glucocorticoid use for more than 5 days in the previous year, or anticipated treatment with oral or intravenous glucocorticoids during the study period.
  • Current treatment with weight loss medications.
  • History of bariatric surgery
  • Current treatment with any cholesterol-lowering medications.
  • Hyperthyroidism or untreated hypothyroidism.
  • Pregnancy, desired pregnancy, or lactation within the study period.
  • Peri- or postmenopausal status.
  • Obstructive sleep apnea.
  • Active gallstone disease
  • Known history of chronic hepatitis, or liver enzymes more than 2.5 times the upper limit of normal
  • Known infection with HIV or confirmed positive test for HIV antibody
  • Inflammatory bowel disease, active cancer, or any other medical condition that may cause significant acute weight loss or gain
  • Sustained weight loss > 5% of body weight in the previous two months, or sustained weight loss > 10% of body weight in the previous six months
  • History of kidney stones
  • Renal disease, as evidenced by a serum creatinine above the normal limit on more than one screening visit
  • Serum calcium, potassium, or magnesium above the normal limit, confirmed on two screening tests
  • Seizure disorder
  • History of any inpatient psychiatric admission within the past two years
  • History of schizophrenia, psychosis, or bipolar disorder
  • History of anorexia nervosa or bulimia nervosa or a history of medical or psychological treatment for an eating disorder
  • Severe binge eating disorder
  • Active moderate to severe depression.
  • History of alcohol or drug abuse within the previous two years
  • History, physical, or laboratory findings suggestive of any other medical or psychological condition that would, in the opinion of the principal investigator, make the candidate ineligible for the study
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00422630

Locations
United States, New York
Rockefeller University Hospital
New York, New York, United States, 10021
Sponsors and Collaborators
Rockefeller University
Investigators
Principal Investigator: Lisa Neff, MD Rockefeller University
  More Information

No publications provided

Responsible Party: Rockefeller University
ClinicalTrials.gov Identifier: NCT00422630     History of Changes
Other Study ID Numbers: LNE 595-0107
Study First Received: January 12, 2007
Last Updated: October 12, 2011
Health Authority: United States: Institutional Review Board

Keywords provided by Rockefeller University:
Weight loss
Obesity
Metabolic Syndrome
Diet
Hypertension
Diabetes
Cholesterol

Additional relevant MeSH terms:
Hypertension
Insulin Resistance
Metabolic Syndrome X
Obesity
Syndrome
Body Weight
Cardiovascular Diseases
Disease
Glucose Metabolism Disorders
Hyperinsulinism
Metabolic Diseases
Nutrition Disorders
Overnutrition
Overweight
Pathologic Processes
Signs and Symptoms
Vascular Diseases

ClinicalTrials.gov processed this record on October 23, 2014