The Metabolic Effects of Different Weight Loss Diets

NCT00422630 | Completed DMC

• 1 other identifier: LNE 595-0107
• Study Type: interventional
• Target: 18
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Metabolic Syndrome X; Obesity; Insulin Resistance; Hypertension; Diabetes

Keywords

Weight loss; Obesity; Metabolic Syndrome; Diet; Hypertension; Diabetes; Cholesterol

Outcome Measures

Primary Outcomes (1)

• Change in insulin sensitivity over time

  Baseline, Inpatient Days 1-19, Inpatient final 2 weeks

Secondary Outcomes (6)

• Change in body weight

  Baseline, Outpatient 2 weeks, inpatient 1-19 days, outpatient 8 weeks and inpatient 2 weeks

• Change in blood sugar levels

  baseline and final inpatient 2 weeks

• Change in blood pressure

  Baseline, Inpatient days 1-19 and inpatient 2 weeks

• Change in cholesterol levels

  Baseline and outpatient 8 weeks

• Change in inflammatory markers

  Baseline, Inpatient days 1-19 and outpatient 2 weeks

Study Arms (3)

Average American Diet

ACTIVE COMPARATOR

Behavioral: Reduced calorie American Diet

The DASH diet

ACTIVE COMPARATOR

Behavioral: The DASH diet

The Low Glycemic Index Diet

ACTIVE COMPARATOR

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

Interventions

The DASH diet BEHAVIORAL

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

The DASH diet

The low glycemic Index Diet BEHAVIORAL

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

The Low Glycemic Index Diet

Reduced calorie American Diet BEHAVIORAL

The reduced-calorie diets will provide at least the Recommended Daily Allowance (RDA) for protein (0.8 g/kg/day).

Average American Diet

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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.)

You may not qualify if:

• 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

Sponsors & Collaborators

• Rockefeller University: lead

Study Sites (1)

Rockefeller University Hospital

New York, New York, 10021, United States

Location

MeSH Terms

Conditions

Metabolic Syndrome; Obesity; Insulin Resistance; Hypertension; Diabetes Mellitus; Weight Loss

Condition Hierarchy (Ancestors)

Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Overweight; Overnutrition; Nutrition Disorders; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Vascular Diseases; Cardiovascular Diseases; Endocrine System Diseases; Body Weight Changes

Study Officials

• Lisa Neff, MD

  Rockefeller University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 12, 2007
• First Posted: January 17, 2007
• Study Start: October 1, 2007
• Primary Completion: February 1, 2010
• Study Completion: February 1, 2010
• Last Updated: October 13, 2011

Record last verified: 2011-10

Locations

US (1)