The Metabolic Effects of Different Weight Loss Diets

Completed · Not applicable

Conditions studied: Metabolic Syndrome X, Obesity, Insulin Resistance, Hypertension, Diabetes

In brief

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.

Key facts

Study ID

NCT00422630

Run by

Rockefeller University

People needed

18

Starts

2007-10-01

Expected to finish

2010-02-01

Last updated by the study team

2011-10-13

Who can join

Age: 18 and older, up to 45. Sex: any. Healthy volunteers: accepted.

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.)
• 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.

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
• 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

Where it is running

• Rockefeller University Hospital — New York, New York, United States

Full record on ClinicalTrials.gov

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