The Metabolic Effects of Different Weight Loss Diets

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

Interventions

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

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

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).

Sponsors & Collaborators

• Rockefeller University

  lead OTHER

Principal Investigators

• Lisa Neff, MD · Rockefeller University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

45 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2007-10-31

Primary Completion

2010-02-28

Completion

2010-02-28

Countries

• United States

Study Locations