Glycemic Load, Metabolism & Obesity in Pregnancy (PANS)
The purpose of the study is to determine if a low glycemic load diet reduces the gain of body fat and insulin resistance during the last half of pregnancy in obese women.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Prevention
|Official Title:||Dietary Glycemic Load & Metabolism in Obese Pregnant Women|
- maternal body fat gain [ Time Frame: 20-34 weeks gestation ] [ Designated as safety issue: No ]Changes in total body fat as measured by air displacement between 20 to 34 weeks gestation
- Insulin Resistance [ Time Frame: 20-34 weeks gestation ] [ Designated as safety issue: No ]Changes in insulin resistance measured during an oral glucose tolerance test between 20 to 34 weeks gestation.
|Study Start Date:||July 2005|
|Study Completion Date:||December 2009|
|Primary Completion Date:||December 2009 (Final data collection date for primary outcome measure)|
Experimental: Low Glycemic Load Diet
Counseled to consume a diet with a low or higher intake of carbohydrate sources that cause rapid or significant intakes in blood glucose. The average glycemic load of the diet should be less than 55 per 1000 calories or greater than 55 per 1000 calories.
Other: Low Glycemic Load diet
Pregnant women were counseled to consume a diet with a glycemic load per 1000 kcal of less than 55.
Other Name: LGL Diet
Experimental: Low Fat Diet
Pregnant women were counseled to consume a diet providing less that 25% of the energy as fat.
Other: Low Fat Diet
Pregnant women were counseled to consume diets providing less than 25% of the energy as fat.
Other Name: LF Diet
Obese women will be recruited to participate in the study between 14-18 weeks gestation. After determining usual dietary intakes, visceral fat thickness, and the metabolic response to a 100g oral glucose tolerance test (OGTT) at 20 weeks gestation, 45 of the women will be randomly assigned to a low glycemic load (GL) diet and 65 women to a regular low fat diet (current standard care). They will follow their assigned diet for the last 20 weeks of gestation. A dietitian will advise the women and will monitor them throughout the study. At 28 and 34 weeks gestation, the women will come to the General Clinical Research Center (GCRC) at San Francisco General Hospital in the fasting state and the hormonal and metabolic response will be measured to another 100g oral glucose tolerance test (OGTT), and total body fat will be measured. Additional measurements include: 1) longitudinal measurements of maternal visceral fat thickness and fetal size and adiposity at 20 and 34 weeks gestation by ultrasound, 2) collection of cord blood and placental tissue, and 3) measurement of neonatal body composition by dual-energy x-ray absorptiometry and anthropometry at 2-3 weeks of age. Birth outcome data for mother and infant will be collected. To determine the metabolic response to the study diet, 25 women from each of the two diet groups will be assigned to a metabolic subsample for measuring rates of hepatic glucose production and lipolysis at 34 weeks.
|United States, California|
|San Francisco General Hospital|
|San Francisco, California, United States, 94110|