Thermic & Lipemic Properties of Dietary Carbohydrates (FL33)

The purpose of this study is to determine if consumption of meals containing carbohydrates with different glycemic index (a high glycemic index meal and a low glycemic index meal)have different effects on energy expenditure, type of metabolic fuels used for energy, blood lipids and lipoproteins, and sensations of hunger, fullness, and the hormones related to satiety.

Study Overview

• Status: Completed
• Conditions: Dietary Modification; Exogenous Obesity
• Intervention / Treatment: Other: High Glycemic Index meals; Other: Low Glycemic Index meals

Detailed Description

Little is known about the metabolic effects of chronic dieting and weight cycling in humans, but limited evidence suggests that fatty acid oxidation may be depressed leading to periodic elevation of circulating lipids associated with meal ingestion and preferential storage of fat in adipose tissue. With the traditional approach of restrictive dieting failing to result in permanent weight loss and, possibly producing abnormalities in lipid metabolism, it is important to evaluate alternative approaches to achieve a healthy body weight through improved metabolism. In this study the investigators will test the postprandial metabolic effects of standard mixed meals containing carbohydrates with high glycemic index and compare these effects to responses obtained with standard mixed meals, matched for protein and fat content but containing carbohydrates with low glycemic index.

• Study Type: Interventional
• Enrollment (Actual): 28
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Davis, California, United States, 95616
      • Western Human Nutrition Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 48 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Body mass index between 25 and 30 kg/m2
• Having regular menses
• Willing to refrain from restrictive dieting during the course of the study

Exclusion Criteria:

• Pregnant or currently planning a pregnancy
• Cigarette smoking
• Taking medications to induce weight loss or change appetite
• History of cardiovascular disease
• History of metabolic disorders, including diabetes

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High Glycemic Index meals; Three days of run-in diet with meals containing high glycemic index carbohydrates followed by test day with breakfast meal containing high glycemic index carbohydrates.	Other: High Glycemic Index meals; Dietary intervention with meals containing high glycemic index carbohydrates. All foods provided to meet the individual's energy needs. Standardized test meal (breakfast)also contained only high glycemic index carbohydrates and energy content was adjusted for each individual, providing 40% of daily energy needs.; Other Names: Low Fiber Meals
Experimental: Low Glycemic Index meals; Three days of run-in diet with meals containing low glycemic index carbohydrates followed by test day with breakfast meal containing low glycemic index carbohydrates.	Other: Low Glycemic Index meals; Dietary intervention with meals containing low glycemic index carbohydrates. All foods provided to meet the individual's energy needs. Standardized test meal (breakfast)also contained only low glycemic index carbohydrates and energy content was adjusted for each individual, providing 40% of daily energy needs.; Other Names: High fiber meals

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Respiratory Gas Exchange	Respiratory Gas Exchange will be measured using an automated metabolic cart. Gas analyzers and volumeter will be calibrated using manufacturer's procedures.	30 minutes before a standardized test meal and intermittently for 480 minutes following the meal.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma glucose	1 fasting blood sample (0 minutes) and 9 post-prandial blood samples taken at 30, 60, 90, 120, 150, 210, 270, 360 and 480 minutes following consumption of standardized test meal.	10 blood samples taken over a 480 minute period.
Circulating lipoproteins	Blood samples for lipoprotein analyses were taken at fasting (0 minute) and at 150, 210, and 480 minutes following consumption of test meal. A subset of 10 randomly-selected subjects was chosen for this outcome measure	4 blood samples taken over a 480 minute period
Subjective evaluation of appetite	Visual analog scales were used to assess appetite-related sensations. Four responses were obtained during the fasting phase (120 minutes) and 12 responses were obtained in the 480 minute postprandial period.	16 timepoints measured over 600 minutes
Food consumption at a buffet-style meal	The amount and types of foods consumed were measured after subject was presented with a buffet-style meal.	at 480 minutes following test meal
Body composition	Body composition (fat mass, % fat, lean mass, bone density) will be measured using dual energy x-ray absorptiometry.	measured the morning of the standard meal challenge
Serum insulin	1 fasting blood sample (0 minutes) and 9 post-prandial blood samples taken at 30, 60, 90, 120, 150, 210, 270, 360 and 480 minutes following consumption of test meal.	10 blood samples taken over a 480 minute time period
Plasma leptin	1 fasting blood sample (0 minutes) and 9 post-prandial blood samples taken at 30, 60, 90, 120, 150, 210, 270, 360 and 480 minutes following consumption of test meal.	10 blood samples taken over a 480 minute period
Plasma ghrelin	1 fasting blood sample (0 minutes) and 9 post-prandial blood samples taken at 30, 60, 90, 120, 150, 210, 270, 360 and 480 minutes following consumption of test meal.	10 blood samples taken over a 480 minute time period
Cholecystokinin (CCK)	1 fasting blood sample (0 minutes) and 9 post-prandial blood samples taken at 30, 60, 90, 120, 150, 210, 270, 360 and 480 minutes following consumption of test meal.	10 blood samples taken over a 480 minute time period
GLP-1	1 fasting blood sample (0 minutes) and 9 post-prandial blood samples taken at 30, 60, 90, 120, 150, 210, 270, 360 and 480 minutes following consumption of test meal.	10 blood samples taken over a 480 minute time period

Collaborators and Investigators

• Sponsor: USDA, Western Human Nutrition Research Center
• Investigators: Principal Investigator: Nancy L Keim, PhD, USDA, ARS, WHNRC

Publications and helpful links

General Publications

• Motton DD, Keim NL, Tenorio FA, Horn WF, Rutledge JC. Postprandial monocyte activation in response to meals with high and low glycemic loads in overweight women. Am J Clin Nutr. 2007 Jan;85(1):60-5. doi: 10.1093/ajcn/85.1.60.
• Burton-Freeman BM, Keim NL. Glycemic index, cholecystokinin, satiety and disinhibition: is there an unappreciated paradox for overweight women? Int J Obes (Lond). 2008 Nov;32(11):1647-54. doi: 10.1038/ijo.2008.159. Epub 2008 Sep 30.

Study record dates

Study Major Dates

• Study Start: October 1, 2002
• Primary Completion (Actual): June 1, 2005
• Study Completion (Actual): June 1, 2005

Study Registration Dates

• First Submitted: August 13, 2010
• First Submitted That Met QC Criteria: May 16, 2011
• First Posted (Estimate): May 17, 2011

Study Record Updates

• Last Update Posted (Estimate): July 13, 2011
• Last Update Submitted That Met QC Criteria: July 12, 2011
• Last Verified: July 1, 2011

More Information

Terms related to this study

• Keywords: insulin; lipids; lipoproteins; satiety; energy metabolism; glycemic load
• Other Study ID Numbers: 200210295; FL33 (Other Identifier: USDA-ARS-WHNRC)