The Breakfast Study (Breakfast)

The Effects of Low and High Glycemic Index Foods and Protein on Glycemic Response and Hunger

The overall objective is to investigate the effects of low and high glycemic index (GI) meals varying in protein content on plasma glucose and insulin response, subjective ratings of hunger, and subsequent food intake in twenty healthy, sedentary, overweight and obese men and women between the ages of 21-65.

Study Overview

• Status: Completed
• Conditions: Hunger; Glycemic Response
• Intervention / Treatment: Other: Low GI; Other: Low GI Low Carb; Other: high GI; Other: High GI Low carb

Detailed Description

Each individual will participate separately in four testing sessions. Each testing session will last for approximately 5 hours and will be separated by a minimum of one week. Participants will arrive at the Temple University GCRC or CORE at either 7:30 a.m. or 8:30 a.m. after an overnight fast (10-12 hours) to ensure that all participants are in the same metabolic state. Upon arrival the experimenter will ask participants to complete a pre-session questionnaire and rate their feelings of hunger and satiety on a visual analog scale (VAS). An indwelling catheter will be inserted in an antecubital vein by the study nurse and a baseline blood sample will be obtained for measurement of glucose and insulin concentrations. Glucose will be measured by the glucose oxidase method using a glucose analyzer and insulin will be measured by radioimmunoassay.

One of four isocaloric meals (see example below), varying in macronutrient content and GI value of foods, will be administered in random order at either 8:00 a.m. or 9:00 a.m. Energy density will be controlled. The meal and 8 ounces of water will be consumed within fifteen minutes. A short visual analog questionnaire will be distributed at the conclusion of the meal to rate the meal consumed. Blood samples will be taken 15 minutes after food consumption and at 30 minute intervals (i.e., 30, 60, 90, 120, 150, 180, 210, and 240 minutes) over four hours following administration of the meal. Four milliliters of blood will be collected at each time point (via indwelling catheter), resulting in a total of 40 milliliters of blood collected at each study session and 160 milliliters (i.e., 40 ml x 4 testing sessions) within an 8 week time period. Participants will be asked to rate their feelings of hunger at these time points. Following the last blood sample, participants will be given the opportunity to consume food ad libitum from a buffet style lunch. Based on known serving sizes and measurements of unconsumed food, the amount of food eaten and its associated energy content will be determined.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19140
      • Temple University - Center for Obesity Research and Education

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Men and women between the ages of 21-65 with a BMI of 25-40(kg/m2)

Exclusion Criteria:

• Individuals who are currently dieting or restricting food intake and who report pre-existing health afflictions such as diabetes, use of prescription medications, use of appetite suppressants, or regular tobacco use will be excluded from the study as they may affect appetite or impact the dependent measures of this study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Low GI; low GI breakfast	Other: Low GI; low GI, high carb breakfast
Experimental: Low GI -low carb; Low GI and Low carb breakfast	Other: Low GI Low Carb; low GI low carb breakfast
Experimental: High GI; High GI breakfast	Other: high GI; high GI and high carb breakfast
Experimental: High GI Low Carb; high GI low carb breakfast	Other: High GI Low carb; high GI low carb breakfast

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
To compare the effects of breakfast meals containing low GI and high GI foods on glucose and insulin responses	post

Secondary Outcome Measures

Outcome Measure	Time Frame
To examine the effects of low and high GI meals on subjective ratings of hunger and subsequent food intake	post
To compare the effects of high protein meals containing either low or high GI foods with high carbohydrate meals containing either low or high HI food on glucose and insulin response, subjective ratings of hunger, and subsequent food intake.	post

Collaborators and Investigators

• Sponsor: Temple University
• Collaborators: International Life Sciences Institute

Study record dates

Study Major Dates

• Study Start: January 1, 2006
• Primary Completion (Actual): June 1, 2008
• Study Completion (Actual): June 1, 2008

Study Registration Dates

• First Submitted: January 3, 2008
• First Submitted That Met QC Criteria: January 14, 2008
• First Posted (Estimate): January 15, 2008

Study Record Updates

• Last Update Posted (Estimate): July 1, 2013
• Last Update Submitted That Met QC Criteria: June 28, 2013
• Last Verified: January 1, 2008

More Information

Terms related to this study

• Keywords: hunger; glycemic response
• Other Study ID Numbers: 10917 (Registry Identifier: DAIDS ES); ILSI