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The Breakfast Study (Breakfast)

This study has been completed.
International Life Sciences Institute
Information provided by (Responsible Party):
Temple University Identifier:
First received: January 3, 2008
Last updated: June 28, 2013
Last verified: January 2008
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.

Condition Intervention
Glycemic Response
Other: high GI
Other: Low GI
Other: Low GI Low Carb
Other: High GI Low carb

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: The Effects of Low and High Glycemic Index Foods and Protein on Glycemic Response and Hunger

Further study details as provided by Temple University:

Primary Outcome Measures:
  • To compare the effects of breakfast meals containing low GI and high GI foods on glucose and insulin responses [ Time Frame: post ]

Secondary Outcome Measures:
  • To examine the effects of low and high GI meals on subjective ratings of hunger and subsequent food intake [ Time Frame: 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. [ Time Frame: post ]

Enrollment: 24
Study Start Date: January 2006
Study Completion Date: June 2008
Primary Completion Date: June 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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

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.


Ages Eligible for Study:   21 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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.
  Contacts and Locations
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Please refer to this study by its identifier: NCT00593307

United States, Pennsylvania
Temple University - Center for Obesity Research and Education
Philadelphia, Pennsylvania, United States, 19140
Sponsors and Collaborators
Temple University
International Life Sciences Institute
Principal Investigator: Gary D Foster, PhD Temple University - Center for Obesity Research and Education
  More Information

Responsible Party: Temple University Identifier: NCT00593307     History of Changes
Other Study ID Numbers: 10917
Study First Received: January 3, 2008
Last Updated: June 28, 2013

Keywords provided by Temple University:
glycemic response
hunger processed this record on April 28, 2017