Clinical trial NCT01354574: Thermic & Lipemic Properties of Dietary Carbohydrates
Official title: Thermic & Lipemic Properties of Dietary Carbohydrates
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Exogenous Obesity
Dietary Modification
Keywords: energy metabolism
lipids
lipoproteins
satiety
glycemic load
insulin
Lead sponsor: USDA, Western Human Nutrition Research Center
Sponsor class: FED
First posted: 2011-05-17
Enrollment: 28
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 48
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: 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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Respiratory Gas Exchange
timeFrame: 30 minutes before a standardized test meal and intermittently for 480 minutes following the meal.
Secondary outcomes:
measure: Plasma glucose
timeFrame: 10 blood samples taken over a 480 minute period.
measure: Circulating lipoproteins
timeFrame: 4 blood samples taken over a 480 minute period
measure: Subjective evaluation of appetite
timeFrame: 16 timepoints measured over 600 minutes
measure: Food consumption at a buffet-style meal
timeFrame: at 480 minutes following test meal
measure: Body composition
timeFrame: measured the morning of the standard meal challenge
measure: Serum insulin
timeFrame: 10 blood samples taken over a 480 minute time period
measure: Plasma leptin
timeFrame: 10 blood samples taken over a 480 minute period
measure: Plasma ghrelin
timeFrame: 10 blood samples taken over a 480 minute time period
measure: Cholecystokinin (CCK)
timeFrame: 10 blood samples taken over a 480 minute time period
measure: GLP-1
timeFrame: 10 blood samples taken over a 480 minute time period
Other outcomes:
Locations:
city: Davis
country: United States
facility: Western Human Nutrition Research Center
state: California
Study officials:
affiliation: USDA, ARS, WHNRC
name: Nancy L Keim, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
citation: 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.