ILSI Human Nutrition Institute (ILSI HNI) sponsors a grants program for supplemental research on the physiologic effects of dietary carbohydrates. The program, implemented in 1994, has provided over $700,000 to investigators around the world who have examined the relationship between carbohydrates and:
- food and energy intake
- substrate metabolism and energy expenditure
- blood lipids and lipoprotein kinetics
- cognitive and physical performance.
“This program has been instrumental in providing important scientific data in understanding the physiologic effects of dietary carbohydrates, in that carbohydrates generally represent over half of total energy intake,” said Dr. Suzanne Harris, executive director, ILSI. “Another critical component of this awards program,” noted Dr. Harris, “is its international scope. The awards are open to investigators in any country and have been granted to five investigators outside the United States.”
Supplemental Research Award--2006 Request for Proposals
The areas of interest in the 2006 RFP are:
appetite control in the context of energy balance,
glycemic response as it relates to risk for overweight/obesity and chronic diseases,
food intake behavior, physical activity patterns and performance, and
gut health.
To view/download the Request for Proposals and application form, click here.The application deadline is October 27, 2006. One award will be made with the announcement of the winner by January 2007.
Research Findings
Of the 15 funded proposals, 12 have been completed, and the findings have resulted in publication of 20 research papers, reviews, and abstracts. (To view a table listing past and current research, click here. Five awards have addressed issues related to food and energy intake. Five awards have addressed substrate oxidation and energy expenditure, five have examined blood lipids and lipoprotein kinetics, and two have assessed physiologic effects of carbohydrates on cognitive and physical performance.
Food and Energy Intake
To assess the issues related to the relationship between the amount and type of carbohydrate consumed and satiety and energy intake, funding was awarded to Dr. Rolls (1994) who demonstrated that energy density is a more important determinant of short-term energy intake than fat content in lean and obese women; Dr. Schneeman (1994) who showed that isocaloric addition of either viscous fiber or fat to a low-fiber, low-fat test meal reduced hunger in women but not post-test meal food intake; Dr. Pelkman (2000) who assessed the effects of a glycemic index and glycemic load on satiety and cardiovascular risk factors; Dr. Bergeron (1997) who showed that weight loss can be achieved during ad libitum consumption of high-carbohydrate diets; and Dr. Havel who found an effect of high fructose intakes on leptin production in humans. The grant awarded to Dr. Nasser in 2003, funds research that will examine the effect of glycemic response to a preload on food reinforcement measured by a novel operant task in which subjects choose between food items or money illustrated on a computer screen.
Substrate Oxidation and Energy Expenditure
To provide answers to questions about the effect of carbohydrate content and composition on substrate oxidation and energy expenditure, funding was awarded to Dr. Roy (1996), who demonstrated that an increased in insoluble fiber intake without an alteration in total energy does not affect energy expenditure, substrate metabolism or other metabolic parameters. Dr. Bergeron (1997), Dr. Parks (1999) and Dr. Sunehag (2000) demonstrated a reduction in fat oxidation with carbohydrate feeding, results that are consistent with other studies. Dr. Schrauwen (2000) examined the role of uncoupling protein 3 in the metabolism of carbohydrate in healthy male subjects and found that carbohydrates are not the primary determinant of mitochondrial energy efficiency.
Blood Lipids and Lipoprotein Kinetics
Five projects have assessed whether the amount and/or type of carbohydrate associated with a low-fat diet influence blood lipid response, the metabolic basis for the response, whether obese or nonobese subjects respond similarly, and if alterations carry the same risk for cardiovascular disease as observed with high-fat Western diets. Dr. Hellerstein (1994) confirmed previous observations that high-carbohydrate diets are accompanied by an increase in blood triglycerides and a decrease in HDL cholesterol. Dr. Bergeron (1997) and Dr. Pelkman (2000), however, demonstrated these changes are altered or avoided when weight loss occurs with high-carbohydrate diets. Dr. Hellerstein and Dr. Parks (1999) both demonstrated that the source of fatty acids in blood lipids is primarily from plasma-free fatty acids recirculating from peripheral adipose tissue with the proportion varying as a function of dietary fat and carbohydrate content, body fat status, and feeding status. Dr. Delzenne (1996) demonstrated high intake of fermentable carbohydrates in animal models may attenuate the predisposing effect of high carbohydrates to increase blood triglycerides in humans. The grant awarded to Dr. Mittendorfer (2002) funds research that investigates the effect of dietary carbohydrate content on lipoproteins kinetics in response to weight loss in abdominally obese men and women.
Cognitive and Physical Performance
Carbohydrate-rich diets are known for providing important metabolic fuel for physical performance, but their effects on cognitive performance are not well known. Research conducted by Dr. Fischer (2001) compared the effects of a carbohydrate-rich, a protein-rich breakfast, and a fat-rich breakfast and found that the macronutrient composition of meals does not affect cognitive performance but that the composition has to differ quite extremely to result in significant differences. Dr. Jeukendrup (2002) is analyzing methods to improve the contribution of ingested carbohydrates to energy expenditure during exercise by using stab le isotopes to study exogenous carbohydrate oxidation in male and female athletes.