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Abstract

Grant Number: 5R21AT002753-02
Project Title: Energy and Appetite Regulation by High and Low CHO Diets
PI Information:NameEmailTitle
STADLER, DIANE D. stadlerd@ohsu.edu

Abstract: DESCRIPTION (provided by applicant): The rising epidemic of obesity in the United States is accompanied by widespread public use of low carbohydrate diets for weight loss. The popularity of these diets is due partly to the promise of a "metabolic advantage" that promotes faster weight loss without an overriding sense of hunger. If this claim is true, we hypothesize that a low-carbohydrate diet will impact hormones and other factors that regulate appetite and energy balance, and result in lower energy intake and greater weight loss, than a high complex carbohydrate diet. To test this hypothesis, we will conduct a randomized, controlled feeding trial in which obese adults will be randomly assigned to one of three interventions: a low-carbohydrate-ad libitum diet, a high-carbohydrate -ad libitum diet, or a high-carbohydrate-energy-restricted diet. The low-carbohydrate diet will be modeled after the Induction Phase of the Atkins Diet. The high carbohydrate diet will be based on the "Dietary Approaches to Stop Hypertension (DASH)" diet. Participants will eat a standardized weight maintenance diet for 3 weeks. Then, for 6-weeks, participants assigned to either ad libitum group will be given their assigned diet at 120% of there estimated energy needs to maintain weight and allowed to eat as much as desired. Participants assigned to the energy-restricted group will be provided a DASH diet at 67% of their estimated energy needs to maintain weight and asked to eat all foods provided. Food intake will be measured daily. Body weight and hunger and satiety scores will be measured three times a week. Body composition and energy expenditure will be measured before and after the intervention. 24-hour profiles of hormones and other factors that influence central appetite and weight regulation (insulin, leptin, ghrelin, PYY, GLP-1) will be measured before, and on first and last days of the intervention, to compare acute and chronic metabolic effects of the diets. The analysis of primary outcomes will be based on repeated measures and longitudinal models methodology. This study offers a unique opportunity to explore how extreme differences in dietary composition, before and after weight loss, affect components of energy balance and markers of central appetite and weight regulation. These results will be used to design hypothesis-driven studies of the identified mediators of appetite and weight regulation in response to dietary manipulation.

Public Health Relevance:
This Public Health Relevance is not available.

Thesaurus Terms:
appetite, bioenergetics, dietary carbohydrate, obesity
body composition, body weight, clinical trial, ghrelin, hunger, incretin hormone, insulin, leptin, neuropeptide Y, nutrient intake activity, satiation, weight control
blood chemistry, clinical research, human subject, nutrition related tag, patient oriented research, questionnaire, urinalysis

Institution: OREGON HEALTH AND SCIENCE UNIVERSITY
3181 SW Sam Jackson Pk Rd
PORTLAND, OR 972393098
Fiscal Year: 2006
Department: MEDICINE
Project Start: 30-SEP-2005
Project End: 31-AUG-2009
ICD: NATIONAL CENTER FOR COMPLEMENTARY & ALTERNATIVE MEDICINE
IRG: ZAT1


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