Carbohydrate vs. fat intake: evidence for differing patterns of macronutrient selection in two inbred mouse strains. Smith, Brenda K., David B. West, and David A. York. Obesity, Diabetes and Metabolism Section, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA 70808, Department of Physiology, Louisiana State University Medical Center, New Orleans, LA 70112
APStracts 3:0315R, 1996.
As a first step toward developing a mouse model to characterize genetic factors linked to the preferential intake of dietary carbohydrate or fat, we have identified two mouse strains which exhibit distinctly different patterns of macronutrient selection. Macronutrient selection was evaluated in AKR/J and SWR/J mice, two strains that have been characterized previously for their sensitivity to high-fat dietary obesity. Mice were adapted to a self-selection protocol in which separate carbohydrate, fat and protein sources were simultaneously available. AKR/J mice ate 30% more calories than the SWR/J mice. Further, strain comparisons revealed a significantly higher proportion of fat intake by the AKR/J mice (69% vs. 28%), and in the SWR/J mice, a significantly higher intake of carbohydrate (62% vs. 24%). The mice were then returned to a standard chow diet for 10 weeks. These mice subsequently were allowed to self-select from two composite energy diets (carbohydrate and protein, or fat and protein). Once again, AKR/J mice selected a greater proportion of energy from the fat/protein diet (85%) than did the SWR/J strain (32%). These findings suggest a possible relationship between sensitivity to dietary obesity and fat selection.

Received 22 March 1996; accepted in final form 15 July 1996.
APS Manuscript Number R176-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 29 August 1996