Physiological response of mature rats to replacement of dietary fat with a fat substitute.
The effects of replacing dietary fat with a fat substitute on food intake, body composition and lipid metabolism were examined in rats. Female Sprague-Dawley rats (250 g) were fed diets containing between 2 and 63% of energy as fat for 64 d. Inclusion of a substitute resulted in diets of different fat content but similar texture. When 10% corn oil (21% kJ-fat diet) was replaced with the substitute supplemented with linoleic acid (2% kJ-fat diet), rats increased food intake so that there was no effect on energy intake, body weight, body composition or serum lipid profile. Rats fed a diet containing 10% corn oil and 30% Crisco vegetable shortening (63% kJ-fat diet) became obese and hyperinsulinemic. When half (51% kJ-fat diet) or all (30% kJ-fat diet) of the Crisco was replaced with the fat substitute, the rats increased food intake and were fatter than controls but less obese than rats fed the 63% kJ-fat diet. Hepatic lipid oxidation and ketone synthesis were proportional to the percentage of dietary energy as fat. Adipocyte de novo lipid synthesis was inhibited by 51% kJ-fat and 63% kJ-fat diets. Partial or total replacement of Crisco prevented the hyperinsulinemia observed in 63% kJ-fat rats, suggesting a protective effect against the development of insulin resistance with diet-induced obesity.
Harris
R B
RB
Nutrition Department, Kraft General Foods, Inc., Glenview, IL 60025.
Jones
W K
WK
D000818:Animals; D001786:Blood Glucose; D001823:Body Composition / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D002149:Energy Intake; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D005526:Food, Formulated; D006003:Glycogen / Q000378:metabolism; D007328:Insulin / Q000097:blood; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D001786:Blood Glucose; D004041:Dietary Fats; D005227:Fatty Acids; D007328:Insulin; D006003:Glycogen