title: Protein selection by rats adapted to high or moderately low levels of dietary protein.
abstract: After preliminary studies on flavor acceptability, patterns and indices of subsequent feeding behavior were monitored by computer in young rats which were adapted to 15% or 70% casein diets before being offered, sequentially, choices between flavored diet pairs in which the proportions of percentage casein were 5/65, 5/55, 5/45, 5/35 and 5/25. Similarly adapted rats received these choices in the reverse sequence. Rats adapted to 15% casein usually ate randomly from the diet pairs and selected approximately 15-30% casein; individual behaviors were prominent. The 70% casein groups avoided the higher casein diet, often within minutes (except for the first-offered 5/25 choice), and seldom selected more than 10% casein; individual differences were infrequent. Such rats also distinguished between flavored 70% and 65% casein diets. Sizes and numbers of meals and rates of eating differed for the paired diets, especially for rats adapted to 70% casein. A flavor added to the 70% casein adaptation diet was not avoided when present only in the 5% casein diet of a 5/65 choice. Rats adapted to 70% soy protein before receiving flavored 5/65 to 5/25 choices selected 20-28% soy protein, a level far above those of casein selections by rats adapted to 70% casein. Dietary adaptation and type of protein thus affect subsequent diet selection and feeding patterns and indices.
authors.affiliation: Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin-Madison 53706.
authors.forename: J K
authors.initials: JK
authors.lastname: Tews
authors.forename: J J
authors.initials: JJ
authors.lastname: Repa
authors.forename: A E
authors.initials: AE
authors.lastname: Harper
mesh_terms: D000596:Amino Acids / Q000097:blood; D000818:Animals; D001835:Body Weight / Q000502:physiology; D004044:Dietary Proteins / Q000008:administration & dosage*; D005247:Feeding Behavior / Q000502:physiology*; D005518:Food Preferences / Q000502:physiology*; D008297:Male; D009751:Nutritional Requirements; D051381:Rats; D011919:Rats, Inbred Strains; D013649:Taste / Q000502:physiology*
chemical_list: D000596:Amino Acids; D004044:Dietary Proteins