title: Dietary whey protein decreases food intake and body fat in rats.
abstract: We investigated the effects of dietary whey protein on food intake, body fat, and body weight gain in rats. Adult (11-12 week) male Sprague-Dawley rats were divided into three dietary treatment groups for a 10-week study: control. Whey protein (HP-W), or high-protein content control (HP-S). Albumin was used as the basic protein source for all three diets. HP-W and HP-S diets contained an additional 24% (wt/wt) whey or isoflavone-free soy protein, respectively. Food intake, body weight, body fat, respiratory quotient (RQ), plasma cholecystokinin (CCK), glucagon like peptide-1 (GLP-1), peptide YY (PYY), and leptin were measured during and/or at the end of the study. The results showed that body fat and body weight gain were lower (P < 0.05) at the end of study in rats fed HP-W or HP-S vs. control diet. The cumulative food intake measured over the 10-week study period was lower in the HP-W vs. control and HP-S groups (P < 0.01). Further, HP-W fed rats exhibited lower N(2) free RQ values than did control and HP-S groups (P < 0.01). Plasma concentrations of total GLP-1 were higher in HP-W and HP-S vs. control group (P < 0.05), whereas plasma CCK, PYY, and leptin did not differ among the three groups. In conclusion, although dietary HP-W and HP-S each decrease body fat accumulation and body weight gain, the mechanism(s) involved appear to be different. HP-S fed rats exhibit increased fat oxidation, whereas HP-W fed rats show decreased food intake and increased fat oxidation, which may contribute to the effects of whey protein on body fat.
authors.affiliation: Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA. june.zhou@va.gov
authors.forename: June
authors.initials: J
authors.lastname: Zhou
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Keenan
authors.forename: Jack N
authors.initials: JN
authors.lastname: Losso
authors.forename: Anne M
authors.initials: AM
authors.lastname: Raggio
authors.forename: Li
authors.initials: L
authors.lastname: Shen
authors.forename: Kathleen L
authors.initials: KL
authors.lastname: McCutcheon
authors.forename: Richard T
authors.initials: RT
authors.lastname: Tulley
authors.forename: Marc R
authors.initials: MR
authors.lastname: Blackman
authors.forename: Roy J
authors.initials: RJ
authors.lastname: Martin
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D004044:Dietary Proteins / Q000494:pharmacology*; D002149:Energy Intake / Q000187:drug effects*; D004734:Energy Metabolism / Q000187:drug effects*; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008894:Milk Proteins / Q000494:pharmacology*; D009584:Nitrogen / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D030262:Soybean Proteins / Q000494:pharmacology*; D015430:Weight Gain / Q000187:drug effects*; D000067816:Whey Proteins
chemical_list: D004044:Dietary Proteins; D008894:Milk Proteins; D030262:Soybean Proteins; D000067816:Whey Proteins; D052216:Glucagon-Like Peptide 1; D009584:Nitrogen