title: Effects of soy protein supplemented with methionine on blood lipids and adiposity of rats.
abstract: OBJECTIVE
  The effects of soy protein isolate (SPI) versus casein on blood lipids and adiposity were investigated in rats fed methionine-equivalent diets.
  
  
  METHODS
  Twenty-eight male Sprague-Dawley rats (230 to 250 g) were assigned in equal numbers to groups consuming SPI- or casein-based diets (20%) supplemented with L-methionine. After 28 d, blood was collected for triacylglycerol, total cholesterol, and high-density lipoprotein cholesterol assessment and epididymal fat pads were weighed.
  
  
  RESULTS
  Food intake (519 +/- 90 versus 490 +/- 115 g), weight gain (144 +/- 35 versus 133 +/- 28 g), food efficiency ratio (0.29 +/- 0.09 versus 0.28 +/- 0.06), epididymal fat pad weights (5.409 +/- 2.076 versus 4.768 +/- 1.867 g), and serum concentrations of triacylglycerol (96.3 +/- 41.8 versus 93.4 +/- 37.4 mg/dL) and high-density lipoprotein cholesterol (32.6 +/- 7.4 versus 33.8 +/- 4.4 mg/dL) were similar between the casein and SPI groups, respectively. However, total cholesterol (73.8 +/- 17.8 versus 59.3 +/- 11.9 mg/dL) concentration was higher for the casein-fed rats than for the SPI-fed rats, respectively (P < 0.05).
  
  
  CONCLUSIONS
  These results suggest that methionine supplementation may eliminate the decreased fat deposition previously ascribed to soy protein; however, methionine did not abolish the commonly observed hypocholesterolemic effects of soy.
authors.affiliation: Department of Exercise and Nutritional Sciences, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-7251, USA. kern@mail.sdsu.edu
authors.forename: Mark
authors.initials: M
authors.lastname: Kern
authors.forename: Danielle
authors.initials: D
authors.lastname: Ellison
authors.forename: Yessenia
authors.initials: Y
authors.lastname: Marroquin
authors.forename: Marie
authors.initials: M
authors.lastname: Ambrose
authors.forename: Kelly
authors.initials: K
authors.lastname: Mosier
mesh_terms: D000273:Adipose Tissue; D000818:Animals; D001823:Body Composition; D002364:Caseins / Q000008:administration & dosage / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D004044:Dietary Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D004435:Eating; D004822:Epididymis; D008055:Lipids / Q000097:blood*; D008297:Male; D008715:Methionine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D030262:Soybean Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D014280:Triglycerides / Q000097:blood; D015430:Weight Gain
chemical_list: D002364:Caseins; D008076:Cholesterol, HDL; D004044:Dietary Proteins; D008055:Lipids; D030262:Soybean Proteins; D014280:Triglycerides; D002784:Cholesterol; D008715:Methionine