title: Effect of soy protein isolate preload on postprandial glycemic control in healthy humans.
abstract: OBJECTIVE
  Premeal consumption of whey protein improves the postmeal glycemic profile, but little information exists on soy protein. The study aim was to examine the effect of consuming different amounts of a soy protein isolate (SPI) before a 75-g oral glucose tolerance test (OGTT) on subsequent glycemic control.
  
  
  METHODS
  After overnight fasting, eight healthy young subjects consumed a 400-mL liquid meal containing 0 g (SP0), 20 g (SP20) or 40 g (SP40) SPI. Thirty minutes after SPI consumption, an OGTT was performed to evaluate the individual glycemic response. Blood glucose and plasma insulin concentrations were measured immediately before the SPI preload (i.e., 30 min before the start of the OGTT) and before (-10 min) and during the OGTT (15, 30, 45, 60, 90, and 120 min).
  
  
  RESULTS
  The incremental area under the curve and peak blood glucose response were significantly less for SP40 than those for SP0 and SP20. Insulin secretion was significantly higher for SP20 and SP40 than that for SP0 before and at 15 min after oral glucose consumption. The incremental area under the curve of plasma insulin was significantly higher for SP20 and SP40 than that for SP0.
  
  
  CONCLUSIONS
  An SPI preload of 40 g, but not 20 g, improved glycemic control in young healthy subjects. Glycemic control appears to be attributed not only to the exaggerated insulin response to SPI preload, but also to non-insulin dependent mechanism(s), such as delayed gastric emptying.
authors.affiliation: Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima, Hiroshima, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kashima
authors.affiliation: Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima, Hiroshima, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Uemoto
authors.affiliation: Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima, Hiroshima, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Eguchi
authors.affiliation: Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima, Hiroshima, Japan.
authors.forename: Masako Yamaoka
authors.initials: MY
authors.lastname: Endo
authors.affiliation: Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima, Hiroshima, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Miura
authors.affiliation: Department of Health Promotion and Development, Graduate School of Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima, Hiroshima, Japan. Electronic address: Fukuba@pu-hiroshima.ac.jp.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Fukuba
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005951:Glucose Tolerance Test / Q000706:statistics & numerical data; D006801:Humans; D007328:Insulin / Q000097:blood; D007564:Japan; D008297:Male; D019518:Postprandial Period / Q000187:drug effects*; D012016:Reference Values; D030262:Soybean Proteins / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin; D030262:Soybean Proteins
keywords: Dose-response; Glucose; Insulin; Oral glucose tolerance test; Soy protein isolate