Effect of a daily supplement of soy protein on body composition and insulin secretion in postmenopausal women.
OBJECTIVE
To determine whether a supplement of soy protein improves body composition, body fat distribution, and glucose and insulin metabolism in postmenopausal women without diabetes compared with an isocaloric casein placebo.


METHODS
Randomized, double-blind, placebo-controlled 3-month trial.


METHODS
Clinical Research Center.


METHODS
Fifteen postmenopausal women.


METHODS
Computed tomographic scans at L4/L5, dual energy x-ray absorptiometry, hyperglycemic clamps.


METHODS
Total fat, total abdominal fat, visceral fat, subcutaneous abdominal fat, and insulin secretion.


RESULTS
Weight by dual energy x-ray absorptiometry did not change between groups (+1.38 +/- 2.02 kg for placebo vs. +0.756 +/- 1.32 kg for soy, mean +/- SD). Total and subcutaneous abdominal fat increased more in the placebo group than in the soy group (for differences between groups in total abdominal fat: +38.62 +/- 22.84 cm(2) for placebo vs. -11.86 +/- 31.48 cm(2) for soy; subcutaneous abdominal fat: +22.91 +/- 28.58 cm(2) for placebo vs. -14.73 +/- 22.26 cm(2) for soy). Insulin secretion, visceral fat, total body fat, and lean mass did not differ between groups. Isoflavone levels increased more in the soy group.


CONCLUSIONS
A daily supplement of soy protein prevents the increase in subcutaneous and total abdominal fat observed with an isocaloric casein placebo in postmenopausal women.
Sites
Cynthia K
CK
Department of Obstetrics and Gynecology and Pharmacology, University of Alabama at Birmingham, Birmingham, Alabama 35249, USA. csites@uab.edu
Cooper
Brian C
BC
Toth
Michael J
MJ
Gastaldelli
Amalia
A
Arabshahi
Ali
A
Barnes
Stephen
S
D050153:Abdominal Fat / Q000187:drug effects; D001786:Blood Glucose / Q000032:analysis / Q000187:drug effects; D001823:Body Composition / Q000187:drug effects*; D019587:Dietary Supplements; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050152:Intra-Abdominal Fat / Q000187:drug effects; D007529:Isoflavones / Q000097:blood; D008875:Middle Aged; D010919:Placebos; D017698:Postmenopause / Q000097:blood / Q000187:drug effects* / Q000378:metabolism; D030262:Soybean Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D014057:Tomography, X-Ray Computed
D001786:Blood Glucose; D007328:Insulin; D007529:Isoflavones; D010919:Placebos; D030262:Soybean Proteins