Effects of 16 weeks of isoflavone-rich soy protein on weight and fat gain in female college students

Human intervention trials aimed at reducing weight gain and body fat using soy proteinand isoflavones are few in number and show equivocal results. The objective of this study wasto compare the effects of a daily isoflavone-rich soy-based meal replacement versus a casein-based control on body weight and fat gain over 16 weeks in 18 to 19 year old female collegefreshmen (N = 120). No difference was found between groups with respect to body weight orcomposition measures. There was a significant increase in body weight in both groups over time(p < 0.05), and this increase is 50 to 75% less than previously reported in college freshmen.Both soy and milk-based meal replacements may be beneficial with respect to slowing weightgain in healthy premenopausal women; however, further study is needed to determine the effectsof soy and casein meal replacements using a non-intervention control group.