Supplementation with soy-protein-rich foods does not enhance weight loss.
The objective of this study was to determine whether a weight-loss diet high in soy-protein-rich foods leads to greater weight loss and reductions in waist circumference, fat mass, and cardiovascular disease risk factors than a control diet. Groups of overweight women (body mass index [calculated as kg/m(2)] of 28 to 33, aged 25 to 49 years) were counseled to decrease their caloric intake by 500 kcal/day for a period of 12 weeks; in addition, the soy-protein-rich group was counseled to consume 15 g soy protein/1,000 kcal daily. Soy-protein-rich foods were provided to subjects. Body weight, waist circumference, percent body fat, fat-free mass, lipids, glucose, and insulin were measured at repeated intervals. Forty-seven women completed the study. Both groups lost a similar amount of weight both when a completers only (-3.18%+/-0.63% vs -4.04%+/-0.95% for soy-protein-rich and control diets, respectively) and a last-observation-carried-forward analysis (-1.93%+/-0.50% vs -2.50%+/-0.67%, for soy-protein-rich and control diets, respectively) were performed. There was no difference between groups in change in percent fat mass (-5.31%+/-1.50% for soy-protein-rich diet vs -3.94%+/-1.68% for control diet), percent fat-free mass, and waist circumference. There was no dietary assignment-by-group interaction on lipid, glucose, and insulin concentrations when analyses were done on completers only or on all subjects using a last-observation-carried-forward approach. Percent change in any of the biochemical parameters studied over the 12-week period was not significantly different between groups. Our results do not lend support to the emerging notion that soy-protein-rich foods could be considered potential functional foods for weight management, in the quantities consumed in this study.
St-Onge
Marie-Pierre
MP
New York Obesity Research Center, St Luke's/Roosevelt Hospital, New York, NY 10026, USA. ms2554@columbia.edu
Claps
Nancy
N
Wolper
Carla
C
Heymsfield
Steven B
SB
D000328:Adult; D000704:Analysis of Variance; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition / Q000187:drug effects* / Q000502:physiology; D015992:Body Mass Index; D004038:Diet, Reducing; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy*; D030262:Soybean Proteins / Q000008:administration & dosage*; D016896:Treatment Outcome; D049629:Waist-Hip Ratio; D015431:Weight Loss / Q000187:drug effects / Q000502:physiology
D001786:Blood Glucose; D007328:Insulin; D008055:Lipids; D030262:Soybean Proteins