When compared to traditional low-calorie diets, soy-based low-calorie diets are more effective at reducing body weight and fat and improving favorable blood cholesterol measurements.
The effects of a soy-based low-calorie diet on weight control, body composition, and blood lipid profiles (compared with a traditional low-calorie diet) were recently studied. Normally healthy obese adults were randomized to two groups. The soy-based low-calorie group consumed soy protein as the only protein source, and the traditional low-calorie group consumed two-thirds animal protein and the rest plant protein. Both diets contained approximately 1200 calories and were maintained for 8 weeks.
Body weight, body mass index, body fat percentage, and waist circumference decreased significantly in both groups. The decrease in body fat percentage in the soy group was greater than that in the traditional group. Serum total cholesterol concentrations, LDL cholesterol concentrations, and liver function parameters decreased in the soy-based group and were significantly different from measurements in the traditional diet group. No significant change in triglycerides, HDL cholesterol levels, and fasting glucose levels was found either group.
Based on these results, soy-based low-calorie diets can significantly decrease serum total cholesterol and LDL cholesterol concentrations and have a greater effect on reducing body fat percentage than traditional low-calorie diets.
Source: Effectiveness of a soy-based compared with a traditional low-calorie diet on weight loss and lipid levels in overweight adults, Liao et al, Nutrition 2007 Jul-Aug;23(7-8):551-6.
