Comparison of the effects of cows' milk, fortified soy milk, and calcium supplement on weight and fat loss in premenopausal overweight and obese women

Abstract

Background and aims: Recent studies suggest that calcium metabolism and perhaps other components of dairy products may contribute to shifting the energy balance and thus play a role in weight regulation. We compared the effects of cows' milk, calcium fortified soy milk and calcium supplement on weight and body fat reduction in premenopausal overweight and obese women.

Methods and results: In this clinical trial, 100 healthy overweight or obese premenopausal women were randomized to one of the following dietary regimens for 8 weeks: (1) a control diet providing a 500kcal/day deficit, with 500-600mg/day dietary calcium; (2) a calcium-supplemented diet identical to the control diet with 800mg/day of calcium as calcium carbonate; (3) a milk diet providing a 500kcal/day deficit and containing three servings of low-fat milk; (4) a soy milk diet providing a 500kcal/day deficit and containing three servings of calcium fortified soy milk. At baseline and after 8 weeks, weight, waist circumference, and hip circumference were measured. Three 24-h dietary records and physical activity records were also taken. Comparing the mean differences in weight, waist circumference, body mass index (BMI) and waist-to-hip ratio (WHR) using repeated measure of variance analysis showed that changes in waist circumference and WHR were significant among the four groups (p=0.029 and p=0.015, respectively). After adjustment for baseline values, changes in weight and BMI were also significant (p=0.017 and p=0.019, respectively). Weight reductions in high milk, soy milk, calcium supplement and control groups were 4.43±1.93(kg), 3.46±1.28(kg), 3.89±2.40(kg) and 2.87±1.55(kg), respectively. The greatest changes were seen in the high dairy group in all variables.

Conclusion: Increasing low fat milk consumption significantly reduces the general and central obesity beyond a low calorie diet.