Kristin Welter ’07

How Does the Distribution of Body Fat Change in Response to Equivalent Amounts of Dairy Milk vs. Soy Milk in Rats?

Dietary calcium affects weight loss in both humans and laboratory animals.  Calcium from dairy products appears to increase fat loss in the abdominal region.  The purpose of this study was to determine if a diet containing calcium from dairy milk has a different effect on visceral fat in rats than a diet containing calcium from soy milk. 

Methods: Twenty-one, adult (14-16 months old), male Sprague-Dawley rats were randomly assigned to three groups.  A standard diet of 30g rat chow and water was fed to one group as a control.  Dairy milk was incorporated into the diet of another group, while a Calorically equivalent amount of soy milk was added to the diet of the third group.  The amount of rat chow fed to the treatment groups was reduced to 25g so that all three diets contained an equal amount of Calories.  Rats' weights and food intakes were measured over a period of six weeks.  Rats were then euthanized and visceral adipose tissue was removed and weighed.  Averages for each group were calculated and t-tests were performed on the data. 

Results:  On average, all three groups (control, dairy-fed and soy-fed) lost weight over the course of the study.  There was no significant difference in the amount of weight loss of each group.  There was no significant difference in the amount of visceral fat removed from each rat of the control group and the dairy-fed group, the control group and the soy-fed group, and the dairy-fed group and the soy-fed group (p= 0.867; p= 0.335; p= 0.108) respectively.  

Conclusions/Discussion:  Although the results were not statistically significant in demonstrating a relationship between dairy milk or soy milk and visceral fat loss, there appears to be a trend in the difference in the amount of visceral fat between the soy-fed group and the dairy-fed groups; with the soy-fed rats having the least amount of visceral fat and greatest weight loss.  A larger sample size of rats would allow us to study this correlation further.  

Research Advisor: Jayne Byrne, MS, RDN, LD