The purpose of this study was to determine the existence of sex differences following a 40% caloric restrictive diet and its impact on tibial bone mineral density (BMD) and bone strength between male and female rats. Thirty-two, six-week old Sprague Dawley rats (16 males and 16 females) were randomly divided into an ad libitum fed control group (MC, n=8 and FC, n=8) and a pair fed diet group placed on the 40% caloric restriction (MD, n=8 and FD, n=8) for a 6 week period. The caloric restrictive diet was equivalent to the normal fed diet in vitamin and mineral content where the only difference was 40% less calories. After 6 weeks, there were no significant interaction effects, therefore main effects (i.e., sex and diet) were examined. While the tibial BMD was equivalent between males (0.206 ± 0.003 g/cm2) and females (0.207 ± 0.004 g/cm2), bone strength (amount of force required to break the tibia expressed in Newtons, N) was significantly greater for males (112.0 ± 2.4 N) compared to females (74.8 ± 3.1 N). The BMD was significantly lower for caloric restrictive fed groups (0.200 ± 0.003 g/cm2) compared to normal fed animals (0.213 ± 0.003 g/cm2). In like manner, bone strength significantly lower for diet fed animals (86.5 ± 5.6 N) compared to control fed animals (100.3 ± 5.1N). The results indicate that caloric restriction lowers BMD and bone strength irrespective of sex. However, bone strength was greater for males compared to females.
Folta, Haley, "The Effects of a Caloric Restrictive Diet on Bone Mineral Density and Bone Strength in Male and Female Rats" (2015). Student Research Day Abstracts and Posters. 136.