Moderate caloric restriction improved body composition and maintains bone quality of rats under hypoestrogenism

Hypoestrogenism state is associated with weight and adiposity gain, generally impairing bone properties. Caloric restriction (CR) is the main intervention to promote weight loss, however, a chronic severe restriction can lead to bone loss and malnutrition.

To analyse whether 12 weeks of moderate CR could reduce body mass and adiposity without worsening the bone health of ovariectomized (OVX) rats.

CR and OVX-CR animals were subject daily to receive a 20 % less amount of food based on the last week's consumption of C and OVX groups. Body mass and food intake were recorded weekly, and spontaneous physical activity (SPA) biweekly. The adipose tissue of subcutaneous (SAT), peritoneal (PTAT), and perigonadal (PGAT) portions was collected to record its mass, and the right femur was collected to determine bone volume (BV), density (BD), mineral density (BMD), and percentage of mineral material (MM).

Ovariectomy increased body mass and food intake (p < 0.001), SAT, PTAT, and PGAT mass (p < 0.01), decreased BV (p < 0.05), BD and BMD (p < 0.01) and MM (p < 0.05), but not affected SPA (p = 0.16). CR decreased body mass, SAT, PTAT, and PGAT mass (p < 0.01) and BMD and MM (p < 0.05), but did not affect BV (p = 0.90), BD (p = 0.24), and SPA (p = 0.25). Therefore, post-hoc data did not demonstrate significant differences in these bone parameters between the OVX and OVX-RC groups (p > 0.05).

12 weeks of 20 % of CR is enough to prevent weight and fat gain in the hypoestrogenism state without causing additional worsening in bone properties.