High fat-sucrose diet effects on femoral neck geometry and biomechanics.

Diets high in fat and sucrose may affect calcium metabolism, by decreasing calcium absorption in the gastrointestinal tract and decreasing calcium reabsorption in distal renal tubules, but information about the effects of high fat-sucrose diet on immature-bone material and structural properties is lacking. The present study examined the effects of a high fat-sucrose diet on the geometrical and biomechanical properties of the femoral neck in rapidly-growing rats. Sprague-Dawley female rats were assigned randomly to a high fat-sucrose diet group or a control-diet group for 10 weeks. Cantilever-bending tests to failure were conducted, and geometrical and material properties were calculated from fracture-surface cross-sections and were correlated with mechanical data. Geometrically, the high fat-sucrose diet decreased the relative size of the femoral neck cortical shell and increased the trabecular core. The femoral necks of rats fed the high fat-sucrose diet had signiflcanctly lower structural rigidity, load at proportional limit, maximum load, energy at proportional limit, total energy, normal stress at proportional limit and maximum normal stress than the controls.