Consequences of high‐fat diets on body growth and bone mineral density, in growing rats

Abstract

Objective: To investigate in growing rats, the effect of high‐fat diets with different n‐6/n‐3 fatty acids ratios, on body growth and parameters of bone densitometry. Weaning male Wistar rats (n=50) were fed ad libitum one of the following diets for 8 wk: control (C; fat=7% w/w) (AIN‐93G) or a high‐fat diet (20% w/w): soybean oil (SO), corn‐oil (CO), linseed oil (LO) or beef‐tallow (BT). Body weights (W) and lengths (L) were recorded every 4 days. W and L gain velocities were calculated (g W/100g W rat and L/10cm L rat, respectively). After 8 wk, rats were sacrificed. Total skeleton bone mineral density (BMD) and bone mineral content (BMC) were evaluated by DXA using a Lunar DPX‐L. Spine BMD was determined. Groups were analyzed as: a) BT vs. SO, CO and LO; b) SO, CO and LO; c) C vs. SO.Results: a) BT achieved the lowest W, total skeleton BMC, BMC/W and spine BMD (P<0.0001); b) No significant differences were observed on anthropometric measurements, total skeleton BMC, BMD, BMC/W or spine BMD, but spine BMD on SO showed a tendency to a diminution (P=0.064); c) Anthropometric measurements, total skeleton BMC and BMD were similar but SO showed reductions of 10% on total BMC/W and spine BMD.Conclusion: The combination of adequate amounts of dietary fat and n‐6/n‐3 fatty acids ratio protects bone health and maintains body growth. Awarded by UBACyT O 003‐4.