High-fat diets affect energy and bone metabolism in growing rats

MACRI V; GONZALES CHAVES M; MANDALUNIS P,; ZENI S; LIFSHITZ F; FRIEDMAN S

EUROPEAN JOURNAL OF NUTRITION

DR DIETRICH STEINKOPFF VERLAG

Año: 2010 vol. 51 p. 399 - 406

1436-6207

Abstract: Background High-fat diets are usually associated with greater weight (W) gain and body fat (BF) content. However, it is still unclear whether the type and amount of fat consumed influences BF. Additionally, dietary fat intake may have consequences for skeletal health. Objective To evaluate in healthy growing rats, the effects of high-fat diets and type of dietary fat consumed (saturated or vegetable oils), on energy and bone metabolism. Methods At weaning, male Wistar rats (n=50) were fed either a control diet (C; fat=7% w/w) or a highfat diet (20% w/w) containing either: soybean oil (SO), corn-oil (CO), linseed oil (LO) or beef-tallow (BT) for 8 weeks. Zoometric parameters, BF, food intake and digestibility, total and bone alkaline phosphatase (t-AP and b-AP) were recorded. Total skeleton bone mineral density (BMD) and content (BMC), BMC/W, spine BMD (DXA) and bone volume (static-histomorphometry) was assessed. Results Animals fed BT diet achieved lower W versus C. Rats fed high-fat vegetable oil diets showed similar effects on the zoometric but differed in BF. BT showed the lowest lipid digestibility and BMC. In contrast, high-vegetable oil diets produced no significant differences in BMC, BMC/W, BMD, spine BMD and bone volume. Marked differences were observed for LO and BT groups in b-AP and CO and BT groups in bone volume. Conclusion Diets high in saturated fat adversely affect energy and bone metabolisms, in growing healthy male rats. High vegetable oil diets did not produce significant changes in zoometric and bone parameters. Suggested Reviewers: Laura Schreier