Early biochemical changes and histological analysis in adipose tissue and liver of rats fed high‐fat diet (HFD) with different fatty acid composition

Abstract

Early metabolic alterations induced by a high content of fat in diet are poorly understood and less is known about if the type of fat play an important role in lipid metabolism, thus we studied rats fed 7 or 21% fat in diet for 21 d. Fat sources were coconut (CO), safflower (SF) or soybean (SB) oil. Our results showed minor significant differences in the biochemical and hormonal variables among groups during fast. Interestingly, rats fed CO had higher serum insulin in fed state resulting in lower serum glucose in comparison to SF and SB and was attenuated with HFD. On the other hand, rats fed HFD showed higher serum free fatty acids (FFA), glycerol and triglycerides during the fed state, independently of the type of dietary fat. In addition, as excepted, rats fed HFD (21%) had lower serum adiponectin. No significant changes were observed for serum cholesterol, leptin and glucagon. These results indicate that in 3 wks, consumption of a HFD produced biochemical abnormalities of carbohydrate and lipid metabolism. Histological analysis showed that rats fed 21% CO have some hepatic fat deposition and larger adipocytes. Thus, consumption of CO increased postprandial insulin release and a HFD increased lipolysis in fed state. These results also showed that previously to body weight changes, metabolic alterations induced by HFD occurred first in the fed state rather than in fast. Supported by Conacyt.