Effect Of Refeeding After Rapid Or Slow Body Mass Reduction On Body Composition In Rats

Abstract

We showed that protein in the liver (L) and small intestine (SI) decreased in rats after body mass (BM) reduction regardless of BM reduction period (EB 2005). The aim of this study was to investigate the effect of refeeding after rapid or slow BM reduction in rats. Fifteen rats were assigned to a group fed ad-lib throughout the study as a control without BM reduction (C, n=5), moderately restricted energy intake for 21 days to reduce BM slowly (S, n=5) or fasted for the last 3 days of the study to reach comparable BM in S rapidly (R, n=5). After BM reduction, S and R were refed for 12 h and killed 4 h later. C was killed at the same time. Food intake during refeeding was 21.8 (SD 2.8), 27.5 (1.7) and 37.1 (5.1) in C, R and S, respectively. Refeeding regained BM by 5% in R and by 2% in S. BM excluding contents in digestive tracts was 515 g (14), 465 (16) and 455 (19) in C, R and S, respectively. The weight and water did not differ in the stomach (St) and gastrocnemius (G), while they were recovered to C were lower in R than S in L and lower in R and S than C in SI. Protein was C>S>R in L and C>R=S in SI whereas did not differ in St and G. Total lipid was C>R=S in L, SI and G while did not differ in St. Glycogen was S>R>C in L and S=R>C in G while comparable in St and SI. These results suggest that refeeding after BM reduction gained glycogen in L and skeletal muscle dramatically however was not able to recover protein in L and SI without difference in BM reduction mode.