Effects of short-term refeeding after rapid or slow body mass reduction on body composition in adult rats

SummaryWe previously observed that digestive tract mass decreased more in rats experiencing rapid body mass (BM) reduction than in those undergoing slow BM reduction. To determine if BM reduction speed influences body composition after refeeding, rats were assigned to three groups. The control group (C) ate ad libitum, the slow group (S) received restricted food for 21 days to slowly reduce BM, and the rapid group (R) ate ad libitum for 18 days and fasted for the last 3 days to rapidly reach a BM comparable to that of S. Water was restricted for R on day 21. After the BM reduction, both R and S were re-fed ad libitum for 12 h and then were sacrificed with C 4-h later. The BM and masses of the carcass, adipose tissue, and small intestine in both R and S did not return to that of C during the 16-h recovery, although no differences were observed between R and S. The liver and stomach mass in both R and S recovered to that of C. The mass and water, protein, total lipid and glycogen content in the skeletal muscle did not differ between R and S. We concluded that body composition after short-term refeeding is not influenced by the speed of BM reduction.