Harris R B, Martin R J
J Nutr. 1984 Jun;114(6):1143-50. doi: 10.1093/jn/114.6.1143.
In this study we determined the time course of changes in body composition and of serum concentrations of some hormones in mature rats returning to "set point" following weight loss. Groups of six female rats were fed ad libitum for 10 days. Carcass composition of one group was determined. A control group continued to eat ad libitum. The others were restricted to 5 g per rat per day for 22 days. Carcass composition of groups of rats was determined after 0, 2, 6, 13 and 20 days of refeeding. Of 60 g of body weight lost during restriction, 21 g were fat and 12 g were protein. The fat was replaced by the sixth day of refeeding. Protein and body weight were recovered by the thirteenth day. Calculated efficiency of energy retention was increased until body fat was replete. This was not due to a decrease in metabolism of brown fat, measured in vitro. Serum thyroxine (T4), L-3,3',5'-triiodothyronine (rT3), insulin, corticosterone and free fatty acids did not change with body composition. T3 (L-3,3',5-triiodothyronine) decreased in restricted rats and returned to control levels when body weight, protein and food intake had been restored. These results do not support the concept that body weight is controlled by regulating body fat content.
在本研究中，我们测定了体重减轻后恢复到“设定点”的成年大鼠身体组成变化及某些激素血清浓度的时间进程。将六只雌性大鼠分为一组，随意进食10天。测定其中一组的胴体组成。一个对照组继续随意进食。其他组大鼠每天限制进食5克，持续22天。在重新喂食0、2、6、13和20天后，测定大鼠组的胴体组成。在限制进食期间体重减轻的60克中，21克是脂肪，12克是蛋白质。脂肪在重新喂食的第六天被补充。蛋白质和体重在第十三天恢复。计算出的能量保留效率一直增加，直到身体脂肪充足。这并非由于体外测量的棕色脂肪代谢降低所致。血清甲状腺素（T4）、反三碘甲状腺原氨酸（rT3）、胰岛素、皮质酮和游离脂肪酸并未随身体组成而变化。限制进食的大鼠中三碘甲状腺原氨酸（T3）降低，当体重、蛋白质和食物摄入量恢复后，T3恢复到对照水平。这些结果并不支持体重由调节身体脂肪含量来控制这一概念。
