Cleary M P
J Nutr. 1986 Aug;116(8):1489-99. doi: 10.1093/jn/116.8.1489.
Previously, it was found that lean and obese Zucker rats (9-15 wk of age) responded differently to the first of four cycles of food restriction/refeeding. In later cycles, they responded similarly. The present study was undertaken to determine if this finding was due to age, adaptation to the intervention or the obesity. Adult (35-wk-old) lean and obese rats were classified into four groups, ad libitum-fed lean and obese and food-restricted lean and obese. Food-restricted rats underwent four 3-wk periods when they were fed 50% of their ad libitum intake, each followed by a 3-wk period of ad libitum refeeding. Food-restricted rats lost and regained sufficient weight in each cycle to weigh a similar amount as their ad libitum-fed groups by the end of each refeeding period. In lean rats, there were no permanent effects of this intervention except for a 25% reduction in carbohydrate intake. Similar results were found in obese rats, although they did have significantly lower retroperitoneal fat pad weight and serum triacylglycerol levels than ad libitum-fed obese rats at the end of the experiment. These results indicate that lean and obese adult rats respond to each food restriction/refeeding cycle in a similar manner. Results in the earlier experiment would appear to be due both to age and genotype.
此前发现，瘦型和肥胖型 Zucker 大鼠（9 - 15 周龄）对四个食物限制/再喂养周期中的第一个周期反应不同。在后续周期中，它们的反应相似。本研究旨在确定这一发现是由于年龄、对干预的适应还是肥胖所致。将成年（35 周龄）瘦型和肥胖型大鼠分为四组，即自由进食的瘦型和肥胖型以及食物限制的瘦型和肥胖型。食物限制组的大鼠经历四个为期 3 周的阶段，在此期间给予它们自由摄入量 50%的食物，每个阶段之后是为期 3 周的自由再喂养阶段。食物限制组的大鼠在每个周期中体重下降然后恢复，到每个再喂养阶段结束时，体重与自由进食组相似。在瘦型大鼠中，除了碳水化合物摄入量减少 25%外，这种干预没有产生永久性影响。在肥胖型大鼠中也发现了类似结果，尽管在实验结束时，它们的腹膜后脂肪垫重量和血清三酰甘油水平明显低于自由进食的肥胖型大鼠。这些结果表明，成年瘦型和肥胖型大鼠对每个食物限制/再喂养周期的反应相似。早期实验的结果似乎是由年龄和基因型共同导致的。
