Prats E, Monfar M, Castellà J, Iglesias R, Alemany M
Department de Bioquímica i Fisiologia, Universitat de Barcelona, Spain.
Physiol Behav. 1989 Feb;45(2):263-72. doi: 10.1016/0031-9384(89)90128-5.
The proportion of lipid, carbohydrate and protein energy self-selected by male and female rats from a cafeteria diet has been studied for a 48-day period (36-day in female rats). The diet consisted in 12 different items and was offered daily, in excess and under otherwise standard conditions, to rats--caged in groups of three--from weaning to adulthood. Groups of control animals were studied in parallel and compared with the cafeteria groups. Cafeteria diet fed groups of rats ingested more energy and lowered their metabolic efficiency with age. Male rats ate more than females and increased their body weight even after female practically stopped growing. There was a wide variation in the aliments consumed each day by the cafeteria-fed rats. However, the proportion of lipid, protein and carbohydrate the rats ate remained constant. Male rats ingested more lipid than females. Carbohydrate consumption was constant in control and cafeteria fed groups of rats independently of sex. Protein consumption was higher in cafeteria rats than in controls, but the differences were not so important as with liquid. Fiber content of the cafeteria diet was lower than that of the control diet. The cafeteria diet selected by the rats was, thus, hypercaloric and hyperlipidic, with practically the same amount of carbohydrate than the control diet, slightly hyperproteic and, nevertheless, remarkably constant in its composition with respect to time. Cafeteria rats had a higher water intake than controls. All these trends were maintained despite the observed changes in the animals' tastes and their differential consumption of the ailments of the diet.
在48天的时间里（雌性大鼠为36天），研究了雄性和雌性大鼠从自助餐饮食中自行选择的脂质、碳水化合物和蛋白质能量的比例。饮食包括12种不同的食物，从断奶到成年，每天都会在标准条件下过量提供给三只一组关在笼子里的大鼠。同时对对照组动物进行研究并与自助餐组进行比较。喂食自助餐饮食的大鼠组随着年龄的增长摄入更多能量，代谢效率降低。雄性大鼠比雌性大鼠吃得更多，即使雌性大鼠实际上停止生长后，雄性大鼠体重仍在增加。喂食自助餐的大鼠每天消耗的食物种类差异很大。然而，大鼠摄入的脂质、蛋白质和碳水化合物的比例保持不变。雄性大鼠比雌性大鼠摄入更多的脂质。对照组和喂食自助餐的大鼠组中，碳水化合物的摄入量与性别无关，保持恒定。自助餐组大鼠的蛋白质摄入量高于对照组，但差异不如脂质那么显著。自助餐饮食的纤维含量低于对照饮食。因此，大鼠选择的自助餐饮食热量和脂肪含量过高，碳水化合物含量与对照饮食基本相同，蛋白质含量略高，而且其成分随时间变化非常稳定。尽管观察到动物口味的变化以及它们对饮食中不同食物的不同消耗量，但所有这些趋势都得以维持。
