Koehnle Thomas J, Stephens Angel L, Gietzen Dorothy W
Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, One Shields Avenue, University of California, Davis, CA 95616, USA.
Physiol Behav. 2004 Mar;81(1):15-21. doi: 10.1016/j.physbeh.2003.11.009.
Diets limiting in an essential amino acid have long been known to suppress food intake. The purpose of this study was to examine the microstructure of feeding behavior of rats within the very first meal of an imbalanced diet. Rats were preconditioned for 12 days on a Baseline diet and were then given a test diet with either a corrected amino acid profile or a diet imbalanced with respect to the essential amino acid threonine. Overall, first-meal intake and first-meal duration were robustly and significantly reduced by the Imbalanced diet but not altered by the Corrected diet. The Corrected diet caused an increase in the number of feeding bouts during the first meal. The Imbalanced diet increased the duration of pauses during the first meal. Most rats in the Imbalanced group stopped eating after just 15 min of exposure to the diet, but those still eating after this time tended to have a lower rate of eating compared to those eating the Corrected diet. On the basis of these results, we conclude that changes in microstructure and meal duration contribute to the reduction in food intake upon exposure to amino-acid-deficient diets.
长期以来，人们都知道限制必需氨基酸的饮食会抑制食物摄入。本研究的目的是在不平衡饮食的第一餐期间，研究大鼠进食行为的微观结构。大鼠先在基础饮食上适应12天，然后给予氨基酸谱校正的测试饮食或必需氨基酸苏氨酸不平衡的饮食。总体而言，不平衡饮食显著减少了第一餐的摄入量和持续时间，但校正饮食未对其产生影响。校正饮食使第一餐期间的进食次数增加。不平衡饮食增加了第一餐期间的停顿时间。不平衡组的大多数大鼠在接触该饮食仅15分钟后就停止进食，但在此之后仍在进食的大鼠与进食校正饮食的大鼠相比，进食速度往往较低。基于这些结果，我们得出结论，微观结构和进餐持续时间的变化导致了暴露于氨基酸缺乏饮食时食物摄入量的减少。
