Throughout the animal kingdom sucrose is one of the most palatable and preferred tastants. From an evolutionary perspective, this is not surprising as it is a primary source of energy. However, its overconsumption can result in obesity and an associated cornucopia of maladies, including type 2 diabetes and cardiovascular disease. Here we describe three physiological levels of processing sucrose that are involved in the decision to ingest it: the tongue, gut, and brain. The first section describes the peripheral cellular and molecular mechanisms of sweet taste identification that project to higher brain centers. We argue that stimulation of the tongue with sucrose triggers the formation of three distinct pathways that convey sensory attributes about its quality, palatability, and intensity that results in a perception of sweet taste. We also discuss the coding of sucrose throughout the gustatory pathway. The second section reviews how sucrose, and other palatable foods, interact with the gut–brain axis either through the hepatoportal system and/or vagal pathways in a manner that encodes both the rewarding and of nutritional value of foods. The third section reviews the homeostatic, hedonic, and aversive brain circuits involved in the control of food intake. Finally, we discuss evidence that overconsumption of sugars (or high fat diets) blunts taste perception, the post-ingestive nutritional reward value, and the circuits that control feeding in a manner that can lead to the development of obesity.

在整个动物界中，蔗糖是最美味和最受欢迎的促味剂之一。从进化的角度来看，这并不奇怪，因为它是主要的能量来源。然而，过度食用可能会导致肥胖和相关疾病，包括 2 型糖尿病和心血管疾病。在这里，我们描述了参与决定摄入蔗糖的三个生理水平：舌头、肠道和大脑。第一部分描述了投射到高级大脑中枢的甜味识别的外周细胞和分子机制。我们认为，用蔗糖刺激舌头会触发三种不同途径的形成，这些途径传递有关其质量、适口性和强度的感官属性，从而产生甜味感知。我们还讨论了蔗糖在整个味觉通路中的编码。第二部分回顾了蔗糖和其他可口食物如何通过肝门系统和/或迷走神经通路与肠脑轴相互作用，以编码食物的奖励和营养价值的方式。第三部分回顾了与控制食物摄入有关的稳态、享乐和厌恶大脑回路。最后，我们讨论了过量摄入糖（或高脂肪饮食）会削弱味觉、摄入后营养奖励价值以及控制进食的回路的证据，从而导致肥胖的发生。