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，蔗糖是最可口，最受人欢迎的口味之一。从进化的角度来看，这并不奇怪，因为它是主要的能源。但是，过量食用会导致肥胖和相关的聚宝盆病，包括2型糖尿病和心血管疾病。在这里，我们描述了蔗糖摄入决策中涉及的三个生理水平的蔗糖：舌头，肠道和大脑。第一部分描述了甜味识别的外围细胞和分子机制，这些机制投射到较高的大脑中枢。我们认为用蔗糖刺激舌头会触发三个不同的途径，这些途径传达有关其质量，适口性和强度的感官属性，从而产生甜味感。我们还将讨论整个味觉通路中蔗糖的编码。第二部分回顾了蔗糖和其他可口食品如何通过肝门系统和/或迷走途径与肠-脑轴相互作用，从而编码了食品的有益价值和营养价值。第三部分回顾了控制食物摄入的体内稳态，享乐性和厌恶性大脑回路。最后，我们讨论证据表明，糖（或高脂饮食）的过度消费会削弱味觉，减味后的营养奖励价值以及控制饮食的回路，从而导致肥胖的发展。通过肝门系统和/或迷走途径与肠-脑轴相互作用，以某种方式编码食物的奖励和营养价值。第三部分回顾了控制食物摄入的体内稳态，享乐性和厌恶性大脑回路。最后，我们讨论证据表明，糖（或高脂饮食）的过度消费会削弱味觉，减味后的营养奖励价值以及控制饮食的回路，从而导致肥胖的发展。通过肝门系统和/或迷走途径与肠-脑轴相互作用，以某种方式编码食物的奖励和营养价值。第三部分回顾了控制食物摄入的体内稳态，享乐性和厌恶性大脑回路。最后，我们讨论证据表明，糖（或高脂饮食）的过度消费会削弱味觉，减味后的营养奖励价值以及控制饮食的回路，从而导致肥胖的发展。