Carbohydrate Appetite, Fat Appetite and Obesity

描述（由申请人提供）：肥胖目前是一个主要的健康问题，增加了许多疾病的风险，包括糖尿病，心脏病，高血压和某些形式的癌症。超重和肥胖个体的日益普遍部分归因于环境因素，例如富含糖和脂肪的美味、能量密集的食物的丰富。高糖和高脂肪食物也会促使实验动物暴饮暴食和肥胖。高糖和高脂肪食物的口腔感觉特性（风味）显然对动物有吸引力，并有助于饮食诱导的暴饮暴食。此外，这些营养素的口服后作用显着增强碳水化合物和脂肪的食欲。口服后营养素的作用最初被认为是完全抑制（饱腹）的性质，但最近的研究结果表明，营养素具有积极的（刺激）postingestive的后果，影响食物的选择和消费，通过调节风味偏好和接受。在进餐期间出现的饱食可以掩盖口服后营养素对摄入的最初刺激，这阻碍了对这些早期效应的研究。使用一种新的方法，拟议的研究将获得更具体的条件反射过程，促进正在进行的膳食中的摄入，并在随后的膳食中赋予该食物更大的吸引力。将已经消耗与口服后水配对的温和可口的调味溶液的动物转换为与口服后营养物配对的新风味，并监测它们的摄食反应的变化。在第一次肠道营养刺激中摄入量的增加表明营养物质已被检测到，并且信号已到达大脑。通过其他方法，包括使用缺失推定的传感和信号传导机制的元件的敲除小鼠模型，将研究这种关联过程的组成部分。该应用程序的总体目标是确定口腔感觉和口腔后感觉刺激与碳水化合物和脂肪食欲的获得相关的过程。本项目的具体目标是：1）研究碳水化合物刺激摄入和风味偏好学习; 2）研究脂肪刺激摄入和风味偏好学习; 3）评估脂肪味道和口服后反馈对脂肪食欲的作用以及营养偏好的个体差异。这项研究涉及心理学、营养学和胃肠道生理学领域。了解风味如何与食物的奖励特性，加强偏好和导致暴饮暴食联系起来，对于找到限制食物促进摄入效果的方法至关重要。这些知识也可以应用于厌食症和恶病质的临床病例中促进进食。 公共卫生相关性：这个项目将研究碳水化合物和脂肪刺激进食的过程，并导致对这些营养素含量高的食物的偏好。发现营养刺激进食的控制机制将有助于开发治疗暴饮暴食、肥胖和厌食症的方法。

DESCRIPTION (provided by applicant): Obesity is currently a major health problem that increases the risk of many diseases, including diabetes, heart disease, hypertension and some forms of cancer. The growing prevalence of overweight and obese individuals is attributed, in part, to environmental factors such as the abundance of palatable, energy dense foods that are rich in sugar and fat. High-sugar and high-fat foods also promote overeating and obesity in laboratory animals. The orosensory properties (flavor) of high-sugar and high-fat foods are clearly attractive to animals and contribute to diet-induced overeating. Furthermore, the post-oral actions of these nutrients significantly enhance carbohydrate and fat appetites. Post-oral nutrient actions were initially considered to be exclusively inhibitory (satiating) in nature, but recent findings demonstrate that nutrients have positive (stimulating) postingestive consequences that influence food choice and consumption by conditioning flavor preference and acceptance. The onset of satiation during meals can mask the initial stimulation of intake by post-oral nutrients, which has hindered the study of these early effects. Using a new method, the proposed studies will obtain more specific access to the conditioning process that promotes ingestion in an ongoing meal and confers greater attraction to that food in subsequent meals. Animals that have been consuming a mildly palatable flavored solution paired with post-oral water are shifted to a new flavor paired with post-oral nutrient, and the changes in their ingestive responses are monitored. Increased intake in the first session of intestinal nutrient stimulation indicates that the nutrient has been detected and a signal has reached the brain. With additional methods, including the use of knockout mouse models missing elements of putative sensing and signaling mechanisms, the components of this associative process will be investigated. The overall goal of this application is to determine the processes by which orosensory and post-oral sensory stimuli become linked in the acquisition of carbohydrate and fat appetite. The specific aims of this project are to 1) Investigate carbohydrate stimulation of intake and flavor preference learning; 2) Investigate fat stimulation of intake and flavor preference learning; and 3) Evaluate the role of fat taste and post-oral feedback on fat appetite and individual differences in nutrient preferences. This research involves the fields of psychology, nutrition, and gastrointestinal physiology. Understanding how flavors become linked to rewarding properties of foods, strengthening preferences and leading to overeating is crucial to finding ways to limit the intake-promoting effects of foods. This knowledge may also be applied to promote eating in clinical cases of anorexia and cachexia. PUBLIC HEALTH RELEVANCE: This project will examine the processes by which carbohydrates and fats stimulate eating and lead to preferences for foods high in these nutrients. Discovering the controls of nutrient-stimulated eating will assist the development of treatments for overeating and obesity as well as for anorexia.