Drivers of eating behaviour during chronic overconsumption: Role of food hedonics (liking & wanting) and peptide biomarkers on satiation and satiety.

这个项目将调查长期过度消费(卡路里摄入量过高)期间饮食行为的驱动因素。过度消费是导致体重增加和肥胖的主要原因之一。存在于许多发达国家的社会类型被认为代表了一种“顺从”的环境。这种类型的环境促进了食物的高消耗(以及鼓励久坐不动)，并产生了导致肥胖的快速体重增加。宜人的环境为人们提供了暴饮暴食的可能性。人们之所以能够吃太多食物，是因为享乐(愉悦相关)过程的过度激活，或者是因为体内平衡过程的缺陷。首先，这意味着人们会吃得更多，因为人们在进食过程中的快感增强，或者获得期待的食物的动机增强。这些(享乐)过程被称为“喜欢”和“想要”。其次，人们会吃得更多，因为他们的生理系统无法停止快速进食(导致大量进餐)，或者因为食物无法在进食后抑制他们的饥饿感。最后两个过程被称为“饱足”和“饱足”。吃的快感可以分为两个部分：喜欢和想要。虽然这些术语经常出现在一起，但它们是完全不同的。有时我们对我们喜欢的食物没有强烈的渴望；有时我们对不是特别喜欢的食物(例如土豆/主食)有强烈的渴望。重要的是，我们已经开发了衡量食物喜好和渴望的程序。目前尚不清楚过度消费是因为人们对某些食物的喜好增加，还是因为对这些食物的渴望增加。我们将确定在长时间暴饮暴食期间选择的食物类型，以及这在更大程度上是由喜欢还是想吃的增加推动的。同时，重要的是能够衡量控制膳食规模(饱腹感)和减少餐后饥饿(饱腹感)的过程的实际变化。我们将确定饮食的哪个方面在允许暴饮暴食/大餐或微弱抑制饥饿方面发挥主要作用。这将告诉我们如何使用特定的食物来控制这两个方面的饮食。能够将感觉和行为的变化与潜在的生理过程联系起来是很重要的。这意味着测量血液中已知与食欲控制有关的化学物质。其中一些化学物质被认为主要与饥饿(Ghrelin)或饱腹感(GLP1，CCK)或饥饿/饱腹感、喜好和想要(Leptin)有关。因此，我们将评估这些信号影响过度消费的具体方式。从长远来看，过度消费会导致体重增加，这种体重可能永远不会再下降，并可能损害健康。因此，我们开发了一种“安全”的过度消费模式，这种模式源于BBSRC一个刚刚完工的项目。当超重和肥胖的人自愿参加12周的有监督的日常锻炼计划(固定能量消耗)时，一些人减轻了体重，另一些人则没有。然而，与减肥无关的是，所有志愿者的心率、血压都有所下降，而体能(健康的关键)却有所增加。这种反应差异背后的原因是，没有减肥的反应不佳的人增加了食物摄入量，以抵消损失的能量。这一增加可被解释为过度消耗，相当于每天约290千卡。在缺乏锻炼的情况下，这将导致体重在一年内大幅增加6公斤以上。因此，我们可以使用这种“安全”的过度消费形式来检查潜在的行为驱动因素/喜好/欲望、饱足感和饱腹感的变化/以及它们与信号肽的关联。这为调查食物行为的驱动因素提供了一种相关的长期方法。

This project will investigate the drivers of eating behaviour that occur during a prolonged period of overconsumption (excess intake of calories). Overconsumption is important as a major cause of weight (re)gain and obesity. The type of society which exists in many developed countries is said to represent an 'obesigenic' environment. This type of environment facilitates a high consumption of food (as well as encouraging sedentariness) and generates rapid weight gain that leads to obesity. The obesigenic environment 'offers' the possibility for people to overeat. People are able to eat too much of some foods because of excessive activation of hedonic (pleasure related) processes, or because of a defect in homeostatic processes. Firstly this means that people will eat more because of elevated sensations of pleasure during eating or heightened motivation to obtain a looked-for food. These (hedonic) processes are termed 'liking' & 'wanting'. Secondly, people will eat more because their physiological systems fail to shut off eating quickly (leading to large meals) or because food fails to suppress their hunger after eating. These last two processes are called 'satiation' and 'satiety'. The pleasure of eating can be divided into two components /'liking' & 'wanting'. Although these terms often occur together, they are quite different. Sometimes we do not have a strong wanting for foods that we like a lot; at other times we have a strong wanting for foods that are not especially liked (e.g. potatoes/food staples). Importantly, we have developed procedures that measure both the liking & wanting of foods. It is not known if overconsumption results from an increase in liking for certain foods, or from an increase in wanting for those foods. We will identify the types of foods selected during a prolonged period of overeating and whether this is driven to a greater degree by increased liking or wanting. At the same time it is important to be able to measure the actual changes in processes that control meal size (satiation) and which lead to the reduction of hunger after eating (satiety). We will identify which aspect of eating plays the major role in allowing overeating /a large meal size, or weak suppression of hunger. This will inform us how to use specific foods to control these two aspects of eating. It is important to be able to relate changes in sensations and behavior to underlying physiological processes. This means measuring chemicals in the blood that are known to be involved in appetite control. Some of these chemicals are thought to be involved mainly in hunger (ghrelin) or in satiety (GLP1, CCK) or in both hunger/satiety, liking & wanting (leptin). We will therefore assess the particular ways in which these signals influence overconsumption. Generating overconsumption in the long term leads to a gain in weight which may never be lost again and could impair health. We have therefore developed a 'safe' model of overconsumption that has arisen from a BBSRC project just finished. When overweight and obese people volunteer for a 12 week programme of supervised daily exercise (of fixed energy expenditure) some individuals lose weight and others do not. However, independent of weight loss all volunteers show decreases in heart rate, blood pressure, and an increase in fitness (key to becoming healthy). The reason behind this variability in response is that the poor responders who do not lose weight have increased their food intake to negate the energy lost. This increase can be interpreted as overconsumption and amounts to ~290 kcal/day. In absence of exercise this would lead to a dramatic weight increase of more than 6kg over a year. Therefore we can use this 'safe' form of overconsumption to examine changes in underlying behavioral drivers /liking & wanting, satiation and satiety/ and their association with signalling peptides. This provides a relevant long term method for investigating the drivers of food behaviour.