Impact of feeding on brain response to food stimuli in lean and obese subjects

描述(申请人提供)：以前对人类食欲的研究仅限于使用视觉模拟标尺和食物摄入量测量。随着新的大脑成像技术的使用，我们现在可以在体内检查大脑对食物刺激的反应。我们最近开发并测试了一种功能磁共振成像(FMRI)方案，以研究大脑对食物刺激的反应。我们建议使用这一方案来检查和比较瘦身和肥胖受试者在禁食和进食状态下对食物刺激的大脑反应。12名苗条的女性和12名肥胖的女性将在隔夜禁食和标准餐后接受扫描。功能磁共振成像方案将由一个模块设计组成，在该设计中，受试者在观看真实食物和非食物物品以及触摸食物和非食物物品时进行扫描。在空腹功能磁共振成像方案之后，瘦的和肥胖的受试者将摄入一顿流质餐，提供他们估计能量需要量的35%。这顿饭将在20分钟内用完，随后的fMRI扫描将在用餐后30分钟进行。大脑中那些在视觉上和触觉上被食物激活，但在非食物中视觉和触觉上不被激活的区域将被认为是由于食物而激活的。这些研究将使我们能够检查基于体重和进食状态的个体大脑反应的差异。如果瘦人和肥胖人的大脑对食物刺激的反应不同，长期目标是确定肥胖人对食物刺激的大脑反应是否可以随着体重的减轻而改变，并检查健康的瘦人和厌食症患者对食物刺激的大脑反应是否存在差异。这项研究的结果将有助于在人类整个大脑水平上为研究对食物的综合反应奠定基础，并将为一系列创新的实验范式奠定基础。

DESCRIPTION (provided by applicant): The study of appetite in humans has previously been confined to the use of visual analog scales and food intake measurements. With the use of new brain imaging techniques, we can now examine brain activity in response to food stimuli in vivo. We have recently developed and tested a functional magnetic resonance imaging (fMRI) protocol to study brain responses to food stimuli. We propose to use this protocol to examine and compare brain responses to food stimuli in lean and obese subjects in the fasted and fed states. Twelve lean and 12 obese women will be scanned after an overnight fast and after a standard meal. The fMRI protocol will consist of a block design in which subjects will be scanned when viewing real foods and non- food items and when touching foods and non-food items. After the fasting fMRI protocol, lean and obese subjects will consume a liquid meal providing them with 35% of their estimated energy requirements. The meal will be consumed within a 20-minute period and the subsequent fMRI scan will be taken 30 minutes following meal consumption. Brain regions that are more robustly activated both visually and tactilely with food but not also activated visually and tactilely with non-foods will be considered to be activated due to foods. These studies will allow us to examine differences in individual's brain responses based on their body weight and feeding status. If brain responses to food stimuli are different between lean and obese individuals, the long-term goals are to determine whether the brain responses of obese individuals to food stimuli can be modified with weight loss and to examine whether there are differences in brain responses to food stimuli between healthy lean individuals and anorexics. Results of this study will help create the foundation for the study of integrative responses to foods at the whole brain level in humans and will set the stage for a series of innovative experimental paradigms.