Department of Psychology, Drexel University, Philadelphia, Pennsylvania, USA.
Obesity (Silver Spring). 2014 May;22(5):E38-45. doi: 10.1002/oby.20599. Epub 2013 Sep 20.
Prior neuroimaging research has shown that restrained and unrestrained eaters demonstrate differential brain activation in response to food cues that parallels their food intake in lab studies. These findings were extended by comparing brain activation in response to food cues in normal weight nondieters, historical dieters, and current dieters under the conditions that mimicked past lab studies.
Participants (N = 30) were shown pictures of highly and moderately palatable food and neutral cues while being scanned in an fMRI BOLD paradigm following an 8-h fast and again after a liquid meal.
In the Fed state, historical dieters showed elevated reward circuitry activation in response to highly palatable food, as compared to nondieters and current dieters. In contrast, current dieters did not show the same pattern of activation as historical dieters, despite their shared history of frequent weight-loss dieting.
The parallels between eating behavior and regional brain activation across groups suggest that (1) a neurophysiological response which could represent a vulnerability to overeat exists in some normal weight young women that may increase susceptibility to weight gain in the long term, and (2) current dieting temporarily reverses this vulnerability.
先前的神经影像学研究表明，在对食物线索做出反应时，有约束和无约束的进食者的大脑激活存在差异，这与他们在实验室研究中的食物摄入量相平行。通过比较正常体重非节食者、历史节食者和当前节食者在模拟过去实验室研究条件下对食物线索的大脑反应，扩展了这些发现。
参与者（N=30）在进行 fMRI BOLD 范式扫描时，禁食 8 小时后，再次在禁食状态下和进食后，分别接受高度和中度美味食物以及中性线索的图片刺激。
在进食状态下，与非节食者和当前节食者相比，历史节食者在对高度美味食物做出反应时，奖赏回路的激活程度更高。相比之下，尽管当前节食者有频繁的减肥节食史，但他们并没有表现出与历史节食者相同的激活模式。
各组之间的进食行为和区域大脑激活之间存在相似性，表明（1）在一些正常体重的年轻女性中，存在一种可能代表过度进食倾向的神经生理反应，这可能会增加长期体重增加的易感性，（2）当前的节食行为暂时逆转了这种脆弱性。
