你是不是和风铃一样，明明肚子已经饱到不行，但是嘴却还是忍不住的想吃零食？最近一个研究就对这种现象进行了解释，到底是怎么回事呢？让我们一起来看看吧。

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You've tried every diet. You know to never eat standing at the fridge, you know to cut back on sugar, fat and other calorie-dense foods. You know to only eat when you are hungry and to stop when you're full.
你试遍了各种节食方法，你知道不能站在冰箱前吃东西，也知道少吃那些糖，脂肪和其它卡路里含量高的食物，你还知道只有在饿的时候才能吃东西，饱了以后就不能再吃了。

But people are still driven to snack - even when they aren't hungry any more. It's fueling the obesity epidemic and helps explain why virtually every diet fails.
可是人们在一点儿都不饿时，仍想吃点零食。这加剧了肥胖的盛行，也解释了为什么几乎每一次的节食都失败。

Now, researchers may have found one little piece of the puzzle. It turns out your brain may have a system for making you want to snack.
目前，研究员们可能掀开了谜题的一角。研究表明你的大脑中可能有一个想让你吃零食的系统。

There's a whole class of neurons that motivate animals to eat.
有一整类会促使动物进食的神经元存在。

They found a similar group of neurons called the subfornical organ or SFO neurons that controlled drinking behavior.
研究人员还发现了一组具有类似功能的神经元，名为穹窿下器，或穹窿下器神经元，控制着饮酒行为。

A second team at Beth Israel Deaconess Medical Center and the National Institute of Diabetes and Digestive and Kidney Diseases made similar findings.
另一支来自迪肯尼斯医疗中心和国家糖尿病、消化病及肾病研究所的团队也有类似的研究结果。

"When these neurons are 'turned on,' either by fasting or by artificial means, laboratory animals eat voraciously," said Dr. Bradford Lowell of Beth Israel Deaconess, who helped lead the study.
迪肯尼斯医疗中心的布拉德福德•洛威尔教授是研究的带头人，他表示：“当这些神经元开启时，不论是在断食后，或是通过一些人为方法干预，实验室的动物都会狼吞虎咽地进食。

”Lowell says the neurons sense the low energy reserves, activate, and release brain-signalling chemicals called neurotransmitters that shut off brain cells that make an animal feel full.
洛威尔说，这些神经元能够感知能量储存的水平，并在能量储存较低时刺激并释放名为神经递质的脑部信号类化学物质，来关闭那些让动物有饱腹感的脑细胞。

Lowell says there's another mechanism, also. "There is a major hypothesis called 'Drive Reduction' that proposes that you eat to get rid of the unpleasant feeling of hunger," he said.
洛威尔称还有另外一种机制：“有一个名为“驱力降低论”的重要假说，认为你进食的目的是为了摆脱令人不快的饥饿感。

”His team genetically engineered mice that had this system turned on, and whose brains were also altered so that a blue light activated nerve cells that 'told' the mice they had eaten. Normal mice moved around a cage system randomly, but the genetically engineered mice sought out a little room where the blue light turned off their hunger drive, they report in the journal Nature Neuroscience.
他的团队对实验鼠进行了基因改造，以开启这一系统，这些实验鼠的大脑也经过了改造，经过蓝光激发的神经细胞会使实验鼠产生饱腹感。普通实验鼠会在笼子里随意地活动，而基因改造过的实验鼠则会寻找照射蓝光的小区域，以关闭其饥饿冲动，这一发现发表在《自然-神经科学》杂志上。

"Our findings suggest that the therapeutic targeting of these cells may reduce both food consumption and the aversive sensations of hunger - and therefore may be an effective treatment for obesity," Lowell said.
“我们的发现显示，以这些细胞为目标可能会减少食物摄入量以及令人厌恶的饥饿感，因此或许会成为肥胖症的有效治疗方式。”洛威尔说。

Obviously, it's not possible to genetically engineer people in the same way as mice, but it might be possible to find a drug that activates the same switches.
很显然，我们不可能随意对人类进行实验中的基因改造，但可能会找到开启那些相同开关的某种药物。