根本停不下来！研究：垃圾食品正在改变你的“脑回路”

金黄焦香的炸鸡、香醇浓厚的巧克力、一口下去嘎嘣脆的薯片……我们好像总是很难抵挡这些高油高糖食品的诱惑。

不过要小心，这些垃圾食品，很有可能正在改变你的“脑回路”。

图源：视觉中国

A study published recently in the journalCell Metabolism suggests that eating fatty or sugary snacks alters our brain activity and creates lasting preferences for these less healthy items.

For the study, researchers at Yale University and the Max Planck Institute for Metabolism Research in Germany gave one group of participants a high-fat, high-sugar yogurt twice daily for eight weeks, while another got a low-fat, low-sugar version. Aside from that, both groups continued their normal eating habits.

图源：视觉中国

At the end, the groups rated puddings with varying fat concentrations and apple juices with a range of sugar levels.

The participants also underwent MRI scans. The scans showed that the treat increased brain activity in the group that had eaten the high-fat, high-sugar yogurt, but not in the other.

MRI scan 核磁共振扫描

The researchers concluded that fatty, sugary snacks activate the brain’s dopamine system, which gives people a feeling of motivation or reward.

如果你是“甜食爱好者”，一段时间不吃小点心，是不是会觉得百爪挠心、浑身难受呢？

“Let’s say a new bakery opens up next to your work and you start stopping in and having a scone every morning. That alone can rewire your basic fundamental dopamine learning circuits.”

“比方说，你办公室旁开了一家新面包店，你开每天早上会去买烤饼。这一个小小的饮食习惯会重新连接你多巴胺学习回路。”

Small said diet has such a strong effect on brain activity that dopamine signals can fire even when someone anticipates eating fatty or sugary food, like when they pass by a bakery or smell a pastry.

“It just tells us how sensitive we are to the food environment, and how the food environment can actually change our behavior.”

Food preferences aren't always something we're born with.

图源：视觉中国

"People think that we eat what we like, but we actually like what we eat."

“人们认为，我们是在吃自己喜欢的东西。但实际上，是我们喜欢我们在吃的东西。”

图源：视觉中国

"Perhaps it is the case that if you decrease gradually to more acceptable levels of fat, that eventually you can change your preferences in a more sustainable way. But I don’t think we know that," Small said.

“也许当你的脂肪逐渐减少到更可接受的水平，你可以以更可持续的方式改变你的饮食偏好。但这一点我们仍不确定。”

A 2012 study showed that after being routinely exposed to soup without added salt, people eventually liked those soups as much as saltier versions. Small said it's possible that such a process could work for fat and sugar, too.