听力文本

This is Scientific American — 60-Second Science. I'm Karen Hopkin.
Potato chips! Does the mere mention of the salty snack send you searching for a vending machine? Well, you can blame the one-two punch of fat and carbohydrates, because a new study finds that foods high in both carbs and fats tickle the brain's reward circuits more so than snacks that showcase just one or the other. The findings are served up in the journal Cell Metabolism.
"The energetic properties of foods play an important role in determining their value."
Dana Small, professor of psychiatry at Yale University School of Medicine.
The big players, calorically speaking, are fats and sugars. And the reason we desire them is because they activate our neural reward system, flooding those brain regions with the neurotransmitter dopamine. But studies show that fats and sugars trigger those rewarding bursts of dopamine in different ways.
"This really got us thinking. Modern processed foods like french fries, donuts, hamburgers and even yogurts contain high levels of fat and carbohydrate. In contrast, foods high in fat and carbohydrate are very rare, if they ever existed at all, in the natural food environment. So we wondered, if fat and carbohydrate both release dopamine, might it be the case that their simultaneous consumption produces a superadditive response, resulting in foods that are more reinforcing, calorie for calorie?"

To find out, the researchers set up a sort of snack-attack auction. Participants were given some spending money, then shown pictures of familiar foods and invited to bid. The edible items fell into three categories: those high in fats but low in carbs, like cheeses; those packed with carbs but lacking fats, like pretzels; and those that were full of both, like cookies.
The results?
"We found that participants bid more money for foods that contained fats and carbohydrate than either macronutrient group alone, even though the food portions in the pictures had an equal number of calories across categories and they were equally liked."
Alexandra DiFeliceantonio is an associate research scientist in Dr. Small's lab.
"So that means that calorie for calorie, foods containing fat and carbohydrates are more reinforcing, or in other words, more valuable, than either macronutrient group alone."
That additive effect of fats and carbs was apparent in brain imaging that was done as the participants prepared their bids.
"So we were able to demonstrate for the first time, in any species, that the value of food is not just related to the energy it provides or even how much we like it. Instead we provide evidence that these very old systems that developed to convey nutritional information to the brain are, in a way, tricked by modern foods that have nutrients in combinations not found in nature."
The findings suggest how that crave-causing combination of carbs and fat can lead to overeating—and why even if you're a tough cookie, you'll likely crumble when presented with chocolate-chip goodies.
Thanks for listening for Scientific American — 60-Second Science. I'm Karen Hopkin.

参考译文

这里是科学美国人——60秒科学(K6x[nHuZg。我是凯伦·霍普金7XGvg#EvZuXUJqYtk。
薯片！仅仅提到这种咸味零食就会使你去找自动售货机吗？你可以把这归咎于脂肪和碳水化合物的双重作用所引发的结果，因为一项新研究发现，高碳水化合物和高脂肪的食物，比零食更能刺激大脑回路hrw!w%SUr3AHTGl。这项研究结果发表在《细胞代谢》期刊上_C,x*Y@Lyr_d。
“食物的能量特性在决定其价值方面起着重要作用cU]E8T]]rLjt3!4J3。”
黛娜·斯莫尔是耶鲁大学医学院的精神病学教授BEh(s|R-u,&H。
从卡路里的角度来说，最大的能量玩家是脂肪和糖.iLDqluhM|A|,h.Hk。我们渴望它们的原因是，它们激活了我们的神经奖励系统，让这些大脑区域充满了神经递质多巴胺.Yz(7vF1~D*o。但研究结果表明，脂肪和糖触发有益多巴胺释放的方式并不相同&HZp*1T6MPF。
“这不禁令我们思考OXIb;~aWg,#ME%t,。薯条、甜甜圈、汉堡、甚至是酸奶这些现代加工食品都含有高比重的脂肪和碳水化合物RbDf[@3]C8E9N4WrL。相反，高脂肪和高碳水化合物的食物在自然食物环境中极为罕见，如果它们曾存在过的话ps,3J;^bBQFzndL~sCJ。所以我们想知道，如果脂肪和碳水化合物都释放多巴胺，那同时摄入这两种时会产生超加反应吗？会催生能量更强、卡路里叠加的食物吗？”
为了找到答案，研究人员设置了一种零食攻击拍卖实验t3D*a8]&yCUY^S。研究人员会给参与者一些零花钱，然后给他们展示一些熟悉食物的图片，并邀请他们进行投标uQMG9i2HFe0mHL&_=(。可食用的食物被分成三类：高脂肪低碳水化合物的食物，比如奶酪；富含碳水化合物但缺乏脂肪的食物，如椒盐脆饼；两者均丰富的食物，如饼干#,DU^_dFQ,ext%。
结果如何？
“我们发现，参与者对含有脂肪和碳水化合物的食物的出价，比仅含有一种营养素的食物的出价要高，尽管图片里各个类别的食物分量具有相同的卡路里含量，而且受欢迎程度也是一样的)_h[AX6J1Mb&E8V[[UtL。”
亚历山德拉·迪菲里西恩托尼奥是斯莫尔博士实验室的副研究员lY1_Xep7.o=]G&s。
“所以，这意味着超级卡路里、含有脂肪和碳水化合物的食物比仅含有一种营养素的食物更强，也就是说，更具价值]_kD47,b!)3C。”
在参与者准备出价时所形成的脑成像中，脂肪和碳水化合物的附加作用非常明显N;Er,w6cWbc2。
“因此，我们能够首次证明，无论任何种类，食物的价值不仅仅与其提供的能量或我们对其的喜爱程度有关4H+w!%o2os。相反，我们提供的证据表明，这些用来向大脑传递营养信息的古老系统，从某种程度上来说，受到了现代食物的欺骗，这些现代食物的营养成分组合在自然界中并不存在nD[cFsv0p[B。”
研究结果表明了这种激发渴望的碳水化合物和脂肪的组合是如何令人暴饮暴食的，还有，即使你是一个严格的人，你在面对巧克力美食时意志也会瓦解的原因mGA.RM1YQHR3p。
谢谢大家收听科学美国人——60秒科学rq~Ty4dogSQL!|B。我是凯伦·霍普金kYZUXwnXb-l@。

译文为可可英语翻译，未经授权请勿转载！

重点讲解

重点讲解：
1. in contrast 相比之下；与…相反；
In contrast, the lives of girls in well-to-do families were often very sheltered.
相反，生活在富裕家庭的女孩子通常都备受呵护Klo]3;q7aOm#l(Lip%C5。
2. result in 导致；引起；造成；
Competition can be healthy, but if it is pushed too far it can result in bullying.
竞争可以是良性的，但如果太过火，就可能造成以强凌弱d@=AG8u![rsbPjdN。
3. fall into 属于；被划分为；
These books fall into several categories.
这些书可分成几类jXfGHAu9TU_bYBoH。
4. in a way (用于缓和语气)在某种程度上，在某些方面；
As I said at the beginning, in a way Wall Street's self-centered, self-absorbed behavior has been kind of funny.
正如我在文章开始说的，在某种程度上，华尔街这种以自我为中心的，孤芳自赏的行为有点可笑Y4E0^uAdG7xUT;。