VOA标准英语2011--Some Fatty Foods Trigger Natural High

Some Fatty Foods Trigger Natural High

Ever wonder why foods that are bad for you - such as fat-laced potato chips and French fries - taste so good? It turns out they follow the same pleasure-inducing biochemical pathways through the body as marijuana does, encouraging people to keep eating even when they know they should stop.
There used to be an old television commercial in the United States that boasted a certain brand of potato chip tasted so good, you could never eat just one. It turns out there is a biological reason for that.
Fat is an important component¹ of healthy human cell membranes² and high-fat foods, which are rare in the wild, and were prized by early humans as a rich source of energy. As a result, says Daniele Piomelli at the University of California, Irvine, humans developed a biological preference for fatty foods.
"The mechanisms³ that have evolved to make animals eat as much as possible now are turning against us because now fat is everywhere," says Piomelli. "We have fat in our refrigerators, in our cabinets in the kitchen and it is very easy for us to eat too much of it because of this long evolution that has taught us that it is rare and hard to find."
Piomelli's team has discovered a biological pathway that encouraged ancient humans to eat large quantities of the scarce nutrient⁴ - whenever they found it - to ensure their survival. Today, eating fat still provokes feelings of pleasure and satisfaction, similar to the high people get when smoking marijuana.
According to Piomelli, when fatty foods are swallowed and hit the upper digestive tract⁵, they trigger the production of endocannabinoids. That's the same class of feel-good brain chemicals that marijuana, or cannabis, stimulates⁶ in the brain.
Endocannabinoids in the gut⁷ send a surge of cell-signaling to the brain, which shoots back a message telling the body to keep eating.
Piomelli's team discovered the fat pathway in research with rats. The rats didn't like sugar water or water laced with protein as much as they liked oily water. The animals continued to consume the oil water until they were full, which is the body's natural signal to stop eating.
But since fats contain more calories than carbohydrates⁸ or proteins combined, waiting for satiety⁹, or fullness, is not necessarily the best strategy to limit consumption of fatty foods.
Piomelli says researchers are interested in developing drugs that target endocannabinoids in the digestive tract to help people with their fatty food cravings.
"When some people eat fat, they eat it in large amounts - for example a pint¹⁰ of ice cream or a whole bag of potato chips. And hopefully by using these type of medications, we can decrease overweight and obesity¹¹."

1 component   

n.组成部分，成分，元件；adj.组成的，合成的

参考例句：

• Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。
• Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。

2 membranes   

n.（动物或植物体内的）薄膜( membrane的名词复数 )；隔膜；（可起防水、防风等作用的）膜状物

参考例句：

• The waste material is placed in cells with permeable membranes. 废液置于有渗透膜的槽中。 来自辞典例句
• The sarcoplasmic reticulum is a system of intracellular membranes. 肌浆网属于细胞内膜系统。 来自辞典例句

3 mechanisms   

n.机械( mechanism的名词复数 )；机械装置；[生物学] 机制；机械作用

参考例句：

• The research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
• He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》

4 nutrient   

adj.营养的，滋养的；n.营养物，营养品

参考例句：

• Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
• The roots transmit moisture and nutrient to the trunk and branches.根将水分和养料输送到干和枝。

5 tract   

n.传单，小册子，大片(土地或森林)

参考例句：

• He owns a large tract of forest.他拥有一大片森林。
• He wrote a tract on this subject.他曾对此写了一篇短文。

6 stimulates   

v.刺激( stimulate的第三人称单数 )；激励；使兴奋；起兴奋作用，起刺激作用，起促进作用

参考例句：

• Exercise stimulates the body. 运动促进身体健康。 来自《简明英汉词典》
• Alcohol stimulates the action of the heart. 酒刺激心脏的活动。 来自《现代英汉综合大词典》

7 gut   

n.[pl.]胆量；内脏；adj.本能的；vt.取出内脏

参考例句：

• It is not always necessary to gut the fish prior to freezing.冷冻鱼之前并不总是需要先把内脏掏空。
• My immediate gut feeling was to refuse.我本能的直接反应是拒绝。

8 carbohydrates   

n.碳水化合物，糖类( carbohydrate的名词复数 )；淀粉质或糖类食物

参考例句：

• The plant uses the carbohydrates to make cellulose. 植物用碳水化合物制造纤维素。 来自《简明英汉词典》
• All carbohydrates originate from plants. 所有的碳水化合物均来自植物。 来自辞典例句

9 satiety   

n.饱和；(市场的)充分供应

参考例句：

• There is no satiety in study.学无止境。
• Their presence in foods induces satiety at meal time.它们在食物中的存在诱导进餐时的满足感。

10 pint   

n.品脱

参考例句：

• I'll have a pint of beer and a packet of crisps, please.我要一品脱啤酒和一袋炸马铃薯片。
• In the old days you could get a pint of beer for a shilling.从前，花一先令就可以买到一品脱啤酒。

11 obesity   

n.肥胖，肥大

参考例句：

• One effect of overeating may be obesity.吃得过多能导致肥胖。
• Sugar and fat can more easily lead to obesity than some other foods.糖和脂肪比其他食物更容易导致肥胖。