美国国家公共电台 NPR You May Live Longer By Severely Restricting Calories, Scientists Say

 

RACHEL MARTIN, HOST:

If you eat less food, can you live longer? Scientists have debated this question for years. Some studies in fish, rats and monkeys suggests that doing so actually can help you live longer. But there have been very few studies in humans. Now, some researchers have found that when people severely¹ cut down calories, they can slow their metabolism² and possibly the aging process. Here's NPR's Patti Neighmond.

PATTI NEIGHMOND, BYLINE³: The first challenge for this study was finding people willing to take part. After all, they were being asked to look at their typical plate for breakfast, lunch and dinner and cut it by 25 percent - one-fourth of what they normally ate in a day. And clinical physiologist⁴ Leanne Redman says none of them needed to lose weight.

LEANNE REDMAN: We enrolled⁵ normal-weight individuals.

NEIGHMOND: Redman headed the study at Pennington Biomedical Research Center in Baton⁶ Rouge⁷. Fifty-three healthy volunteers took part. One-third ate their regular meals. The rest were on the severe calorie reduction plan. Redman says the volunteers were committed.

REDMAN: I don't know if you understand the rigor⁸ of sort of what it means to do calorie restriction⁹ every day, which was the goal for two years.

NEIGHMOND: Not surprisingly, in the end, they lost quite a bit of weight - on average, 25 pounds. Those in the control group gained weight, as much as four pounds. But Redman says weight loss was not the point. She wanted to know whether this dramatic reduction in calories could affect how quickly people age. First, she looked at metabolism. For those on the restricted diet, it slowed and became more efficient.

REDMAN: Basically, it just means that cells are needing less oxygen in order to generate the energy that the body needs to survive. And so the body and the cells are becoming more energy efficient.

NEIGHMOND: And if less oxygen is needed to burn energy, then dangerous byproducts of that burning can be reduced.

REDMAN: Oxygen can actually be damaging to tissues and cells. And so if the cells have become more efficient, then they've got less oxygen left over that can cause this damage.

NEIGHMOND: And that damage can accelerate aging. The study also found blood pressure, cholesterol¹⁰ and triglycerides were lower in the group on severe calorie restriction. Now, these findings don't prove drastic calorie-cutting will actually help people live longer. People would have to be followed for their lifetimes to prove that. And in fact, lowering metabolism can cause other problems. Biochemist Valter Longo studies longevity¹¹ at the University of Southern California. He says severely restricting calories can mean you're more likely to gain weight in the end.

VALTER LONGO: Basically, you have to eat progressively less to maintain the same weight.

NEIGHMOND: And the fact of the matter is most Americans struggle with too much weight, which can cause countless¹² health problems.

LONGO: For most people, if you consider 70 percent of Americans are either overweight or obese¹³, then you can see how, for most people, this will be a big problem - having a slower metabolism that potentially could be carried for years.

NEIGHMOND: Instead of chronic¹⁴ calorie restriction, Longo's a proponent¹⁵ of mini-fasts, reducing calories to just 900 a day for five days every month. It may not lengthen¹⁶ your life, he says, but it certainly can help you maintain a healthy weight. Patti Neighmond, NPR News.

1 severely   

adv.严格地；严厉地；非常恶劣地

参考例句：

• He was severely criticized and removed from his post.他受到了严厉的批评并且被撤了职。
• He is severely put down for his careless work.他因工作上的粗心大意而受到了严厉的批评。

2 metabolism   

n.新陈代谢

参考例句：

• After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
• All living matter undergoes a process of metabolism.生物都有新陈代谢。

3 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

4 physiologist   

n.生理学家

参考例句：

• Russian physiologist who observed conditioned salivary responses in dogs (1849-1936). （1849-1936）苏联生理学家，在狗身上观察到唾液条件反射，曾获1904年诺贝尔生理学-医学奖。
• The physiologist recently studied indicated that evening exercises beneficially. 生理学家新近研究表明，傍晚锻炼最为有益。

5 enrolled   

adj.入学登记了的v.[亦作enrol]( enroll的过去式和过去分词 )；登记，招收，使入伍（或入会、入学等），参加，成为成员；记入名册；卷起，包起

参考例句：

• They have been studying hard from the moment they enrolled. 从入学时起，他们就一直努力学习。 来自《简明英汉词典》
• He enrolled with an employment agency for a teaching position. 他在职业介绍所登了记以谋求一个教师的职位。 来自《简明英汉词典》

6 baton   

n.乐队用指挥杖

参考例句：

• With the baton the conductor was beating time.乐队指挥用指挥棒打拍子。
• The conductor waved his baton,and the band started up.指挥挥动指挥棒，乐队开始演奏起来。

7 rouge   

n.胭脂，口红唇膏；v.(在…上)擦口红

参考例句：

• Women put rouge on their cheeks to make their faces pretty.女人往面颊上涂胭脂，使脸更漂亮。
• She didn't need any powder or lip rouge to make her pretty.她天生漂亮，不需要任何脂粉唇膏打扮自己。

8 rigor   

n.严酷，严格，严厉

参考例句：

• Their analysis lacks rigor.他们的分析缺乏严谨性。||The crime will be treated with the full rigor of the law.这一罪行会严格依法审理。

9 restriction   

n.限制，约束

参考例句：

• The park is open to the public without restriction.这个公园对公众开放，没有任何限制。
• The 30 mph speed restriction applies in all built-up areas.每小时限速30英里适用于所有建筑物聚集区。

10 cholesterol   

n.（U）胆固醇

参考例句：

• There is cholesterol in the cell of body.人体细胞里有胆固醇。
• They are determining the serum-protein and cholesterol levels.他们正在测定血清蛋白和胆固醇的浓度。

11 longevity   

n.长命；长寿

参考例句：

• Good habits promote longevity.良好的习惯能增长寿命。
• Human longevity runs in families.人类的长寿具有家族遗传性。

12 countless   

adj.无数的，多得不计其数的

参考例句：

• In the war countless innocent people lost their lives.在这场战争中无数无辜的人丧失了性命。
• I've told you countless times.我已经告诉你无数遍了。

13 obese   

adj.过度肥胖的，肥大的

参考例句：

• The old man is really obese,it can't be healthy.那位老人确实过于肥胖了，不能算是健康。
• Being obese and lazy is dangerous to health.又胖又懒危害健康。

14 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

15 proponent   

n.建议者；支持者；adj.建议的

参考例句：

• Stapp became a strong early proponent of automobile seat belts.斯塔普是力主在汽车上采用座椅安全带的早期倡导者。
• Halsey was identified as a leading proponent of the values of progressive education.哈尔西被认为是进步教育价值观的主要支持者。

16 lengthen   

vt.使伸长，延长

参考例句：

• He asked the tailor to lengthen his coat.他请裁缝把他的外衣放长些。
• The teacher told her to lengthen her paper out.老师让她把论文加长。