Question

  We know the effect calories have on your body. For each pound of weight that your body carries,it takes about 12 calories per pound per day to keep it alive. If you weigh 150 pounds, you therefore need about 1 ， 800 calories per day to keep yourself alive and maintain that same weight.

If you were to eat more than 1 ， 800 calories per day,the surplus(剩余) turns into fat. It takes about 3,600 excess(過量的) calories to make a pound of fat.

  Let's say that you were to eat,on average, 2,000 calories per day. That extra 200 calories per day is going to turn into fat. However, you will eventually hit a point of equilibrium(平衡， 均衡) because as you gain weight, you need more calories to maintain that weight. So,a person eating an average of 2,000 calories per day will hit equilibrium at (2,000/12) 166. 67 pounds.

  So let's say that you eat,on average, 2 ， 000 calories per day and reach equilibrium at 166 pounds. Then you go on a crash diet where you eat only 1 ， 000 calories per day for 60 days. You lose 16 pounds and reach your target weight of 150 pounds. But then you go right back to eating 2 ， 000 calories per day again. The graph below shows your eating pattern before, during and after the diet：

Note that the graph assumes that you,like most people, eat a random(無計(jì)劃的) number of calories per day. Some days you are "good" and eat less,and some days you are "bad" and eat more,but the assumption is that it averages out to 2， 000 calories per day over the long run.

This graph shows what happens to your weight before ，during and after the diet ：

  

 The diet really takes the weight off. But the weight comes right back when you return to your "normal" eating pattern. The weight appears to come back so quickly because when you are at your lightest,you tend to gain more weight each day. The lighter you are,the fewer calo?ries you need. If you only need 1,500 calories per day and you're eating 2,000,you're going to gain weight faster than if you need 1,800 and you're eating 2,000.

There are only two ways to keep the weight off ：

Change your overall eating pattern so that you take in,on average,fewer calories than be?fore you go on the diet.

Start exercising so that you "burn" the extra calories you take in.

The best course of action is a combination of these two choices.

(   ) 5. The problem that the writer tries to deal with is        .

   A. how to lose weight fast while changing the diet

   B. why the weight comes back so quickly once one stops dieting

   C. how to reach the point of equilibrium

   D. what your target weight is

(   ) 6. What can we learn from the two graphs?

   A. It is hard to keep one's normal weight.

   B. The better way for you to lose weight is keeping your dieting.

   C. You will gain weight faster than before dieting.

   D. It is not necessary for you to lose weight by dieting.

(   ) 7. According to the passage,if you weighed 100 pounds and you were to eat on average 1400 calories per day,a year later,you would be        .

   A. 100 pounds

   B. 166. 67 pounds

   C. 97 pounds

   D. 116. 67 pounds

(   ) 8. What is the best way to keep the weight off according to the passage?

   A. Keep your diet and never stop.

   B. Return your overall eating pattern and exercise more.

   C. Take in fewer calories than before your diet and exercise more.

   D. Go on your diet and start exercising to burn the extra calories.

Answer 1

5-8 BCDC

B篇從科學(xué)的角度解釋了為什么人們停止節(jié)食后體重迅速反彈的原因。

5.B細(xì)節(jié)理解題。從倒數(shù)第四段可知作者進(jìn)行分析的目的是解釋一旦停止節(jié)食，反彈就會迅速出現(xiàn)的原因。

6.C邏輯推理題。通過兩個圖的比較及說明，我們可以知道節(jié)食后，因?yàn)槟愕捏w重減低，所需要的能量小了，而一旦停止節(jié)食，攝人量和需求量的差距增大，你儲存的熱量就增多，那么，轉(zhuǎn)化成脂肪的速度增快，你就增重較快。

7.D數(shù)字計(jì)算題。100磅的人每天需1200 calories的熱量，每天增加200 calories，一年可增體重16. 67磅，所以選D項(xiàng)。

8.C邏輯推理題。從最后一段可推斷出1.要停止節(jié)食后的攝人量要比節(jié)食前少，注意，作者沒有要求你一直節(jié)食;2.增加運(yùn)動量，消耗脂肪。