题目内容：

阅读下面材料,在空白处填入适当的内容(1 个单词)或括号内单词的正确形式

Scientists have found a reliable way to lengthen life in lab animals:Reduce the amount of calories(卡路里)they eat.

This method,1.(know)as caloric restriction, has been shown to lengthen life of organisms ( 有 机体 )and reduce some age-related2.(disease).Whether it can do the same in people has been an open question. 3.  ,a new study suggests that in adults, long-term restriction of calorie intake can have an effect on their health.

The researchers looked at a group of 143 healthy adults who ranged in age4.21 to 50. They were instructed5.(practice)caloric restriction for two years.They could eat the foods they wanted so long as they cut back on the foods they ate,with the aim of6.(cut)the calories they consumed by 25 percent.

Many did not achieve that goal.On average,the dieters managed to cut down about 12 percent of their total calories, or7.(rough)300 calories a day. But the group saw many of their health markers improve. They8.(lose)body fat, their blood pressure fell slightly, and they had better blood sugar control. Meanwhile, another 75 healthy adults 9.  did not practice caloric restriction saw no 10.  (improve)in these markers.