Calories are a measure of energy in food. A small study has found that people improved their health when they severely restricted the amount of calories they ate. The study found that the people reduced their risk of heart attack, stroke and diabetes. Such risk normally increases with age.

卡路里是衡量食物能量的标准。一项小规模的研究发现，当人们严重限制了他们所吃的热量时，他们的健康状况会得到改善。研究发现，人们降低了患心脏病、中风和糖尿病的风险。这种风险通常随着年龄的增长而增加。

Researchers at the Washington University School of Medicine in Saint Louis, Missouri, led the study. They say lower risk of disease means that the people can expect to live longer than average lives. The results appeared in the Proceedings of the National Academy of Sciences.

位于密苏里州圣路易斯的华盛顿大学医学院的研究人员领导了这项研究。他们说，较低的疾病风险意味着人们可以活得比平均寿命长。研究结果发表在《美国国家科学院院刊》上。

Researchers compared people who ate a traditional Western diet with people who ate fewer calories. They found that those who restricted their calories had less chance of blocked arteries. Fatty material can block the flow of blood to the heart and brain, and cause a heart attack or stroke.

研究人员比较了那些吃传统西方饮食的人，他们吃的热量更少。他们发现，那些限制卡路里摄入的人动脉阻塞的几率更小。脂肪物质会阻碍血液流向心脏和大脑，导致心脏病或中风。

The researchers found the people for the study through an organization called the Caloric Restriction Optimal Nutrition Society. Members of this group try to eat between ten and twenty-five percent fewer calories than the average American.

研究人员通过一个名为“卡路里限制最优营养协会”的组织，找到了研究对象。这个群体的成员尝试吃的热量比一般美国人少10%到25%。

Eighteen members took part in the study. Their ages were thirty-five to eighty-two. They had lived on restricted calories for between three years and fifteen years. Doctors compared them with a group of people who ate normally.

18名成员参加了这项研究。他们的年龄是35岁到82岁。他们生活在限制卡路里的3年到15年之间。医生将他们与一组正常饮食的人进行比较。

The calorie-restricted group ate between one-thousand-one-hundred calories and about two-thousand calories per day. The amount depended on their weight, height and sex.

热量限制的人群每天摄入的热量在1000卡路里到2000卡路里之间。数量取决于他们的体重、身高和性别。

Twenty-six percent of the calories came from protein. Twenty-eight percent came from fat. And forty-six percent came from complex carbohydrates, such as whole grains.

26%的卡路里来自蛋白质。28%来自脂肪。而46%的人来自复杂的碳水化合物，如全谷物。

The other group ate between about two-thousand and three-thousand-five-hundred calories per day. Eighteen percent of their calories came from protein. Thirty-two percent came from fat. And fifty percent came from carbohydrates. These included processed sugars and grains.

另一组每天摄入的热量在2000到3000卡路里之间。其中18%的热量来自蛋白质。32%来自脂肪。其中50%来自碳水化合物。其中包括加工糖和谷物。

The researchers tested both groups for signs of blocked arteries. The team measured blood pressure and levels of several chemicals in the blood, including cholesterol and triglycerides. The doctors said some of the people who ate fewer calories had results like those of people many years younger.

研究人员对两组患者进行了动脉阻塞的检测。研究小组测量了血液中几种化学物质的血压和水平，包括胆固醇和甘油三酯。医生们说，一些摄入较少卡路里的人的结果与许多年小的人相似。