英语的速读和精读（24双语科普）

We hear about calories all the time. How many calories are in this cookie?

我们时常听到卡路里这个词。人们常常会问：这块饼干有多少卡路里？

How many are burned by 100 jumping jacks（开合跳）, or long distance running, or fidgeting?

做100下开合跳、长跑、或是动动身体可以燃烧多少卡路里？

But what is a calorie, really, and how many of them do we actually need?

但到底什么才是卡路里？我们到底需要多少卡路里？

Calories are a way of keeping track of the body's energy budget.

卡路里是一种追踪身体热量消耗与摄取的方式。

A healthy balance occurs when we put in about as much energy as we lose.

当我们摄取的卡路里与我们消耗掉的量相同时，身体就达到平衡。

If we consistently put more energy into our bodies than we burn, the excess will gradually be stored as fat in our cells, and we'll gain weight.

如果我们长时间摄入过量的热量，则会变成脂肪储存在我们的细胞里，我们的体重也会因此增加。

If we burn off more energy than we replenish（补充）, we'll lose weight.

如果我们消耗的热量大于摄取的量，我们就会变瘦。

So we have to be able to measure the energy we consume and use, and we do so with a unit called the calorie.

所以，我们必须知道如何计算我们摄取和消耗的热量，于是，我们用一个叫做卡路里的单位来计算。

One calorie, the kind we measure in food, also called a large calorie, is defined as the amount of energy it would take to raise the temperature of one kilogram of water by one degree Celsius.

卡路里是我们用来计算食物热量的单位，也称一大卡，其定义是可以将一公斤的水加热一摄氏度的热量。

Everything we consume has a calorie count, a measure of how much energy the item stores in its chemical bonds（化学键）.

而我们所吃的每样东西都有它的卡路里总量，可以让我们知道食物的化学键中储存了多少热量。

The average pizza slice has 272 calories, there are about 78 in a piece of bread, and an apple has about 52.

普通一片披萨有272卡的热量，一片面包大约有78卡的热量，而一颗苹果大约有52卡的热量。

That energy is released during digestion, and stored in other molecules（分子） that can be broken down to provide energy when the body needs it.

这些热量会在消化中释放出来，接着被储存在其它分子中，而这些分子会被分解以提供身体所需的能量。

It's used in three ways: about 10% enables digestion, about 20% fuels physical activity, and the biggest chunk, around 70%, supports the basic functions of our organs and tissues（组织）.

这些能量用于三个地方：约10%被用来进行消化作用，约20%运作身体的各项活动，而最大的部分，约70%的能量负责支撑我们身体器官或组织的功能运作。

That third usage corresponds（与...相关） to your basal metabolic rate, a number of calories you would need to survive if you weren't eating or moving around.

第三个与你的基础代谢率有关，也即在不动不吃的状态下，你的身体需要消耗的基本热量。