How many calories are in this cookie?

このクッキーのカロリーはどれくらいですか。

How many are burned by 100 jumping jacks, or long distance running, or fidgeting?

100回の挙手跳躍運動、長距離走、体をちょっと動かしたら、どれくらいのカロリーを消費するのでしょうか？

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

カロリーとは一体何なのでしょうか。私たちが必要とするカロリーはどれくらいなのでしょうか？

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

カロリーは体内エネルギーの計算方法の一つです。

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

摂取したエネルギーと消費したエネルギーが同じな場合、健康なバランスと言えます。

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.

もし摂取したエネルギーが消費したエネルギーより多かったら

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

超過分は脂肪として細胞に貯めることになります。

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

そして太るのです。

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.

代わりに、もし消費したエネルギーが摂取したエネルギーより多いなら、痩せます。

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

ですから、摂取エネルギーと消費エネルギーをどう測るか学ばなければなりません。

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

そして私たちはカロリーという単位で測ることにしました。

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

食べ物のエネルギーを測る単位がカロリーで、大カロリーとも言います。

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.

１カロリーとは

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

1キロの水の温度を１℃上げるのに必要なエネルギーです。

Add in some physical activity and digestion, and you arrive at the official guidelines for how many calories the average person requires each day:

私たちが食べたものはそれぞれカロリー含有量が違います。

2000 for women and 2500 for men.

その食べ物の化学結合はどのくらいのエネルギーがあるかを示すのです。

Those estimates are based on factors like average weight, physical activity and muscle mass.

一般的に、ピザ一切れは272カロリーです。

So does that mean everyone should shoot for around 2000 calories?

パン一切れは78カロリーです。

Not necessarily.

そして、リンゴ一つのカロリーは52カロリーです。

If you're doing an energy guzzling activity, like cycling the Tour de France, your body could use up to 9000 calories per day.

消化作用によって食べ物からエネルギーを得て分子に貯めるのです。

Pregnancy requires slightly more calories than usual, and elderly people typically have a slower metabolic rate, energy is burned more gradually, so less is needed.

これらの分子は分解され、体が必要なエネルギーを提供します。

Here's something else you should know before you start counting calories.

エネルギーの用途は三つあります。

The calorie counts on nutrition labels measure how much energy the food contains, not how much energy you can actually get out of it.

そのうちの10％は消化作用に使われおり、

Fibrous foods like celery and whole wheat take more energy to digest, so you'd actually wind up with less energy from a 100 calorie serving of celery than a 100 calorie serving of potato chips.

20%は身体活動を促進するのに使われています。

Not to mention the fact that some foods offer nutrients like protein and vitamins, while others provide far less nutritional value.

そして、ほどんとのエネルギー、約70％のエネルギーは、

Eating too many of those foods could leave you overweight and malnourished.

私たちの器官と組織の基本機能を維持するために使われているのです。

And even with the exact same food, different people might not get the same number of calories.

最後のはあなたの基礎代謝率と関係していて、

Variations in things like enzyme levels, gut bacteria, and even intestine length, means that every individual's ability to extract energy from food is a little different.

もしあなたが何もしなかったり、何も食べなかったとしても、必要な最低限のエネルギーです。

So a calorie is a useful energy measure, but to work out exactly how many of them each of us requires we need to factor in things like exercise, food type, and our body's ability to process energy.

それに加えて、身体活動と消化作用を一緒に測れば、

Good luck finding all of that on a nutrition label.

一日あたり必要なカロリーが