(单词翻译:单击)
There are some things in life that when they're around, we wish they weren't there and when they're gone, we're just glad that they left.
总有一些东西，当它们在我们身边时，我们不想要，而当它们真的消失时，我们也特别开心。
For many of us, one of those things is fat.
对大多数人而言，脂肪就是其中之一。
But your fat tissue is full of important biological molecules called lipids -
但是你的脂肪组织都是由被称为脂类的重要生物分子组成，例如 -
long and stringy compounds of hydrogen, carbon and oxygen that are great at storing energy in their chemical bonds.
长纤维氢、碳和氧化合物，这些分子都善于在它们的化学键内储存能量。
When the molecules are broken apart, they release the energy stored in their bonds.
当分子分裂时，它们会释放存在化学键内的能量。
We often refer to this process as: burning fat.
通常我们将这一过程称为：燃烧脂肪。
But when you burning fat, where does that material - the actual stuff that jiggles around and cushions you and insulates you - where does it go?
但是当你在燃烧脂肪的时候，那些物质--那些在你体内左右晃动、震动，与你相隔的真实物质--它们到哪去了呢？
Interestingly enough, a recent survey of doctors, dieticians and physical trainers revealed that even the experts in fat loss didn't know the answer. Although they thought they did.
有趣的是，一份对医生、营养师及体能教练的调查发现，即使是减脂专家也无法给出答案。虽然，他们都认为他们知道答案。
More than 50% of the respondents thought that when you burn fat, all that mass is simply converted into energy and lost as heat.
超过50%的调查对象认为当你在燃烧脂肪的时候，所有物质质量都会转化成能量并以热量的形式排出体外。
It's a common misconception, but it's not possible.
这是一种常见的错误想法，并不可信。
I mean just because you don't like something doesn't mean that the laws of chemistry don't apply to it
我是说你不喜欢某种东西并不意味着化学定律对其不适用。
and one of the basic principles of chemistry is the conservation of mass.
化学基本原理之一就是质量守恒。
This just means that the same amount of material always comes out of a reaction as goes into it.
这个原理是指物质总和与参加反应的物质的物质总相同。
Even if that reaction happens to generate heat, you'll wind up with the same number of each kind of atom that you started with.
即使这种化学反应是产生热量，最终你得到的每种分子量也和开始时一样。
So, when you break up those lipids in your fat cells and release their energy, all of that hydrogen, carbon, and oxygen in those molecules will still be there afterward.
因此，当你分解脂肪细胞中的脂类并释放它们的能量时，所有分子中的氢、碳和氧依然存在。
But if you burn a lot of fat, and it's not there anymore to hold your pants up or whatever, where did the mass go? Turns out, you exhaled it.
但是如果你燃烧了大量脂肪，脂肪则不再存在，那么它们去哪了呢？结果是，你将它们排出去了。
Biologists at the University of New South Wales recently did an atom by atom breakdown of where the mass of your fat goes after it's burned in your body.
近日，新南威尔士的生物学家们对大量脂肪燃烧后的去向进行逐个原子分解。
They found that for ever ten kilograms of fat that you burn, you have to inhale 29 kilograms of oygen to metabolize or break down the fat and release its energy.
他们发现即使燃烧10千克的脂肪，你也会吸入29千克的氧用于新陈代谢或脂肪分解并释放能量。
And the process of breaking down that much fat produces 28 kilograms of carbon dioxide and 11 kilograms of water.
而这些脂肪的分解会产生28千克的二氧化碳和11千克的水。
So for every kilo of fat that you burn in your body, more than 80% of that mass is lost as carbon dioxide that you breathe out.
因此，你在身体内燃烧的每一千克脂肪，超过80%的质量会通过吸入二氧化碳的形式排出。
The other 20% you lose as water in your urine or sweat, or depending how hard you work out, your tears.
剩余的20%会通过尿液或汗的形式排出，或取决于你锻炼的强度，通过你的眼泪排出。
But if you do the math, you will see that all the mass in that fat-burning reaction has been conserved.
如果认真算算，会发现所有脂肪燃烧反应的质量都已被保存。
10 kilos of fat plus 29 kilos of oxygen equals 39 kilos total. And together they produce 28 kilos of CO2 plus 11 of water which also equals 39 kilos.
10千克的脂肪加上29千克的氧等于39千克。它们共同产生28千克的二氧化碳加上11千克的水，结果也是39千克。
So remember that the next time you're huffing and sweating on a treadmill, or walking your dog, or really doing anything that makes your body call on its energy reserves,
所以，下一次，当你在跑步机上挥汗如雨时、或是在遛狗或做一些需要能量保存的事时，
you're basically just emanating fat through your breath and your skin, but in a good way.
你基本上是通过呼吸和你的皮肤流出脂肪，但这是一种好的方式。
Thanks for asking and thanks especially to our Subbale subscribers who keep these answers coming.
谢谢你们的提问，特别感谢Subbale订阅者。
If you have a quick question let us know on Facebook, Twitter, Tumblr or in the comments below, and don't forget to go to youtube.com/scishow and subscribe.
如果你有任何问题，欢迎登陆Facebook, Twitter, Tumblr对我们提问或者在下方留言，不要忘记去youtube.com/scishow订阅我们。
