肥胖症与糖尿病有啥关系？溢出效应又是怎么一回事？

Original 脂肪多到爆棚啦蔬食益生

本视频由Michael Greger医生于2015年2月6日发布，来自NutritionFacts.org — 能救命的营养学。

如何从每年近10万篇营养领域论文中找出有价值的靠谱研究？

Michael Greger 医生是畅销书《How Not to Die》一书作者，中文译本：繁体版书名为《食疗圣经》。简体版书名为《救命》，将于今年5月出版。

编译者前言：Michael Greger 医生制作了三个糖尿病系列基础视频，第一个视频由于更新为动画演示版，所以发布日期比第二个视频还要晚。没有看过第一个视频的请补看一下。

糖尿病系列视频之一：动画演示”胰岛素抵抗”是如何发生的。

溢出效应将肥胖症与糖尿病联系起来

The Spillover Effect Links Obesity to Diabetes

摘要：肥胖可能会导致与吃高脂饮食一样多的胰岛素抵抗。

游离脂肪酸，意味着血液中循环的游离脂肪不会被包装成甘油三酯，会导致炎症，有毒的脂肪分解产物和氧化应激，这些脂肪酸会堵塞胰岛素受体通道并导致肌肉中的胰岛素抵抗。

Free fatty acids, meaning free fat circulating in the bloodstream not packaged into triglycerides, result in inflammation, toxic fat breakdown products, and oxidative stress, which can gum up the insulin receptor pathways and lead to insulin resistance in our muscles.

而胰岛素抵抗是导致糖尿病前期和2型糖尿病的原因。

And insulin resistance is what causes prediabetes and type 2 diabetes.

随着血液中脂肪水平的增高，人体从血液中清除糖分的能力也随之降低。

As the level of fat in the blood rises, the body’s ability to clear sugar from the blood drops.

血液中的这种破坏性极大的脂肪来自哪里呢？它来自我们所吃的脂肪，以及身体里的脂肪。

Where does this fat in our blood that’s wreaking all this havoc come from? It comes from the fat that we eat, and from the fat that we wear.

我们所拥有的脂肪细胞数量在成年期保持不变。

The number of fat cells we have stays constant in adulthood.

这真有趣；弄清楚这个的方法是通过测量所有核弹试验被捕获在DNA中的放射性碳的数量。

It’s interesting; the way they figured that out is by measuring the amount of radioactive carbon trapped in our DNA from all the nuclear bomb tests.

无论如何，大量减肥后，脂肪细胞在减脂时会缩小，但数量保持不变。

Anyway, after massive weight loss, our fat cells shrink as they offload fat, but the number stays the same.

反过来，当体重增加时，当我们把越来越多的脂肪放进每个脂肪细胞中，脂肪细胞就会变大。

Conversely, when we gain weight, our fat cells just stretch as we pack more and more fat into each individual fat cell.

所以当我们的腹部，臀部或大腿变大时，脂肪细胞不会增加；只是在每个细胞中增加了更多的脂肪。

So when our belly, butt, or thighs get big, we’re not adding more fat cells; we’re just cramming more fat into each cell.

到某个时候，脂肪细胞变得过于臃肿，以至于其中的脂肪溢出回到血液中。

At a certain point, our cells become so bloated that they spill fat back into the bloodstream.

这是所谓的溢出效应的例证。

This is an illustration of the so-called spillover effect.

肥胖的人不仅身体上会有更多的脂肪，而且还会不断地将脂肪洒入血液中。

Not only does an obese person have more fat on their body, but they’re constantly spilling that fat into their bloodstream.

这可能是肥胖和糖尿病之间的联系。

So that could be the link between obesity and diabetes.

脂肪会从脂肪细胞中溢出，并滞留在肌肉细胞中，导致胰岛素抵抗，进而促进2型糖尿病发作。

Fat is spilling out from our fat cells and gets lodged in our muscle cells, leading to the insulin resistance that promotes the onset of type 2 diabetes.

或者脂肪可以通过所吃的食物进入血液。

Or the fat can enter our bloodstream through our mouth.

低碳（高脂）饮食中的脂肪会在两小时内累积在肌肉中，与低脂饮食相比，胰岛素敏感性下降。

If you put people on a low-carb diet, fat builds up in their muscles within two hours, compared to a low-fat diet, and insulin sensitivity drops.

而肌肉中的脂肪越多，从血液中清除糖的能力就越低。

And the more fat in the muscle, the lower the ability to clear sugar from the blood.

这并不需要几年的时间，在吃下高脂肪食物后数小时，身体就有使用胰岛素的问题。

It doesn’t take years for this to happen; just hours after fatty foods go into our mouths, our bodies have problems using insulin.

高脂饮食可以增加血液中的脂肪，而这种增加伴随着胰岛素敏感性的降低。

A fat-rich diet can increase fat in the blood, and this increase is accompanied by a decrease in insulin sensitivity.

研究清楚地表明，血液中的脂肪直接抑制了葡萄糖在肌肉中的转运和使用，这是血液中85％的葡萄糖清除的原因。

Studies clearly demonstrate that fat in the blood directly inhibits glucose transport and usage in our muscles, which is responsible for clearing about 85% of the glucose out of blood.

这些发现还表明营养的重要作用，特别是增加脂肪摄取，对胰岛素抵抗的形成所起的重要作用。

These findings also indicate an important role of nutrition, particularly increased consumption of fat, for the development of insulin resistance.

通常情况下，血液中任何时候都只有10到50微摩尔的游离脂肪，但是那些肥胖的人不断将脂肪泼洒到血液中。

Normally we have only 10 to 50 micromoles of free fat floating around in our bloodstream at any one time, but those who are obese are constantly spilling fat out into their bloodstream.

然而吃下一餐高脂饮食也可以达到同样的水平。

But we can reach those same levels in our blood eating a high-fat diet.

因此，一个吃低碳（高脂）饮食的瘦人，其血液中的脂肪水平可能与肥胖者相同。

So a skinny person eating a low carb diet can have the same level of fat in their blood as obese people do.

同样，肥胖就像整天都在吃一些可怕的培根和黄油，肥胖者都会不断地将脂肪泼洒到血液中，不论他们吃的是什么。

Similarly, being obese is like eating some horrible bacon-and-butter diet all day, because obese persons are constantly spilling fat into their bloodstream no matter what goes in their mouth.

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