How do carbohydrates impact your health Richard J. Wood

Which of these has
the least carbohydrates?

This roll of bread?

This bowl of rice?

Or this can of soda?

It’s a trick question.

Although they may differ in fats,
vitamins, and other nutritional content,

when it comes to carbs,
they’re pretty much the same.

So what exactly does that mean
for your diet?

First of all, carbohydrate is
the nutritional category for sugars

and molecules that your body breaks down
to make sugars.

Carbohydrates can be simple or complex
depending on their structure.

This is a simple sugar,
or monosaccharide.

Glucose, fructose,
and galactose are all simple sugars.

Link two of them together,
and you’ve got a disaccharide,

lactose, maltose, or sucrose.

Complex carbohydrates,
on the other hand,

have three or more simple sugars
strung together.

Complex carbohydrates with three
to ten linked sugars

are oligosaccharides.

Those with more than ten
are polysaccharides.

During digestion,

your body breaks down those
complex carbohydrates

into their monosaccharide building blocks,

which your cells can use for energy.

So when you eat
any carbohydrate-rich food,

the sugar level in your blood,
normally about a teaspoon, goes up.

But your digestive tract doesn’t respond
to all carbohydrates the same.

Consider starch and fiber,

both polysaccharides,

both derived from plants,

both composed of hundreds to thousands
of monosaccharides joined together,

but they’re joined together differently,

and that changes the effect
they have on your body.

In starches, which plants mostly store
for energy in roots and seeds,

glucose molecules are joined together
by alpha linkages,

most of which can be easily cleaved
by enzymes in your digestive tract.

But in fiber, the bonds between
monosaccharide molecules are beta bonds,

which your body can’t break down.

Fiber can also trap some starches,
preventing them from being cleaved,

resulting in something called
resistant starch.

So foods high in starch,
like crackers and white bread,

are digested easily,

quickly releasing a whole bunch of glucose
into your blood,

exactly what would happen if you drank
something high in glucose, like soda.

These foods have a high glycemic index,

the amount that a particular food
raises the sugar level in your blood.

Soda and white bread have a similar
glycemic index

because they have a similar effect
on your blood sugar.

But when you eat foods high in fiber,
like vegetables, fruits, and whole grains,

those indigestible beta bonds slow
the release of glucose into the blood.

Those foods have a lower glycemic index,

and foods like eggs, cheese, and meats
have the lowest glycemic index.

When sugar moves from the digestive tract
to the blood stream,

your body kicks into action to transfer it
into your tissues

where it can be processed
and used for energy.

Insulin, a hormone
synthesized in the pancreas,

is one of the body’s main tools
for sugar management.

When you eat and your blood sugar rises,

insulin is secreted into the blood.

It prompts your muscle and fat cells
to let glucose in

and jump starts the conversion
of sugar to energy.

The degree to which a unit
of insulin lowers the blood sugar

helps us understand something called
insulin sensitivity.

The more a given unit of insulin
lowers blood sugar,

the more sensitive you are to insulin.

If insulin sensitivity goes down,
that’s known as insulin resistance.

The pancreas still sends out insulin,

but cells, especially muscle cells,
are less and less responsive to it,

so blood sugar fails to decrease,

and blood insulin continues to rise.

Chronically consuming
a lot of carbohydrates

may lead to insulin resistance,

and many scientists believe
that insulin resistance

leads to a serious condition
called metabolic syndrome.

That involves a constellation of symptoms,

including high blood sugar,

increased waist circumference,

and high blood pressure.

It increases the risk
of developing conditions,

like cardiovascular disease

and type II diabetes.

And its prevalence is rapidly increasing
all over the world.

As much as 32% of the population
in the U.S. has metabolic syndrome.

So let’s get back to your diet.

Whether your food tastes sweet or not,
sugar is sugar,

and too many carbs can be a problem.

So maybe you’ll want to take a pass

on that pasta sushi roll pita burrito
donut burger sandwich.

其中哪个
碳水化合物最少?

这卷面包?

这碗饭?

还是这罐汽水?

这是一个技巧问题。

尽管它们在脂肪、
维生素和其他营养成分方面可能不同

,但在碳水化合物方面,
它们几乎相同。

那么这
对你的饮食究竟意味着什么?

首先,碳水化合物是
糖和分子的营养类别

,您的身体会分解这些分子
来制造糖。

碳水化合物可以是简单的也可以是复杂的,
这取决于它们的结构。

这是一种简单的糖
或单糖。

葡萄糖、果糖
和半乳糖都是单糖。

将它们中的两个连接在一起
,您就得到了二糖、

乳糖、麦芽糖或蔗糖。 另一方面

,复合碳水化合物

含有三种或三种以上的单糖
串在一起。

具有三
到十个连接糖的复合碳水化合物

是寡糖。

超过十个的
是多糖。

在消化过程中,

您的身体会将这些
复杂的碳水化合物

分解成它们的单糖构件

,您的细胞可以将其用作能量。

因此,当你吃
任何富含碳水化合物的食物时,

血液中的糖含量(
通常约为一茶匙)会上升。

但是你的消化道
对所有碳水化合物的反应并不相同。

考虑一下淀粉和纤维,

这两种多糖

都来自植物,

都由成百上千
的单糖组成,

但它们的结合方式不同

,这会改变
它们对您身体的影响。

在淀粉中,植物主要
将能量储存在根和种子中,

葡萄糖分子
通过α键连接在一起,

其中大部分很容易被
消化道中的酶切割。

但在纤维中,
单糖分子之间的键是 β 键

,你的身体无法分解。

纤维还可以捕获一些淀粉,
防止它们被切割,

从而产生一种叫做
抗性淀粉的东西。

所以淀粉含量高的食物,
比如饼干和白面包,

很容易被消化,

很快就会把一大堆葡萄糖释放
到你的血液中,

如果你喝了
一些高葡萄糖的东西,比如苏打水,会发生什么。

这些食物具有高血糖指数

,即特定食物
会提高血液中糖含量的量。

苏打水和白面包的血糖指数相似,

因为它们对血糖的影响相似

但是当你吃富含纤维的食物时,
比如蔬菜、水果和全谷物,

那些难以消化的 β 键会
减缓葡萄糖释放到血液中的速度。

这些食物的升糖指数较低,

而鸡蛋、奶酪和肉类等食物
的升糖指数最低。

当糖从消化道
转移到血液中时,

您的身体就会开始行动,将其转移
到您的组织中

,在那里它可以被加工
并用作能量。

胰岛素是一种
在胰腺中合成的激素,

是人体控制糖分的主要
工具之一。

当你吃东西并且你的血糖升高时,

胰岛素会分泌到血液中。

它会促使你的肌肉和脂肪
细胞让葡萄糖

进入并开始将
糖转化为能量。

一个单位
的胰岛素降低血糖的程度

有助于我们理解一种叫做
胰岛素敏感性的东西。

给定单位的胰岛素越能
降低血糖

,您对胰岛素就越敏感。

如果胰岛素敏感性下降,
这就是所谓的胰岛素抵抗。

胰腺仍然会发出胰岛素,

但细胞,尤其是肌肉细胞,
对它的反应越来越差,

所以血糖没有下降

,血胰岛素继续升高。

长期
摄入大量碳水化合物

可能会导致胰岛素抵抗

,许多科学家
认为胰岛素抵抗

会导致一种
称为代谢综合征的严重疾病。

这涉及一系列症状,

包括高血糖、

腰围增加

和高血压。

它会增加患

心血管疾病

和 II 型糖尿病等疾病的风险。

它的流行在全世界范围内迅速增加

美国多达 32% 的
人口患有代谢综合征。

所以让我们回到你的饮食。

不管你的食物尝起来甜不甜,
糖就是糖

,过多的碳水化合物可能是个问题。

所以,也许你会想

尝尝那个意大利面寿司卷皮塔卷饼
甜甜圈汉堡三明治。