Speaker 1: Welcome to Brainstuff from house Stuff works dot com where
Speaker 1: smart happens. Hi. I'm Marshall Brain with today's question, how
Speaker 1: do carbohydrates work and why do we hear about them
Speaker 1: all the time? In the news? Carbohydrates are something we
Speaker 1: hear about constantly in American culture. There are simple carbohydrates
Speaker 1: and complex carbohydrates, where complex carbohydrates are supposed to be
Speaker 1: better for your health than the simple ones. There are
Speaker 1: low carb diets like the Atkins diet or the Ducan diet,
Speaker 1: and they're supposed to help you lose lots of weight
Speaker 1: by somehow eliminating the bad effects of carbohydrates. Then there's
Speaker 1: the more esoteric things like the glycemic index of foods,
Speaker 1: and this has to do with carbohydrates as well. Let's
Speaker 1: take a look at how carbohydrates work and why you
Speaker 1: should care about them. You've probably heard of things like
Speaker 1: glucose and pctoes. These are the simplest carbohydrates. They are
Speaker 1: molecules containing six carbon atoms, six oxygen atoms, and twelve
Speaker 1: hydrogen atoms, and this is where the name carbohydrate comes from.
Speaker 1: Carbo represents the carbon atoms, while the oxygen and hydrogen
Speaker 1: atoms represent water or hydrates. Plants make carbohydrates from sunlight,
Speaker 1: and animals eat the plants. Pure glucose or pure fructose,
Speaker 1: being the simplest carbohydrates, can be immediately absorbed by the
Speaker 1: small intestine into the bloodstream. Table sugar or sucrose is
Speaker 1: a die sacc ride. One glucose and one fructose molecule
Speaker 1: are bonded together to make a molecule of sucrose. And
Speaker 1: enzyme in your small intestine can break the pair apart
Speaker 1: and then they can be immediately absorbed in your small
Speaker 1: intestine and they enter the bloodstream. A starch, like the
Speaker 1: starch found in wheat or potatoes or rice, is a
Speaker 1: longer chain of glucose molecules connected together. Your body has
Speaker 1: enzymes that can break apart the chain into individual glucose
Speaker 1: molecules for absorption. Starch molecules are known as complex carbohydrates,
Speaker 1: and this is where the idea of the glycemic index
Speaker 1: comes from. In general, things like glucose and table sugar
Speaker 1: come into your body and enter the bloodstream very very quickly.
Speaker 1: They have a high glycemic index and cause a spike
Speaker 1: in the amount of glucose in your bloodstream. White bread,
Speaker 1: because the wheat is so highly processed, also has a
Speaker 1: high glycemic index. Whole grains, beans, nuts, and vegetables do
Speaker 1: contain carbohydrates, but these carbohydrate chains take much longer to
Speaker 1: break down in the small intestine, so the glucose from
Speaker 1: these foods enters the bloodstream much more slowly and evenly.
Speaker 1: These foods have a low glycemic index and therefore are
Speaker 1: much healthier because they don't cause such intense spikes in
Speaker 1: blood sugar. Many diet it's are low carb diets. They
Speaker 1: ask you to restrict the carbohydrates you eat. Why do
Speaker 1: they do that? Keep in mind that what a typical
Speaker 1: American diet looks like is things like a bowl of
Speaker 1: cereal or a slice of pizza, or a can of ravioli,
Speaker 1: or a bottle of soda, potato chips, packages of cookies,
Speaker 1: bowls of ice cream. These are common foods in the
Speaker 1: typical American diet. These foods typically contain something like forty
Speaker 1: to fifty grams of carbohydrates per serving. Therefore, a typical
Speaker 1: American eating a typical American diet can easily consume three
Speaker 1: hundred grams of carbs per day or more without even
Speaker 1: thinking about it. A lunch consisting of two slices of pizza,
Speaker 1: chocolate chip cookie, and a big soda. That's two hundred
Speaker 1: grams of carbs right there, and it all comes in
Speaker 1: in just a few minutes. The surge of glucoast that
Speaker 1: a meal like this pumps into the bloodstream requires your
Speaker 1: body to use a lot of insulin to handle the spike.
Speaker 1: Over the years, the spikes can cause type two diabetes,
Speaker 1: where your body becomes resistant to the effects of the
Speaker 1: insulin that your pancreas is putting into the bloodstream. In addition,
Speaker 1: a meal like that contains a lot of calories, leading
Speaker 1: to obesity over time, and that causes its own set
Speaker 1: of health effects. A low carb diet restricts your carbohydrate intake,
Speaker 1: say fifty grams of carbs per day rather than three hundred.
Speaker 1: This restriction can decrease the spikes in blood sugar, which
Speaker 1: tends to lower hunger pangs and reduce the calories you
Speaker 1: consume per day. Will a low carb diet hurt you?
Speaker 1: For example, you may know that your brain and nervous
Speaker 1: system require glucose. If you take in no carbohydrates, will
Speaker 1: your brain die No. Your body, when necessary can manufacture
Speaker 1: its own carbohydrates in your liver through a process called
Speaker 1: gluco neogenesis. This process is important if say, you're lost
Speaker 1: in a forest with no food for three days, or
Speaker 1: if you're fasting for some reason, or if you get
Speaker 1: so sick that you can't eat for a few days,
Speaker 1: or if you're living in an extremely cold climate and
Speaker 1: meat is your only source of food. In all those cases,
Speaker 1: there's no glucose coming in, so obviously your body has
Speaker 1: to have a way to deal with it. Glucose is essential,
Speaker 1: so your body is able to supply the glucose even
Speaker 1: if you have no carbohydrates coming in through your food.
Speaker 1: This whole thing is fascinating really. Carbohydrates are one source
Speaker 1: of food energy, but there are all these different aspects
Speaker 1: to it, and carb consumption can have a huge impact
Speaker 1: on your overall health. The more you learn about carbohydrates,
Speaker 1: the more interesting it gets. For more on this and
Speaker 1: thousands of other topics, does that house stuff works dot
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