Good carbs, bad carbs. Simple carbs, complex carbs. No-carb diets, high-carb diets.
It’s no wonder we’re all a little confused about carbohydrates. You either love ‘em or you hate ‘em. But does this food have to be so darn polarizing? Can we have our cake – er, carbs – and eat them, too?
Let’s take a look at what carbohydrates actually are, why the human body needs them, and why it just might be okay to include them in your diet.
What are carbohydrates?
Your body needs all three macronutrients to function properly. That doesn’t mean you need all three in equal amounts. But it does mean that each one has a specific role to play in supporting the body’s processes.
The role of carbohydrates in the body
When carbohydrates reach your digestive system, they are converted into a simple sugar called glucose. Then, the body burns this glucose to create heat, or energy, for all the cells throughout the body.
When oxygen is used to help convert carbohydrates to glucose, the byproduct is a special molecule called, adenosine triphosphate, or ATP.
ATP is like storage space for extra energy, and whenever the body’s cells need more energy, ATP releases it to them.
So, the main function of carbohydrates is to provide fuel, or energy, to the body.
Two carbohydrate categories
You might think all carbohydrates are the same, but there’s a bit more to it than that. There are two carbohydrate categories:
- Simple carbohydrates
- Complex carbohydrates
Each category is a bit different. So, let’s take a look at each one.
Simple carbohydrates are small-chain carbohydrates. Monosaccharides are one-sugar molecules, and two types of monosaccharides are glucose and fructose.
Then, there are disaccharides, which are two-sugar molecules, such as sucrose and lactose. Sucrose is made up of glucose and fructose. Lactose, on the other hand, is composed of galactose and glucose.
Here are food examples of these simple carbohydrates:
- Fructose is present in fruit
- Sucrose is present in cane sugar
- Lactose is present in milk
Just as there are small-chain carbohydrates, there are also long-chain carbs. All this means is that the carbohydrate is made up of three or more glucose molecules.
When you eat these complex sugars, the digestive system breaks them down into glucose so the body can use them for fuel.
Whole grains are a good dietary example of complex carbohydrates.
Even though there are simple carbohydrates and complex carbohydrates, they all have one thing in common: sugar.
At the end of the day, both simple and complex carbs are composed of sugars. Your body breaks down simple carbs more quickly, whereas the complex carbs take a little bit longer to break down.
So, let’s take a look at how the body breaks down both simple and complex carbohydrates, and the influence they have on the body.
Carbohydrates and blood sugar
You’ve probably heard of the glycemic index (GI), and that there are either high GI foods or low GI foods.
Here, we’ll discuss both simple carbohydrates and complex ones, and how they fit into this conversation about blood sugar and the glycemic index.
To begin, here’s what happens in the body when you consume carbohydrates:
- First, carbohydrates get broken down into sugars, that is, into glucose.
- These sugars enter the bloodstream.
- When blood sugar levels go up, the pancreas makes insulin.
- Insulin tells the cells to absorb the sugar and to either use it as energy or to store it for later.
- When cells absorb sugar in the blood, the blood sugar levels drop.
- When blood sugar levels drop, the liver will release sugar to make sure all the cells in the body have enough glucose to function properly.
As you can see, both the pancreas and the liver always interact to make sure the entire body is getting the glucose it needs.
But not all carbohydrates are the same. You’ll remember that there are both simple and complex carbohydrates, and how they affect blood sugar levels varies. That’s where the glycemic index comes in handy.
Glycemic index basics
Because simple carbohydrates are composed of one or two sugars, it doesn’t take very long for the body to break them down. This means the sugar gets released into the bloodstream quickly.
However, when blood sugar rises too quickly, and the pancreas increases insulin production, this can be negative for the body – especially if it happens over a long-term period.
In fact, if this is a chronic problem, it can increase the risk for both type II diabetes and heart disease.
In general, simple carbohydrate foods are high GI foods.
Foods that are high on the glycemic index (20 or higher) include:
- White rice
- White flour pasta
- Baked potato
- French fries
- Refined, processed breakfast cereals
- Sugar-sweetened beverages
- Candy bars
When you eat these foods, your blood sugar levels rise pretty high and your pancreas works hard to release insulin to make sure blood sugar levels go back to normal.
But what about complex carbs?
Complex carbohydrates, on the other hand, are made up of three or more sugar molecules, and these require longer digestion. Therefore, sugar is released into the bloodstream much more slowly.
In general, complex carbohydrate foods are low GI foods.
The following foods are low GI options (10 or below)
- Kidney and black beans
- Whole wheat, and other whole grains
If you’d like to check the glycemic index for your favorite foods, or foods you eat regularly, you can check their GI values through the Harvard Health Publishing database. Here, you can search foods and see how they affect blood sugar levels.
Here’s why processed carbs are “bad carbs”
The glycemic index is important to help you gauge how certain carbohydrates will impact your blood sugar levels. But apart from this technical system, you can also choose carbohydrates wisely when you look for whole, unprocessed foods rather than processed and refined foods.
Whole and unprocessed forms of carbohydrates are sources not only of sugar but also of fiber, vitamins, minerals and other nutrients. All in all, it’s a higher quality food.
Processed carbs offer less nutritional value since the fiber and nutritional content is often stripped away. This means sugar can break down much more quickly, leaving us vulnerable to spikes in blood sugar levels.
Refined carbs include white flours, white rice, white pasta, sugary beverages and baked goods. While these are all common staples and all-time favorites, they’re also what you would call “bad” carbs, and for good reason.
They offer little to no nutritional value, and instead, are loaded with lots of sugar.
Recommended daily intake of carbohydrates
Since every cell in your body needs glucose, it’s important to eat carbohydrates as part of a balanced diet. However, what’s the magic number? How can you be sure you’re not eating too much or too little?
The truth is, there’s no easy answer. That’s because depending on your age, sex, physical activity levels and other factors, your carbohydrate needs will vary from the next person.
However, a good place to start is the Dietary Guidelines for Americans, which recommends that 45 and 65 percent of your daily calories should come from carbs. That comes to about 225 to 325 grams of carbohydrates per day.
So, what does that look like in real food terms?
A half cup of cooked oats is about 14 grams of carbs, and one cup of sliced strawberries is about 12 grams of carbohydrates.
To give you a better idea, you can always check the nutrition label on food packaging to help you see how many carbs are in your meals.
Your body needs carbohydrates
Carbohydrates get a bad rap, but the truth is, your body needs them. Just be sure that you consume whole food sources of carbohydrates. What’s more, look for complex carbohydrates that break down more slowly so your blood sugar levels don’t skyrocket.
Finally, remember that everybody is different. Some people need more carbs, while others can get away with less. One way to figure out how many carbs you need is to pay attention to how your body responds to the carbs you’re eating.
Working with a health coach and/or dietician can also help you determine what your own body needs when it comes to carbohydrates.
The bottom line is that you don’t have to be afraid of carbohydrates. They’re one of the three macronutrients that support a strong and healthy body.