Key Facts to Know About Carbohydrates
By: Woheema Parasram, MS RDN
In order to choose healthy carbohydrates, it's important to understand the different types of carbs. Here are some key things to know.
What are Carbohydrates?
Carbohydrates are a type of macronutrient that provides your body with the energy it needs to function optimally. These essential nutrients are naturally found in the fruit, vegetable, grain, and dairy food groups. Carbohydrates are also found in sweeteners such as sugar, honey, and agave and processed foods like cakes, candies, cookies, and soda. (1)
Three Main Types of Carbohydrates
The three main types of carbohydrates are:
Complex vs. Simple Carbs
Fiber and starch are classified as complex carbohydrates, whereas sugar is a simple carbohydrate. The main differences between complex and simple carbohydrates are their chemical composition and how they are metabolized by the body.
It is less likely that complex carbohydrates will cause a spike in blood sugar, and they usually contain vitamins, minerals, and fiber, which is beneficial to your overall health.
Simple sugars, on the other hand, tend to cause spikes in blood sugar, and excess consumption can lead to weight gain and increase your risk of diabetes, heart disease, and high cholesterol. While people tend to lump all carbohydrates together in one category, it is important to remember that they have very different effects on the body. (2)
Essential Carbohydrate Functions
One of the essential uses of carbohydrates in the body is to fuel brain activity. Carbs are broken down into glucose which is the brain's primary energy source. Studies have shown that removing carbohydrates from the diet can impair memory and cognitive function. (6)
Even though carbohydrates provide your body with energy, vitamins, minerals, and other important nutrients, they tend to have a bad reputation. This is because sugars and starches break down into simple sugars during the digestive process.
How Your Body Metabolizes Carbohydrates
These simple sugars get absorbed into the bloodstream, raising blood glucose (blood sugar) levels— before being transported into cells for utilization. Excessive consumption of simple sugars can lead to high blood sugar, also known as hyperglycemia, increasing your risk of developing type 2 diabetes and other chronic diseases.
Once glucose is taken inside the cells, these sugars can be used to fuel all of your body’s activities, whether that’s something active like running a marathon or passive activities such as breathing or blinking. Any extra glucose that is not used by the body right away gets stored in places like the liver or muscle for later use or it is converted to fat. (2)(3)
The amount of carbohydrates you should be eating depends on many factors such as your age, sex, and activity level. (4) The Dietary Guidelines for Americans recommend that 45-65% of your total daily calories come from carbohydrates. (3)
Quality Over Quantity
When considering which carbs to include in your diet, it’s important to remember that some carbs are healthier than others. While certain diets might suggest you “cut carbs” or decrease your consumption of carbohydrates, it’s ideal to focus on the quality of carbs you’re eating more than the quantity.
Fiber and starches are known as complex carbohydrates which are digested slower, less processed, and more nutrient-dense. Sugars, or simple carbohydrates, are digested more quickly, leading to a rapid rise in blood sugar, and they are usually added to processed foods in the form of refined sugars and processed sweeteners or syrups. (4)
Fiber is a complex carbohydrate that your body is unable to break down, and it is essential for the optimal health of your digestive tract. Fiber can help to stimulate digestion, promote regularity and prevent or alleviate intestinal issues such as constipation. It can also reduce your risk of developing chronic diseases by lowering cholesterol, keeping blood sugars stable, and preventing excessive weight gain by increasing satiation with fewer calories.
Daily Fiber Recommendations
It is recommended that women and men under 50 consume 25g and 38g of fiber a day, respectively. For women and men over 50, they should consume 21g and 30g of fiber a day, respectively. Unfortunately, on average, American adults only consume about 10-15 grams of fiber daily. (1)(2)(3)(4)(7)
Carbs To Limit in the Diet
While carbohydrates are a vital part of a healthy balanced diet, it is beneficial to limit the amount of added sugar and refined foods you consume. Unlike naturally occurring sugars which are usually packaged with vitamins, minerals, and fiber, added sugars are typically devoid of any nutrients.
Also, foods with added sugars tend to be higher in calories which can lead to unintended weight gain. (2) Foods that contain mostly simple carbohydrates include:
and other highly processed and refined foods
Recommended Limits for Daily Added Sugar
The American Heart Association recommends that women and men should consume no more than six teaspoons (25 grams) and nine teaspoons (36 grams) of sugar per day, respectively. Unfortunately, the average American adult consumes about 77 grams of sugar per day which adds up to about 60 pounds of added sugar per year!
Don’t see the word “sugar” in a product’s ingredients list but notice the item has a high sugar content? Well, nowadays, sugar goes by many names. You can see it listed in the ingredients list under other names such as agave nectar, high fructose corn syrup, cane syrup, corn syrup solids, dextrose, fructose, sucrose, honey, or molasses—to name a few! (2)
Carbs to Include Each Day
Ideally, we want to aim for a dietary pattern that is rich in complex carbohydrates such as starches and fiber, whole grains, fruits, vegetables, and low-fat dairy. (3)
Healthy carbohydrate-rich foods include:
Whole grain options include whole-wheat bread, brown rice, buckwheat, amaranth, whole grain pastas, rye, oatmeal, barely, and quinoa since they contain more amounts of fiber and important nutrients such as B vitamins.
Whole fruits and vegetables, not juices, contain more fiber and less sugar per serving. Fresh, frozen, and canned fruits and vegetables are great options, but be sure to check if there is any added sugar or salt in the product. (5)
Low-fat dairy includes skim, 1% or 2% milk, low-fat cheeses, and low-fat Greek yogurt. When choosing low-fat dairy options, be sure to check the nutrition facts panel for the amount of added sugar since it can be much higher than the full-fat version.
Protein-packed beans instead of French fries as your starch option. Beans and other legumes like chickpeas, black-eyed peas, soybeans, and lentils provide more protein and fiber along with more nutrients such as iron, folate, potassium, and magnesium. Beans and legumes are also a great substitute for meat which tends to be higher in saturated fat and cholesterol- things we should be limiting in our diet. (3)(5)
Carbohydrate Needs for Exercise
Carbohydrates are a key component of a successful nutrition plan for exercise. Take a look at recommended carbohydrate amounts for different lengths of exercise.
Important Nutrients to Know: Proteins, Carbohydrates, and Fats. National Institute on Aging. Accessed December 1, 2021. http://www.nia.nih.gov/health/important-nutrients-know-proteins-carbohydrates-and-fats
Carbohydrates: Types & Health Benefits. Cleveland Clinic. Accessed December 1, 2021. https://my.clevelandclinic.org/health/articles/15416-carbohydrates
Choose your carbs wisely. Mayo Clinic. Accessed December 1, 2021. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/carbohydrates/art-20045705
How many carbs should I eat a day? Published July 26, 2017. Accessed December 1, 2021. https://www.medicalnewstoday.com/articles/318617
Boston 677 Huntington Avenue, Ma 02115 +1495-1000. Carbohydrates. The Nutrition Source. Published September 18, 2012. Accessed December 1, 2021. https://www.hsph.harvard.edu/nutritionsource/carbohydrates/
Boyles S. No-Carb Diets May Impair Memory. WebMD. Accessed December 9, 2021. https://www.webmd.com/diet/news/20081212/no-carb-diets-may-impair-memory
LDN KDM MS, RD. Should I be eating more fiber? Harvard Health. Published February 21, 2019. Accessed December 9, 2021. https://www.health.harvard.edu/blog/should-i-be-eating-more-fiber-2019022115927
How much sugar is too much? www.heart.org. Accessed December 9, 2021. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/sugar/how-much-sugar-is-too-much