Introduction to Carbohydrates

If someone says to you, "I love carbohydrates, and I eat them all day long!" what would you assume they're eating?

Do you picture this?

close-up photograph of potato chips Photo of pile of M&M candies close-up photo of a pastry dusted with powdered sugar

Fig. 1.1. Examples of carbohydrate-rich snack foods.

And this?

photo of a pile of bread, as in a bakery photo of a serving of spaghetti with a little tomato sauce, on a plate bowl of white rice

Fig. 1.2. Examples of grain-based foods.

When we ask this question in class, most students describe foods like the ones above. However, carbohydrates are found not just in grains, or in sweets and processed foods, but in every food group. In fact, carbohydrates are the most abundant nutrient (except water) in the diets of most humans around the world. Since the dawn of agriculture, human cultures have relied on staple grains, such as corn, rice, and wheat, as the foundation of their diets, and these foods are rich in carbohydrates. But fruits and vegetables, dairy products, legumes, and nuts also have naturally-occurring carbohydrates. And of course, carbohydrates are a key ingredient in desserts, sugar-sweetened beverages like sodas, and many of the packaged snack foods that are readily available and -- let's face it -- can be hard to stop eating. In other words, if someone says they eat a high carbohydrate diet, that could mean many different things. They very well could be talking about a balanced diet focused on whole foods, like this:

close-up of a bowl of fresh fruit, including apples, oranges, and peaches Photo showing several bowls and piles of uncooked beans and rice photo showing cubes of several kinds of cheese

Fig. 2.3. Examples of whole foods containing carbohydrates, including fresh fruit, legumes and grains, and cheese.

The diet industry likes to sell us simple messages about "good" and "bad" foods, and these days, we tend to hear that carbohydrates are in the "bad" group. But given that carbohydrates are in so many different types of foods, that's obviously an oversimplified message -- and it's not fair to all of the awesome sources of carbohydrates in the world of food. Not all carbohydrate-rich foods are the same. In this unit, you'll learn to appreciate the nutrient-dense carbohydrate foods, identify which don't offer as valuable a nutritional package, and understand how a balanced diet can include all of them.

Topics Covered in this Unit

  1. Types of carbohydrates

  2. Food sources of carbohydrates and guidelines for intake

  3. Digestion and absorption of carbohydrates

  4. Glucose utilization and regulation in the body

  5. Fiber: Benefits, recommendations, food sources, and whole vs. refined grains

  6. Sugar: Food sources, health Implications, intakes, and label-reading to identify sugar

  7. Sugar substitutes

Course Learning Outcomes Covered

  1. Define and classify the six classes of nutrients.

  2. Identify where the six classes of nutrients are found in foods.

  3. Explain how the six classes of nutrients are digested, absorbed, metabolized, and utilized.

  4. Distinguish between adequate nutrient intake, deficiencies, and toxicities and how these levels impact body systems and health outcomes.

  5. Acknowledge the importance of a moderate approach when it comes to nutrition and weight management, recognizing all foods can fit into a healthful diet.

  6. Critically evaluate and compare nutrition labels and determine the nutrient density of each food.

Image Credits

  1. Potato chips picture by Kate Ter Haar, CC BY 2.0,; M&Ms picture by Wade Brooks, CC BY-NC 2.0,; Pecan pastry picture by Artizone, CC BY-NC-ND 2.0,

  2. Bread picture by David Stewart, CC BY 2.0,; Pasta picture by Yasumari SASAKI, CC BY 2.0,; Rice photo by Francesca Nocella, CC BY-SA 2.0,

  3. Fruit picture by Allen Gottfried, CC BY-SA 2.0,;  Beans and grain picture by Evans E, CC BY 2.0,; Cheese picture by Finite Focus, CC BY-NC 2.0,

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