Complex Carbohydrates and Diabetes: The Basics

Why different types of carbs matter

A carbohyrate-rich breakfast. Stockbyte/Getty Images

Wondering what complex carbohydrates have to do with diabetes? The answer to that question requires a close look at the basics to learn exactly what a carbohydrate is.

Carbohydrates (often referred to as carbs for short) are one of the three main nutrients in our diet, the others being protein and fat. We need ample amounts of these three nutrients, especially carbohydrates because they are our main sources of energy.

Once foods that contain carbohydrates are consumed, your liver breaks down the carbs into glucose (sugar), which your body then uses for energy for virtually every task, from running to thinking.

Types of Carbs

The body uses two types of carbohydrates (sugar and starch) for energy, while a third type of carbohydrate (fiber) is used to keep the digestive tract healthy. They two carbohydrates used for energy are classified into simple or complex, depending on how quickly your body absorbs the sugar. Simple sugars are absorbed more quickly by the body than complex carbohydrates, and therefore cause your blood sugar to rise more quickly than complex carbs. Complex carbs contain starch, which takes longer to digest before the glucose can be used for energy. Foods with simple sugars also usually have a higher rank in the Glycemic Index; a helpful tool for gauging the amount of glucose in foods.

Simple Carbohydrates

Simple carbohydrates (also called simple sugars), are found in foods such as vegetables (such as carrots and beets), fruits and fruit juice concentrate, soda, milk products, sugary breakfast cereals, packaged cookies, candy, table sugar, brown sugar, corn syrup, honey and other refined sugars.

According to the American Diabetes Association, the following simple carbs contain about 15 grams of carbohydrates:

  • 1 small piece of fresh fruit (4 oz)
  • 1/2 cup of canned or frozen fruit
  • 2 small cookies
  • 2 inch square brownie or cake without frosting
  • 1/2 cup ice cream or sherbet
  • 1 Tbsp syrup, jam, jelly, sugar or honey
  • 2 Tbsp light syrup
  • 2/3 cup of plain fat-free yogurt

Complex Carbohydrates

Complex carbohydrates (also called starches) are found in whole grain breads, pasta, rice, quinoa, corn, potatoes, vegetables (such as broccoli and kale), cereals, oats, nuts and legumes (peas, dry beans, etc.)

According to the American Diabetes Association, the following complex carbs contain about 15 grams of carbohydrates:

  • 1 slice of bread (1 oz) or 1 (6 inch) tortilla
  • 1 cup of soup
  • 1/2 cup of oatmeal
  • 1/3 cup of pasta or rice
  • 1/2 English muffin or hamburger bun
  • 1/4 serving of a medium french fry
  • 1/2 cup of black beans or starchy vegetable
  • 1/4 of a large baked potato (3 oz)

Complex Carbohydrates and Diabetes

Though many foods contain carbohydrates, the challenge for those with diabetes is to choose nutritious options to help control blood sugar levels. Even though simple sugars raise your blood sugar more quickly than complex carbohydrates, one carb is not necessarily better than the other and both should be made a part of your daily meal plan.

However, complex carbohydrates are ideal for people with diabetes as they can better help manage blood sugar spikes after meals. This is because complex carbs are higher in fiber and digest more slowly so they pack in more nutrients than simple carbs do — as a result, complex carbs are also more filling and help to control overeating.


Carbohydrates. Centers for Disease and Control. Accessed June 7, 2009. ​

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