Do Carbohydrates Turn To Sugar When Digested?

The carbohydrates in food are made of sugar molecules that are joined together in different ways, depending on the type of carbohydrate. The three main categories of carbs are simple sugars, starch and dietary fiber. When you digest carbohydrates, some of them are broken down into sugars that your body uses for energy, while the rest have other functions that benefit your health.

Simple Sugars

There are two different groups of simple sugars. Monosaccharides consist of one sugar molecule, either glucose, fructose or galactose, while disaccharides are composed of two monosaccharides bound together. The most familiar disaccharide is sucrose, which is the white sugar you bake with or put in your coffee -- this consists of a fructose molecule joined to a glucose molecule. You may have also heard of lactose, which is the sugar found naturally in milk. Lactose is glucose and galactose bonded together. The third disaccharide is maltose -- two glucose molecules bound to each other. Maltose is also called malt sugar. Simple sugars are found in other sweeteners like honey, maple syrup and corn syrup, as well as in fruits and vegetables.

Starch

Starch is found in many foods that come from plants and consists of numerous glucose molecules joined together. These groups may be in the form of long chains or more complex branching units. Grains, legumes and starchy vegetables like potatoes are all familiar sources of starch.

Digesting Sugars and Starch

When you digest any food, your body breaks it down into forms that it can absorb and use for fuel or other functions. Because simple sugars and starch are made of sugars, they are broken back down into those sugars after you eat them. Some of this breakdown begins in your mouth when your saliva mixes with food, but most of it occurs in the small intestine, where the food you've eaten mixes with enzymes your body produces. These enzymes break apart the disaccharides so that they are once again molecules of glucose, galactose or fructose. Enzymes also break the chains of glucose that make up starch. Once this breakdown is completed, your small intestine releases the sugars for your body to use for energy right away or store for later.

Dietary Fiber

The third type of carbohydrate, fiber, is also composed of long chains of simple sugars linked together, but they are joined in a way that can't be broken down by your digestive system. Some fiber passes through as part of a bowel movement. The rest is used as fuel by beneficial bacteria that live in your large intestine. These bacteria produce byproducts that contribute to the health of your digestive system. Even though you don't digest it, dietary fiber has numerous health benefits, including keeping your digestive tract running smoothly, lowering cholesterol levels, helping with blood sugar control and aiding weight control by helping you feel full longer. Foods high in fiber include whole grains, legumes, fruits, vegetables and nuts.

Considerations

Don't let the presence of sugars in carbohydrates scare you away. Glucose, which is the building block of starches, is your body's main source of energy and the preferred fuel for your brain. Carbs are an important part of a healthy diet when you choose nutritious sources like fruits, vegetables, whole grains, nuts and legumes.