Your body uses sugar -- formally known as glucose -- as its primary source of energy. Your body receives glucose from the carbohydrate-containing foods and drinks that you consume. Carbohydrates are found in a variety of food items, including fruits, vegetables, legumes, grains, milk and soft drinks. Because you get glucose from carbohydrates, your blood sugar levels reflect the type and amount of carbohydrates in your diet and your body's ability to handle them.
Types of Carbohydrates
Carbohydrates include three distinct types: sugar, starch and fiber. Milk is an example of a food that contains naturally occurring sugar, while processed foods tend to contain added sugars such as high-fructose corn syrup, honey or molasses. Foods rich in starch include bread, pasta and other foods made from grains. Examples of fiber-rich carbohydrates include plant-based foods such as fruits, vegetables and legumes. Together, these three categories make up what is known as your total carbohydrate intake.
Glycemic Index
Not all carbohydrate-containing foods produce the same effect on your blood sugar levels. For example, your blood sugar will increase more after you eat a piece of chocolate cake than it will after you eat a piece of fresh fruit. The glycemic index measures the degree to which a carbohydrate-containing food is likely to raise your blood sugar. The glycemic index of a food is affected by the amount of carbohydrate and the type.
Blood Sugar Basics
After you eat a carbohydrate-containing food, your body begins to break it down through the process of digestion. Sugar and starch carbohydrates are converted into glucose and then absorbed into your bloodstream. Fiber is different. Fiber is not broken down into glucose. Instead, fiber passes through your body undigested. For this reason, carbohydrate-containing foods that contain a lot of fiber do not usually produce a significant effect on your blood sugar levels.
Insulin and Glucagon
Your blood sugar levels are regulated by two hormones called insulin and glucagon. When your blood sugar gets too high, your pancreas secretes insulin, which transports glucose from your bloodstream to your cells, where they can be used for energy. When your blood sugar gets too low, your pancreas secretes glucagons, which triggers your body to release the glucose stored in your liver and send it to your bloodstream. If you have insulin resistance, diabetes or pre-diabetes, your body has difficulty stabilizing its blood sugar levels on its own.
