You'll get some type of carbohydrates from nearly all foods in your diet. Carbohydrates are important for two distinct functions: energy and digestion. Some carbohydrates break down quickly for immediate energy, while others take awhile, giving you sustained energy. Other types of carbohydrates do not break down at all and keep your bowels moving during digestive processes.
Carbohydrates can be either simple or complex. Simple carbohydrates are small compounds, known as sugars, that break down rather quickly in your small intestine. Complex carbs, or starches, are large-branched molecules that undergo several steps during digestion. Eventually, both sugars and starches convert into glucose, which is the primary energy source for all cells and the only type of fuel that brain cells can use. Since sugars digest rapidly, you may feel a sugar rush or short burst of energy immediately after consuming a sugar-rich foods. Because starches take longer to convert into glucose, they tend act like a time-release energy capsule, keeping your energy levels stable.
Fiber is a type of complex carbohydrate, but it is different in the sense that it is not broken down and does not transform into glucose. Instead, fiber stays intact for the most part and aids in digestion. Soluble fiber, which comes from fruits, oats and other foods, binds with fluid in your gut, forming a gel substance and slowing digestion so that nutrients can absorb through the intestinal walls. Insoluble fiber, found in many vegetables, whole grains and several other sources, speeds digestion and pushes out waste. Both types of fiber are equally important and although fiber-rich foods may have more of one type of fiber, these foods usually have some of both fibers.
Carbohydrates, with the exception of fiber, offer 4 calories per gram. Since carbs are vital for energy and brain function, the largest amount of your caloric intake needs to come from this macronutrient. Between 45 and 65 percent of your total calories should come from carbohydrates, reports the Dietary Guidelines for Americans 2010. For example, if you usually follow an 1,800-calorie diet, you need 810 to 1,170 calories from carbohydrates, which amounts to 202 to 292 grams of carbs. Because fiber does not add calories to your diet, the recommendations are separate. You need 14 grams of fiber for every 1,000 calories you consume. For an 1,800-calorie diet, you'll require 26 grams of fiber each day.
Select whole foods as much as possible to help you meet your carbohydrate and fiber recommendation. Processed baked goods and treats are full of carbohydrates, usually in the form of added sugar, but these foods tend to offer minimal amounts of vitamins, minerals and fiber. Instead, opt for fresh fruits, steamed vegetables and whole-grain foods to add a healthy amount of carbs to your diet while boosting your fiber intake. Skim milk and low-fat dairy foods, as well as shrimp and certain types of seafood, are other lean sources of carbohydrates. Meat, poultry, several seafood varieties and eggs do not contribute carbohydrates to your diet.
Melodie Anne Coffman specializes in overall wellness, with particular interests in women's health and personal defense. She holds a master's degree in food science and human nutrition and is a certified instructor through the NRA. Coffman is pursuing her personal trainer certification in 2015.