What Are Carbohydrates Composed Of?

As a group, carbohydrates are composed of sugars, starches and fiber.
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Carbohydrates, or carbs as they are often called, get a bad rap by calorie counters and dieters alike because of the belief that they are fattening and unhealthy. As a general group, carbs consist of sugars, starches and fiber. Within that group, the refined carbs are the unhealthy ones; others such as whole grains, fruits and vegetables provide a bevy of vitamins, minerals and antioxidants.


The word "sugar" encompasses more than just common white, granulated sugar. Different types of sugar exist, which come from various food sources; some are healthier than others. For example, milk contains the sugar lactose. The sugar in soft drinks comes from high fructose corn syrup, which according to a January 2012 article in "Current Diabetes Reports," is associated with weight gain and Type 2 diabetes. Through the digestion and absorption of carb-containing foods, your body produces a simple sugar called glucose, which is your main energy source. Sugar is listed on food ingredient labels under many different names, including dextrose, honey, molasses, invert sugar, corn syrup, corn sweeteners, maple sugar, turbinado sugar and high fructose corn syrup.


Starch is a complex carb which consists of many sugar molecules bonded together. During digestion these bonds are broken, releasing sugars which are then converted to glucose. Excesses are stored as fat. Breads, cereals and grains, legumes and potatoes are all excellent food sources of starch. Make most of your choices whole grains, as opposed to refined ones, and you'll reap the nutritional benefits they offer -- vitamins, minerals and antioxidants.


Fiber is found solely in plants, so don’t look to a diet laden with meats, milk and cheese to provide any. You can’t digest fiber; it moves wastes through your digestive system quickly, keeping you regular. A December 2012 article in "Current Atherosclerosis Reports" reviews the heart-healthy benefits of fiber, which include lowering your cholesterol and blood pressure and assisting with weight control. Fiber also helps prevent unhealthy dips and peaks in your blood sugar. Legumes, oats, barley and apples are especially good at lowering your blood cholesterol. Add nuts, seeds, fruits, veggies and whole grains liberally to your diet to maximize your fiber intake.

How Much is Enough?

No daily recommendation for sugar intake exists, since your body gets what it needs from starchy foods. The Institute of Medicine recommends limiting added sugars in your diet to 25 percent of total calories, as most comes from non-nutritious junk foods such as soft drinks, desserts and candy. Carbs should comprise 45 to 65 percent of your total calorie intake. Aim for 25 grams of fiber daily, recommends the IOM.

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