Carbohydrates

Carbohydrates are organic compounds, found in plant-based and processed foods, that are responsible for providing your body with energy. There are two categories of carbs: simple and complex. Simple carbohydrates have one or two sugars and are absorbed and digested more quickly. Simple carbs are found in fruits, vegetables, and dairy, as well as processed candy, desserts, and colas. Complex carbs, which have starches and fiber, must be digested before it's converted into energy. Examples of these types of carbs include potatoes, white bread, white rice, and beans.^{[1, 3]}

The 2010 Dietary Guidelines for Americans suggests that between 45% and 65% of total daily calories -- or 225g to 325g -- come from carbohydrates, especially complex carbs and natural sugars. Eat more fruits, vegetables, whole-grain foods, and legumes (beans, lentils, and dried peas) to boost your carb intake.

Uses

Carbohydrates provide the body -- especially the brain and nervous system -- with energy. The body gets this energy from glucose, a product of carbohydrate breakdown.^[1]

Other uses include:

• Protection against disease, cardiovascular disease in particular. Fiber may curb obesity and type 2 diabetes, and promote digestive health.

• Weight control: Vegetables, fruits and whole grains promote a feeling of fullness, which can reduce overeating. Glucose that is broken down from sugars, refined grains, and starches provides the body with bursts energy, which is great for athletes. Pick complex carbohydrates that burn more slowly and sustain energy longer.

Fiber is the part of a plant that humans can't digest, but it still plays an important role in your health:^{[2, 4]}

• Slows nutrient absorption, which may help prevent erratic blood sugar levels

• Lowers cholesterol

• Makes you feel fuller longer, which can reduce binge snacking or overeating

• Prevents constipation

The amount of fiber we need decreases with age:

• Men require 38g at age 50 and younger, but 30g after age 50.

• Women require 25g at age 50 and younger, but 21g after age 50.

Glycemic index

The glycemic index classifies carbohydrates based on their potential to raise blood sugar levels. A score of 70 and above means the food has a high glycemic index, while a score of 55 and below means the food has a low glycemic index. Whole grains, fruits, vegetables, low-fat dairy products and legumes rank low on the glycemic index since they are slower to digest and don't spike blood sugar. Potatoes, white bread, and corn, though, rank high since they cause blood sugar levels to rise quickly. You don't have to stop eating high glycemic foods, just go easy on them.^{[3, 4]}

Many factors can affect a food's glycemic index, including:

• Form

• Type of starch

• Amount of fiber

• The degree of ripeness

• Extent of processing

Concerns / Potential Side Effects

• Eating too many carbohydrates can spike total caloric intake and lead to weight gain and obesity.

• Eating too few carbohydrates can cause malnutrition.

• If you don't get enough carbohydrates, you might find yourself making up for it by eating too much fat.

• Foods that are sugar free tend to have added sugar alcohols and other sweeteners. These can cause intestinal problems, such as gas and diarrhea. Look for lactitol, mannitol, and sorbitol on the list of ingredients.

• Low- and no-fat foods often contain higher amounts of sugar to make up for reduced fat.

• Some carbohydrates are beneficial while others can increase your risk for diabetes and coronary heart disease.

Considerations

• Americans tend to eat white -- or refined -- grains, and generally don't get enough fiber.^[2]

• Added sugars provide plenty of calories and aren't very nutritious. Look for high fructose corn syrup or brown/white sugar on the ingredients list.^[2]