What Is A Fast And Slow Carb Diet?

The popularity and effectiveness of low-carb diets lead many to believe that carbs are unhealthy and should be avoided. However, both South Beach and Atkins diet plans add complex carbohydrates to their menus after the initial phase because they provide needed nutrients and fiber important to health. Nevertheless, not all carbs are alike. Some are healthy while others offer no nutritional value at all.

Carbs

Despite the bad reputation carbs have received, they are important to good health. Carbs come in three forms: sugar, starch and fiber. The body converts sugar and starch into glycogen, which is used for energy. Fiber assists with digestion and lowers low-density lipoprotein, LDL, or "bad" cholesterol, reducing your risk of heart disease. The U.S. Department of Agriculture recommends that carbs make up 45 to 65 percent of your daily diet.

Glycemic Index and Glycemic Load

The glycemic index rates carbohydrates on a scale from 0 to 100, according to their impact on blood sugar levels. Foods with a high glycemic index increase blood glucose more than foods with a lower glycemic index. This measure doesn't take into account a carb's digestible content. A newer measure called glycemic load is determined by multiplying a food's glycemic index by the amount of carbs it contains. This provides a more accurate measure of a carb's impact on blood glucose. For example, watermelon has a high glycemic index, but it's mostly water and fiber, which reduces its impact on blood glucose levels.

Fast Carbs

The speed at which a carb is broken down into glucose determines whether it's "fast" or "slow." Fast carbs break down quickly and have a glycemic index above 70 and a glycemic load above 20. They are found in sugar and refined foods such as white bread and rice. Most diets recommend avoiding fast carbs, as they offer little to no nutritional value and can increase your risk of diabetes, heart disease, age-related macular degeneration, ovulatory infertility, colorectal cancer and fatty liver disease.

Slow Carbs

When diet and nutrition experts recommend "good carbs," they are referring to slow carbs. The body requires more time and energy to break down slow carbs. Slow carbs have a glycemic index of 55 or lower and a glycemic load of 10 or lower. Along with energy and fiber, slow carbs provide other nutrients important to good health. They help control weight and reduce your risk of many chronic diseases. Slow carbs are found in vegetables, fruit, beans and whole grains.