Carbohydrates are macronutrients that play a vital role in supplying your body with the energy it needs to support its daily functions. Your body needs about twice the amount of carbohydrates as it does fat, and about three times that of protein. The Food and Nutrition Board sets acceptable macronutrient distribution ranges for all macronutrients, which are presented as a percentage of total calories. The Institute of Medicine, or IOM, has not identified a maximum upper limit for maximum carbohydrate intake at which adverse health effects occur, though the Acceptable Macronutrient Distribution Range, or AMDR, value provides a percentage that allows sufficient intake of other nutrients.
While other nutrients tend to vary with age and sex, the AMDR for carbohydrates remains constant for all populations. According to the IOM, carbohydrates should account for 45 to 65 percent of your total calories. If you wish to lose weight or have a sedentary lifestyle, you will want to eat your carbs at the lower end of the scale, near 45 percent. Athletes and active individuals do fine near 65 percent. The USDA's Dietary Guidelines for Americans 2010 states that you just need to make sure you stay within the 45 to 65 percent range, and that you make healthy food choices. If you consume a 2,000-calorie diet, you would need between 900 and 1,300 calories from carbohydrates, or about 225 to 325 grams, each day. The IOM does not provide an AMDR for infants in their first year of life due to a lack of clinical data for this age group.
Added sugars are specific types of carbohydrates that enter the bloodstream quickly, spike your blood glucose levels and often produce a "crash" several minutes after eating them. According to the American Heart Association, added sugars may induce weight gain, diabetes and cardiovascular problems. The IOM does not provide a specific AMDR for added sugars, but it advises consuming fewer than 25 percent of your total calories from these carbohydrates to reduce your risk of these health concerns.
Fiber is another form of carbohydrate that serves a number of positive health functions. Dietary fiber can reduce blood cholesterol, maintain normal blood glucose levels, prevent intestinal blockage and promote digestive regularity and may protect against colon cancer. As with added sugars, the IOM does not provide a specific AMDR range for fiber but includes adequate intake values in grams. Adult men should consume about 38 grams of fiber each day, while adult women should consume 25 to 26 grams.
The best sources of carbohydrates are complex sources, or those that contain multiple chains of sugar molecules linked together. These carbohydrates have a more gradual effect on blood glucose levels and can help you feel full longer. Examples of complex carbohydrates include whole grains, fruits, vegetables and legumes. Complex carbohydrates also tend to be higher in vitamins, minerals and fiber than simple carbohydrates. Try to avoid processed and packaged foods, candies and soda as your main sources of carbohydrates as these can be high in added sugars.
- Institute of Medicine: Dietary Reference Intakes: Macronutrients
- MedlinePlus: Carbohydrates
- American Heart Association: Sugars and Carbohydrates
- Harvard School of Public Health: Fiber
- USDA Dietary Guidelines for Americans 2010
- KidsHealth.org: Learning About Carbohydrates
- Familydoctor.org: Added Sugar -- What You Need to Know