There's no one-size-fits all approach to the amount of carbs you need daily, and the recommended dietary guidelines allow some leeway so you can find a carb intake that works for you. People need a minimal amount of carbs every day, however, to provide the brain with the glucose it needs to function. Otherwise, you should consider your overall health, body weight and activity level to determine your normal daily intake of carbs.
Carbohydrates Energize the Brain and Body
Carbohydrates are an essential part of your daily diet because they contain the glucose that fuels your body and brain. In fact, providing energy is the only job filled by two types of carbs -- sugar and starch. While the body can convert fat and protein into energy, those nutrients have other roles that are critical for your health. If you don't consume the right amount of carbs, proteins that are needed to build and repair muscles and other tissues are diverted away from their primary job and turned into glucose.
The type of carb you eat is just as important as the amount. High-glycemic carbohydrates contain simple sugars without enough complex starch and fiber to offset the rapid digestion of sugar. These carbs -- think of foods with added sugar and processed flour or rice -- are quickly digested and spike blood sugar. Sure, they give you a short-lived boost of energy, but it's followed by a dip in blood sugar that leaves you fatigued and hungry. Complex carbohydrates such as whole grains, beans, fruits and vegetables contain simple sugar plus starch and fiber. They're slowly digested so you get sustained energy without big swings in blood sugar.
Normal Carbohydrate Intake per Day for Good Health
The smallest amount of carbohydrate you should consume each day -- 130 grams -- is the recommended dietary allowance established by the Institute of Medicine. The institute reports that this amount is based on the fact that carbs are the primary energy source for the brain. In other words, 130 grams keeps you alive but isn't necessarily ideal for peak health or an active lifestyle. In addition to lacking glucose for your daily activity, a limit of 130 grams means you're probably not eating enough food to get all the nutrients you need from healthy complex carbohydrates.
The Acceptable Macronutrient Distribution Range, or AMDR, defines the normal carb intake as determined by the Institute of Medicine. It recommends getting 45 to 65 percent of your total daily calories from energy-providing carbohydrates. The lower amount ensures your diet includes a healthy proportion of carbs, fats and protein. The upper amount prevents overconsumption that could lead to weight gain and chronic diseases such as diabetes. You can use the range to choose the amount of carbohydrate that's appropriate for your activity level.
Increase Carbs for Intense Activity
If you're engaged in sports or any high-energy activity, your definition of "normal" carbohydrate intake may change. During times of intense physical activity, the body needs enough carbohydrate to replenish glycogen stores and maintain body weight. The American College of Sports Medicine advises that athletes consume 2.7 to 4.5 grams of daily carbs for every pound of body weight. But you'll need more than that if you participate in extreme training and races that last longer than four hours. This type of intensive activity requires as much as 5.5 grams of carbs per pound, notes the Academy of Nutrition and Dietetics.
Adults can store about 500 grams of total carbohydrate, which includes 400 grams of glycogen stored in muscles, reports Iowa State University. During low-intensity activities, glycogen stores can energize muscle for about 90 minutes. All glycogen is depleted in about 20 minutes during high-intensity exercise. To achieve optimal performance and avoid fatigue, the body depends on maximum glycogen stores. Lay the groundwork by including complex carbs as a regular part of your daily diet. Optimize glycogen with complex carbs before exercise and simple carbs during exercise. Then replenish stores by eating 0.5 to 0.7 gram of carbs per pound of body weight during the first 30 minutes after your activity.
Getting Enough Fiber
Dietary fiber isn't a key source of energy, but it's an essential carbohydrate. Foods such as fruits, vegetables, beans and whole grains contain two types of fiber: soluble and insoluble. Insoluble fiber absorbs water as it travels through the large intestine, which adds bulk to stool and prevents constipation. Soluble fiber helps lower cholesterol and prevents spikes in blood sugar after you eat. Some types of soluble fiber, such as beta-glucan in oats and pectin in fruits, are fermented by beneficial bacteria that live in the large intestine. During fermentation, soluble fiber produces about 1.5 to 2.5 calories per gram which can be used by the body.
The normal intake of fiber isn't as variable as the amount recommended for sugar and starch. Women should consume 25 grams of total fiber daily, while men need 38 grams, recommends the Institute of Medicine. The thing to remember is this: The only way you'll reach the recommended intake is by including fiber-rich foods at every meal. For example, three foods with the most fiber – 1/4 cup of wheat bran and 1/2 cup of beans and lentils – each contain 6 to 8 grams of total fiber per serving. A 1/4-cup serving of wheat germ, an apple or pear, and a cup of blueberries or strawberries each provides 4 to 5 grams of fiber. It's easy to see that you'll need multiple servings to get your daily fiber.
- Institute of Medicine: Dietary Reference Intakes: Macronutrients
- American College of Sports Medicine: Medicine and Science in Sports and Exercise: Nutrition and Athletic Performance
- Academy of Nutrition and Dietetics: Eat Right for Endurance Sports
- Iowa State University: Carbohydrate
- Institute of Medicine: Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
- Tufts University: Fiber