The recommended daily carbohydrate intake refers to the percentage of a person’s daily calories that should be supplied by carbohydrates. Carbohydrates are the body’s most immediate energy source and include simple sugars like those found in fruits and sweets, and complex carbohydrates, chains of sugars found in starches like potatoes, pasta, and rice. The current recommended dietary allowance (RDA) in the United States, which is a standardized minimum requirement to meet a healthy person’s needs of a particular nutrient, is 130 grams of carbohydrate for adult men and women. Most nutrition experts, however, list a recommended daily carbohydrate intake of up to 60 percent of total calories, or 1,200 calories of carbohydrates in a 2,000-calorie diet. This number may vary, however, depending on whether the individual is an adult or child, is pregnant or breastfeeding, is an athlete, or is trying to lose weight.
As the most available source of fuel, carbohydrates are abundant throughout the body. Carbohydrates are crucial to muscle tissue, the brain, the nervous system, and liver. In the bloodstream it is glucose, or blood sugar.
To maintain this supply, which fuels everything from the muscles during exercise to brain function when taking a test, the recommended daily carbohydrate intake is greater than that of the other two calorie-supplying nutrients, fat and protein. At four calories per gram, carbohydrates should account for anywhere from 45-65 percent of total calories, with recommendations for dietary fat ranging from 20-35 percent and protein ranging from 10-20 percent. For example, a person who is advised to consume a 2,000-calorie-a-day diet may get 1,200 of his calories or 300 grams from carbs, 560 calories from fat, and 240 calories from protein.
Not to be confused with recommended daily carbohydrate intake, RDA is determined by the National Academy of Sciences in the United States, specifically by their Institute of Medicine (IOM). According to a 2003 definition from the IOM, RDA is defined as “the dietary intake level that is sufficient to meet the nutrient requirement of nearly all (97 to 98 percent) healthy individuals in a particularly life stage and gender group.”
In other words, the RDA is a number that in the absence of specific health concerns should apply to most people in a given population as the amount needed to meet minimum nutrient needs. As a minimum, therefore, it is not necessarily reflective of how many total calories from carbs, fat, and protein an individual actually requires — simply the number of grams a person needs to meet those minimum requirements. In fact, the RDA for carbohydrates is listed for adult men and women as only 130 grams, or 520 calories, which is the minimum amount required for the body, specifically the brain, to function properly.
As for total energy needs, with caloric requirements ranging from 1,200 in some smaller adult women to upwards of 5,000 in many athletes, the recommended daily carbohydrate intake for an individual varies so widely that it is taken as a percentage of one’s total calories rather than as a set number of grams per day. Factors influencing one’s recommended daily carbohydrate intake are wide-ranging and include age, weight, athletic demands, and whether the person is pregnant or breastfeeding. Individuals with higher energy needs, such as children and athletes, may do well on a diet with a relatively high percentage of calories coming from carbohydrates — as much as 60-65 percent. Women who are pregnant or breastfeeding require more grams of carbohydrates than they otherwise would, but this is only because their total calorie needs have increased. For those looking to lose weight, some nutrition experts recommend reducing carbohydrate intake to 45-50 percent of total calories as well as reducing overall calorie intake.