Dietary Reference Intakes (DRI), Report 6, Part 1: Energy, carbohydrates, and fiber

Estimated Energy Requirement (EER) has been defined as the average dietary energy intake which is expected to maintain energy balance in a healthy adult of defined age, gender, weight, height and level of physical activity. In children and pregnant and lactating women, EER also includes the needs resulting from the deposition of tissues or the secretion of milk. While EERs can be estimated for four levels of activity from the equations provided, the active Physical Activity Level (PAL) is recommended to maintain health and decrease risk of chronic disease and disability. Carbohydrates (sugars and starches) provide energy to the body cells. Based on the average amount of glucose utilized by the brain, the RDA for carbohydrate has been estimated to be 130 g/day for adults and children. Because of the risk for coronary heart disease (CHD) which is involved in both low- and high-fat diets, and because of the increased risk for CHO at higher carbohydrate intake, an Acceptable Macronutrient Distribution Range (AMDR) for carbohydrates of 45 to 65% of total dietary energy has been fixed for adults, corresponding to an AMDR for fat of 20 to 35% of dietary energy. Intake of added sugars should not exceed 25 percent of the total dietary energy supply. Dietary fiber comprises non-digestive carbohydrates and lignin present in plants, while functional fiber is defined as isolated and/or chemically modified or synthesized non-digestible carbohydrates which have been shown to have beneficial physiological effects in humans. Total fiber is the sum of dietary fiber and functional fiber Viscous fiber delay the gastric emptying of ingested food into the small intestine; this may result in a sensation of fullness and reduced postprandial blood glucose concentrations. They may also influence the absorption of dietary fat and cholesterol as well as the enterohepatic recirculation of cholesterol and bile acids; this may result in reduced blood cholesterol concentrations. Recent studies on dietary fiber and CHD suggest an Adequate Intake of total fiber of 38 and 25 g/day, resp., for men and women aged 19 to 50 years. With regard to energy, carbohydrate and fiber considerable differences between the D-A-CH reference intakes and DRI do not exist. Those who have fixed the D-A-CH reference values for nutrient intake may have used some different conceptions, databases, definitions and procedures which are discussed in detail.