The recommended daily allowance is a term used to specify the amount of a nutrient that meets the needs of almost all individuals in a specific age and gender group, according to “Nutrition and You” by Joan Salge Blake. Recommended daily allowances for protein and fiber differ based on characteristics such as age, sex and weight.
Functions of Protein
Protein provides the structural and functional materials in every cell in your body, according to Blake. Protein is a major component of skin, muscles and organs and is part of most of the fluids in your body. Protein also contributes to immune system health, proper growth and cell repair. To keep your body functioning properly, it is important you consume enough protein every day.
Protein recommendations are specific to each individual. You can determine your protein needs by calculating it as a percentage of your daily calories. Protein, which contains 4 calories per gram, should contribute 10 to 35 percent of your daily calories. For someone on a 2,000-calorie diet, this would equal 50 grams to 175 grams of protein per day. You can also follow the recommendation of the Institute of Medicine, as reported by the Centers For Disease Control and Prevention. For an adult woman over the age of 19, the daily protein recommendation is 46 grams, and for men it is 56 grams.
Functions of Fiber
Although best known for its role in digestive health, fiber has many other health benefits as well. Adding fiber to your diet can help reduce blood pressure, cholesterol levels and chronic inflammation. Fiber also helps slow down the digestion of sugar, which can help keep your blood sugar within normal range, according to the BD Diabetes Learning Center. Steady blood sugar levels are associated with a decreased risk of type 2 diabetes. Foods high in fiber also help you feel full longer. This can help prevent overeating, which may aid in controlling weight and lead to weight loss.
Types of Fiber
Fiber is divided into two categories, soluble and insoluble. Insoluble fiber does not dissolve in water. When you eat insoluble fiber, it absorbs water, increasing stool bulk and helping move fecal matter through the digestive system. The best sources of insoluble fiber include whole-wheat flour, vegetables and nuts. Soluble fiber dissolves in water and turns into a gel. Soluble fiber moves through the digestive system slowly and can help lower glucose and cholesterol levels, according to Harvard School of Public Health. Beans, oats, apples, carrots and citrus fruits contain soluble fiber.
Although there is no RDA or recommended daily allowance for fiber, there is a recommended adequate intake from the Institute of Medicine. Fiber recommendations vary based on age and sex. Men aged 50 and younger should aim to consume at least 38 grams of fiber per day. Men over the age of 50 should consume at least 30 grams of fiber daily. Women aged 50 and younger should aim to consume 25 grams of fiber per day, and those over 50 should consume 21 grams. It is best to get your fiber from whole foods rather than from fiber supplements, because while fiber supplements do provide fiber, they lack the other nutrients whole foods provide.
- MedlinePlus: Protein in diet
- BD Diabetes Learning Center: Soluble Fiber: Another Way to Fight High Cholesterol
- Nutrition and You: Joan Salge Blake
- Centers For Disease Control And Prevention: Nutrition For Everyone: Protein
- Harvard School of Public Health: Fiber
- Institute of Medicine: Dietary Reference Intakes: Macronutrients