Lentils have been a staple in the human diet since ancient times. A member of the same legume family that includes peas and dried beans, lentils cook quickly -- they don't require any presoaking -- and are an inexpensive, low-fat source of protein, vitamins, minerals and fiber. The dozens of types of lentils vary in color, size and texture, but are similar nutritionally, says Columbia Health. Red lentils, which are hulled, halved yellow lentils, become extremely soft when cooked and are commonly used in curry, soups or the traditional Indian dish dal.
The U.S. Department of Agriculture reports that a 1-cup serving of cooked lentils, including red lentils, contains 230 calories. Only about seven of these calories are contributed by the 0.75 grams of total fat in each cup. Of this amount, 0.1 grams are supplied by saturated fat, less than 1 percent of the 15-gram saturated fat limit advised for healthy adults following a 2,000 calorie diet. Lentils do not contain cholesterol.
Excellent Source of Fiber
Nearly 70 percent of the total caloric content of red lentils is supplied by carbohydrates. Each 1-cup serving of cooked red lentils contains approximately 40 grams of carbohydrates, with 15 grams of dietary fiber, or 44 percent of the recommended daily fiber intake for a man and 53 percent of the requirement per day for a woman. A diet rich in fiber from foods like lentils may lower your risk of stroke, hypertension, heart disease, diabetes and digestive disorders. Red lentils also contain a small amount of sugar: 3.6 grams per cooked cup.
High in Protein
Lentils contain more protein than most other types of beans and legumes, including black, white and pinto beans. A 1-cup serving has 17.8 grams of protein, an amount that fulfills almost 32 percent of a man's daily protein needs and 38 percent of a woman's. Red lentils do not contain all of the amino acids your body requires. By eating whole grains within 24 hours of consuming lentils, however, you can obtain the amino acids the legumes lack.
Dense With B Vitamins
Red lentils are an outstanding source of B vitamins, including vitamin B-6, thiamin and pantothenic acid. They are especially high in folate -- also known as vitamin B-9 -- with 358 micrograms in every cooked cup. Adults should have 400 micrograms of folate each day, and eating 1 cup of red lentils would fulfill almost 90 percent of this requirement. Your body needs adequate folate to synthesize red blood cells and DNA and to aid in energy metabolism.
Source of Iron
A 1-cup serving of cooked red lentils contains 6.6 milligrams of iron. (See Reference 5) A man should have 8 milligrams of iron daily, and a cup of red lentils would supply 82 percent of his requirement. (See Resource 1) A woman, who needs about 18 milligrams of the mineral each day, would obtain 37 percent of her recommendation of iron from a cup of red lentils. (See Resource 1) You can increase the amount of iron you absorb from lentils by eating the legumes with an animal protein or a food rich in vitamin C. (See Resource 1) Try stirring red lentils into a fish or poultry stew containing a source of vitamin C like tomatoes.