Red lentils come from India and Turkey. They are sold in dried form and as they are already hulled they cook quickly. Red lentils are a common ingredient in curries, soups, and stews.
From Wikipedia: “The lentil (Lens culinaris) is an edible pulse. It is a bushy annual plant of the legume family, known for its lens-shaped seeds. It is about 40 cm (16 in) tall, and the seeds grow in pods, usually with two seeds in each.
In South Asian cuisine, split lentils (often with their hulls removed) are known as lentils. Usually eaten with rice or rotis, the lentil is a dietary staple throughout regions of India, Pakistan, Bangladesh and Nepal. As a food crop, the majority of world production comes from Canada, India and Australia.”
Red lentils have already been hulled and as a result can be prepared more quickly than other legumes. This is also the reason why they don’t have to be soaked before cooking. During the cooking process, red lentils take on a yellowish color. Since they soften and split easily, they work well for curries, soups, and stews.
“According to the USDA National Nutrient Database, 100 g of raw lentils (variety unspecified) provide 353 calories; the same weight of cooked lentils provides 116 calories. Raw lentils are 8% water, 63% carbohydrates including 11% dietary fiber, 25% protein and 1% fat. Lentils are a rich source of numerous essential nutrients, including folate, thiamin, pantothenic acid, vitamin B6, phosphorus, iron and zinc, among others. When lentils are cooked by boiling, protein content declines to 9% of total composition, and B vitamins and minerals decrease due to the overall water content increasing (protein itself isn't lost).
Lentils have the second-highest ratio of protein per calorie of any legume, after soybeans.
The low levels of readily digestible starch (5%), and high levels of slowly digested starch, make lentils of potential value to people with diabetes. The remaining 65% of the starch is a resistant starch classified as RS1. A minimum of 10% in starch from lentils escapes digestion and absorption in the small intestine (therefore called "resistant starch").
Lentils also have anti-nutrient factors, such as trypsin inhibitors and a relatively high phytate content. Trypsin is an enzyme involved in digestion, and phytates reduce the bioavailability of dietary minerals. The phytates can be reduced by prolonged soaking and fermentation or sprouting.”
“Lentils are relatively tolerant to drought, and are grown throughout the world. FAOSTAT reported that the world production of lentils for calendar year 2013 was 4,975,621 metric tons, primarily coming from Canada, India and Australia.
About a quarter of the worldwide production of lentils is from India, most of which is consumed in the domestic market. Canada is the largest export producer of lentils in the world, and Saskatchewan is the most important producing region in Canada (growing 99% of Canadian lentils). Statistics Canada estimates that Canadian lentil production for the 2009/10 year was a record 1.5 million metric tons. The most commonly grown type is the Laird lentil.
The Palouse region of eastern Washington and the Idaho panhandle, with its commercial center at Pullman, Washington, constitute the most important lentil-producing region in the United States. Montana and North Dakota are also significant lentil growers. The National Agricultural Statistics Service reported United States 2007 production at 154.5 thousand metric tons.”
Under optimal storage conditions, red lentils keep for quite a long time (almost a year). They must be stored in a dry place that if possible is cool and protected from light.
"Lentils were a chief part of the diet of ancient Iranians, who consumed lentils daily in the form of a stew poured over rice."