Lentils are Pulses and are noted for being lens shaped. Lentils have plenty of protein without saturated fat.  It's best if other proteins are eaten on the same day as lentils to complement the lentils and help the body build complete protein.  The proteins in Wheat, rye and barley also complement the protein in lentils.  There are many different types of lentils.
- Lentils, mature seeds, cooked, boiled, without salt This is a technical website.
- Foods with highest ratio of Methionine+Cystine:Isoleucine This web page which is also technical gives foods that complement the protein in lentils. Not all are vegetarian.
- 12 Complete Proteins Vegetarians Need to Know About This web page is less technical, gives foods that complement each other including lentils. All are vegetarian.