Legumes are a very good source of carbohydrates and proteins. They are the richest source of proteins than any other vegetable. Legumes are known to contain a high amount of complex carbohydrates. They also contain omega 3 fatty acids and various other vitamins and minerals. Legumes being rich in fiber help with digestion and maintaining healthy weight. Legumes like lentils, chick peas, split peas, soybeans, kidney beans and pinto beans contain the highest amount of proteins and complex carbohydrates.