Peanuts are part of the legume family. Legumes, which also include beans and peas such as lentils and black beans, can be classified as a vegetable. Peanuts can also be part of the protein food group.
Legumes are seeds that are edible and encased in pods. Even though peanuts are usually consumed as nuts, they differ from walnuts, almonds and pecans. Peanuts grow underground, and foods that are classified as true nuts grow on trees.
An ounce of raw peanuts contains 7.3 grams of protein and 2.4 grams of dietary fiber. There are four types of peanuts. The Virginia peanuts are commonly referred to as cocktail nuts, while the Spanish peanuts are often used in candies. Runner peanuts are best for roasting, while Valencia peanuts are suitable for boiling.