Lentil soup is a healthy when prepared using whole food ingredients, and limiting added salt. Lentils are an excellent source of plant protein, and fiber. One bowl of this soup has 12 grams of protein, and 15 grams of fiber. Protein is needed to build muscle and strength, as well as help with multiple functions of the body, while fiber helps with a healthy digestive track. This soup is low in calories, coming in at under 200 calories per serving, and only 1 gram of fat. With the added onions, carrots, and celery, you're also getting a healthy dose of vitamins and minerals such as vitamin A, vitamin C, vitamin B6, potassium, and folate.