What kind of Campbell's soup?
Some soups would provide at least some nutrition, since they contain vegetables and meat. However, if you are just talking about tomato soup, while it is good for you, isn't going to give you a lot of protein or energy.
Regardless of what kind it is, canned soups contain A LOT of sodium. Excess sodium intake is linked to: hypertension/high blood pressure and heart disease, fluid retention, and kidney stones. A high-sodium diet increases the need for potassium.