The major difference in substituting zucchini for pasta noodles is the calorie count. You would have to eat 11 cups of zoodles to equal 1 cup of noodles in calories. Zoodles also have a significantly higher amount of potassium than plain noodles. Noodles have 10 times the amount of carbohydrates than zoodles. Zucchini are also high in Vitamin A and C, which makes it a nutrient-rich food versus noodles that offer almost no nutrients. If you are looking for a substitution that offers nutrients, zoodles are the way to go.