Clams Serving: 3 ounce Protein: 21.6 grams Carbohydrates: 4.4 grams Calories: 126 Fat: 1.7 grams Benefits: Clams are excellent low fat protein sources, each 3 ounce serving of clams contains a whopping 24 milligram of iron, enough to last you for two days. It also supply a healthy amount of zinc, an immunity boosting mineral that is notoriously in many diets.