Oat bran refers to the outer layer of a grain of oat. This is the part that is highest in fiber. The fiber provided by oat bran is mainly soluble, which is thought to help reduce blood cholesterol levels and decrease the risk of heart problems, according to the American Heart Association.

Raw Oat Bran

A cup of oat bran provides 231 calories, 6.6 g fat, 16.3 g protein, 62.3 g carbohydrate and 14.5 g fiber. If you use a tablespoon at a time, a likely serving size, it will provide 14 calories, 0.4 g fat, 1.0 g protein, 3.7 g carbohydrate and 0.9 g fiber.

Cooked Oat Bran

If you cook oat bran to serve as hot cereal for breakfast, each cup will give you 88 calories, 1.9 g fat, 7.0 g protein, 25.1 g carbohydrate and 5.7 g fiber. Adding brown sugar, honey or maple syrup will add about 12 to 21 calories and 3.1 to 5.7 g carbohydrate for each teaspoon you add. You can also add 1/4 cup plain yogurt to add some creaminess to your cooked oat bran and add an additional 69 calories, 3.7 g fat, 3.9 g protein and 5.3 g carbohydrate to your meal.

Oat Flakes

Oat flakes are a whole-grain food and include all three part of a grain: the endosperm, the germ and the bran. A serving of 1/3 cup dry oat flakes provides 101 calories, 1.7 g fat, 3.5 g protein, 18.1 g carbohydrate and 2.7 g fiber. Any added sweeteners, fruits, nuts, milk or yogurt will raise the calorie count.

Using Oat Bran

If you wish to add more oat bran to your diet to obtain the health benefits offered by its fiber, sprinkle a tablespoon or two on your morning bowl of breakfast cereal or add it to your yogurt or smoothie. You can also add oat bran to many of your favorite recipes for muffins, bread, cookies, pancakes or cakes and you can even sneak it in meatballs or meatloaf.