At least the breakfast war among fast-food restaurants is getting a little healthier.

McDonald's is trying out oatmeal at about 600 restaurants in the Northeastern U.S. If the test goes well, McDonald's may add oatmeal to the menu at more than 13,000 of its restaurants nationwide, according to a CNBC report.

The additional fiber and other benefits of oatmeal will be a welcome addition to the waist-expanding breakfast items that have recently been added to the menus at several fast-food restaurants. Hardee's recently added what it calls the Loaded Biscuit 'N' Gravy, a dish with a buttermilk biscuit split with a folded egg and a sausage patty topping on each half, covered with a sausage gravy.

Burger King recently introduced the BK Breakfast Muffin -- sausage, melted cheese and egg on an English muffin. As if that wasn't enough, the chain also added the $2.79 BK Breakfast Bowl, featuring roasted southwestern potatoes, grilled onions and peppers, scrambled eggs and sausage topped with a three-cheese blend and a smoky cheese sauce. At least Subway is selling some healthier breakfast fare: a sandwich made with egg whites.

Breakfast is McDonald's most profitable meal, according to Chicago Business. However, high unemployment has taken a toll on those sales. There are just fewer commuters looking for a quick breakfast, causing McDonald's and other chains to chase after customers by expanding their menus.

While oatmeal is cheap and easy to make at home, it's proven to be a strong seller at other chains like Starbucks, Jamba Juice and Au Bon Pain.

"The battle for breakfast is intensifying," says R. J. Hottovy, a Morningstar analyst interviewed by Chicago Business. "Oatmeal really helped Starbucks, and McDonald's is looking to reinvigorate its breakfast sales."