An entire oatmeal bread loaf contains 1800 cal. It should last you a week or so if you include it in your breakfast on a regular basis.
But there is more to that oatmeal bread
The loaf includes 75g protein, only 300g carb and 12 g fiber.
Needless to say, the majority of that carb is coming from oats, hence, good carb.
You can always pump this up easily by including nutritious chia seeds or nuts of your choice.