Werepyres seem to require both food and blood at the same time, while not being able to digest food. This causes the following problems:

• your hunger bar is completely obscured by the blood bar. I'm assuming this is because it's supposed to replace your hunger, but doesn't do so correctly.
• hunger still invisibly depletes, meaning you will eventually (and quite quickly) begin to starve, lacking stamina to sprint.
• food applies a variety of status effects when you eat it, preventing hunger gain in any remotely efficient manner.

experiencing this problem on 1.19.2 with besmirchment-1.19.2-11.jar.