I have never hear of, or seen 음료식 written.
But I can guess that it tries to describe 죽(porrige) in another way.
Because 음료 means 'beverage' which you can drink easily without chewing.
And 식 means 'meal/diet'.
So 음료식 refers to a type of meal you can have without mastication.
But as I said, I've never heard of it. Maybe some doctors or dietitions would use this term.