I discovered this by accident, tested multiple times and is working.
Well what you do is get 2 of a certain type of food drink or both, and then as you are walking hit one of the 2, or if in a stack just use it, then stop moving immediately after, and spam the button and you will sit down and have double regen.
Works well if in a heroic or raid and want to get things moving faster.
Also works great in arena!