Using an item with a timed action while holding down the 'G'(throw) button skips the 'Use' animation, causing the action to happen instantly.
For example, eating food or applying bandages requires a few seconds to accomplish. If you do either while holding down 'G', such actions would take no time to fulfill, prompting no animation, and skipping directly to the desired result.
UPDATE: Holding down 'G' with an item in your hands causes other actions, such as searching for apples or berries, to occur instantaneously. See images below.