Also allows him to carry additional people and items, and store the items. However, might be better to have an SUV or similar for greater and more secure storage.
Now I need a comic where a Flash uses the speed force to carry the entire Justice League Watchtower into another dimension and it just follows the characters who now have to live with the fact that they failed in their original universe. Green Lantern retires because the hope is gone, Aquaman works out a schedule with the new universe Aquaman so they can split the responsibilities of head of Atlantis and superhero work, etc.
Most media just has superheroes consume regular calories for their body size it seems. Where does all this extra energy come from? Guess Flash has the speed force, Hulk the gamma radiation, and Superman the star power. Only two I remember someone eating extra calories is Pecorine from Princess Connect and that one girl who can create anything from My Hero Academia.
And I seem to recall a few times where one of the various flash-like characters ate a huge amount of food without thinking about it. Wally ate a 3-5 gallon tub of ice cream that had been meant for someone's birthday, if I recall.