In Rustboro City, an Ace Trainer gives you a Float Stone (halves weight). If you leave and return, he is replaced by a Hiker who mentions gaining weight, implying he was the trainer and the stone was the only thing keeping him slim.
08C6F5E0 03840032 (Replaces first medicine slot). Pokemon Alpha Sapphire Cheats And Secrets
These are legitimate in-game rewards that act like "cheats" for progression: In Rustboro City, an Ace Trainer gives you
Game Freak buried several references and hidden mechanics within the Hoenn remakes: In Rustboro City