You're definitely wrong about the 1/3 hadeeth Bro DhulQarnaen!! That's a Saheeh hadeeth Barakallahu Feek and it was not made up by some Awwam people just to include into their method of eating. Look at the hadeeth here

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Rasulullah said:
“The son of Adam does not fill any vessel worse than his stomach. It is sufficient for the son of Adam to eat a few mouthfuls, to keep him going. If he must do that (fill his stomach), then let him fill one third with food, one third with drink and one third with air.” Narrated by al-Tirmidhi , Ibn Maajah ,classed as saheeh by al-Albaani in al-Silsilah al-Saheehah
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