good lord this is over-intellectualised nonsense. it's not complex or ancient, it's actually part of the meiji era aping of western cultural semiotics, and the

good lord this is over-intellectualised nonsense. it's not complex or ancient, it's actually part of the meiji era aping of western cultural semiotics, and the OP seems to misunderstand the etymology. just say itadakimasu before a meal and gochisosama after. maybe a few days later, if someone else bought you the meal: 先日（昨日）はごちそうさまでした