That's because there are few low tier people in the game Arietna. Food needs to be at your highest *possible* rating, not your current one. So even as a level 1 I still need to eat tier 6 food. The only people who can eat tier 1-4 food are single classed people who are just starting the game.
I've purchased ~500 silver worth of tier 6 food since this change went live. Less than 40 silver of tier 5, and none of anything else.