When I was growing up my Mom would often shop at outlets and factory seconds stores. She was thrifty. Most of our clothes had 'Irregular' stamped somewhere on them. I try not to read too much into it...
If we were living in ancient India we would have been stamped 'Vishama'.
Vishama is anything that does not happen in a regular way. Anything 'off schedule' or atypical.
This can be in relationship to schedules: eating lunch at 11am some days and 4pm others. It can be related to what you eat: sushi one day and a bowl of Cheerios the next. It can be related to your energy levels: productive and thrilled to be alive before lunch and lethargic and snarky after.
Of course regularity begets regularity. My great grandma Emma ate a Velveeta (TM) sandwich on white bread and 1/2 of a Red Delicious apple everyday (except Sunday) at 12 noon. She was quick witted, even keeled, spry and rarely sick until her death at 86.
Regular eating, sleeping, even thinking habits are good for our body. When we sleep at the same time daily our body is prepared for sleep when we lie down and easily lets loose of the tethers of the senses. When we eat at the same time every day our body is prepared to digest, assimilate and nourish itself.
And when we do both of these things our energy levels will be even and dependable day to day and year to year. When our energy levels are even our tissues can be strong, resilient, and resistant to disease of all sorts.