Your biology, all the way down to the DNA level works on a circadian rhythm. A near 24hr cycle. Disturbing that with poor routine leads to increased stress on the body and mind. If continued long term, chronic illness is most often the result.
Creating routines durning in your day and week, especially while in lockdown, around meal times, sleep, activity/exercise and mindfulness is a strong way to support and even promote good health, both of body and mind.
Two of the strongest influences on circadian rhythm are light and meal times.
For a healthy rhythm it is recommended that we all rise and sleep with the sun. The more regularly a person is able to watch the sun rise and then avoid artificial light after it has set, will continue to strengthen the circadian rhythm.
The second is when a person eats. It is recommended to eat within a 9-10hr window during the day and then allowing 2-4hrs after dinner for proper digestion before retiring for a good nights sleep.
This may initially be a challenge too many peoples current lifestyles but if you are prepared to change your schedule you can change your life and improve or maintain good health using routine that promotes a strong circadian rhythm.