Sounds like a new detective show: Jeff Sleepier and his beautiful, raven-haired partner, Susie Fuller. But that is not what I am writing about. I am referring to aspects of getting older. Those of us who are older have a moral responsibility to alert those entering that state as to its features. Two of those features that you might not have expected are being sleepier and being fuller, less hungry faster.
You might not sleep as long or as soundly as you did in your teens and twenties. Sleep science is emerging as a real effort to understand sleep, protect our sleep and enhance it where possible. We listened to a Great Course on sleep but a good deal of it was over my head, with lots of technical names of chemicals and neurotransmitters. When my father was in his 90's, he fell asleep at the wheel of his car and crashed into a tree. He was going slowly at the time but it all came as a surprise. He hadn't been feeling sleepy and he wasn't sleep deprived. I know some people suffer from narcolepsy, experiencing unexpected and unwanted periods of sleep at random times during the day. I used to work with a high level executive who had narcolepsy and would grab a piece of scrap paper or a bit of napkin and chew it in a meeting to keep awake.
As an older person, you may need a nap in the afternoon. You may find that you are quite refreshed after 15 or 20 minutes of napping.
Another feature of getting older was well-described by a friend who said that these days, she takes one bite and she is ready for a doggy-bag. For readers from elsewhere, it is the custom in American restaurants to request a "doggy bag", supposedly a package of meal leftovers for one's pet but actually the makings of tomorrow's breakfast or lunch. As noted in some of these search results, the reasons older people eat less can be surprisingly varied.
Sweets may still be attractive but of course, should not be overdone. Vegetables matter very much and being lighter may be more attractive than a big steak. We had a relative who became fixated on the idea of constipation and kept overdosing on laxatives that he didn't need. Several times, he dehydrated himself to the point of needing hospitalization. Vegetables can help with that, too, but they need to be attractively cooked. As a youngster, I always like lettuce but dismissed it as unimportant. However, the physician Joel Fuhrman states that lettuce is an valuable food.