I think there are some people who eat once every 24 hours and still is healthy as a horse.

Hmmmm, those people are pretty few and weird, can you eat once a day, for me I know I just can't, I won't be able to function properly, and I think majority of the world population is also this way.

the elderly population were supposed to sleep for 7 to 8 hours a day, in reality, they probably slept like 5-6 hours or lesser

Yea, it is what is recommended for their well-being. They might not be able to sleep that much, but that doesn't change the fact of what is actually proper for their well-being.

Do you think it is a good idea to distribute your hours of sleep in a day into a few naps which will total up to the same number of hours or less?

For me, that's hardly possible, for students and workers, because they won't be able to meet up that every 4 hours nap, and missing one would be very very bad. What I would advise is the Biphasic Sleep Pattern, which I consider is the best sleep pattern. You have about 5-6 hours night sleep and siesta lasting up to 90 minutes within the day.

Thanks for coming around @conficker