[what I had for breakfast today: a cup of miso soup, then jasmine rice, over-medium egg, a bit of fried chicken skin, and a pile of sauerkraut]
I've always preferred sitting on the floor to sitting in a chair. If it were socially acceptable, I'd probably eat all my meals, do all my consults and take all my meetings cross-legged on the ground. When I was in high school I briefly campaigned to be permitted to sit on the floor during classes, with unbrilliant arguments like, "Who does it hurt?" and "Look, you can't fall off the floor."
All I knew at the time was that I was more comfortable on the floor than in a chair. Nowadays, if you Google "healthy sitting" or "chairs and health" you'll find a multitude of reasons to park your booty on the baseboards every chance you get. (I wish I'd had them when I was making my case to my Modern European History teacher.) Here are just a few: it's better for your hips, your back, your neck, and your internal organs. Eating while sitting on the floor benefits your digestion. Working on the floor enhances your productivity.
And it's a good practice if your goal is to maintain mobility over the long term: consider that (warning: rant impending!) chairs are basically a rest stop for your body halfway between standing up and sitting on the floor. They're there because we're too tired, or achy, or whatever, to get all the way down to the floor and then all the way back up. They should be reserved for people who actually cannot get up from the floor. They inherently condone laziness. And believe me, I'm all for laziness here and there--but if I am trying to be lazy, I'm much happier lounging on the floor.
Whenever I'm at the office and not consulting with a patient--doing administration stuff, checking emails, researching, writing--I take the opportunity to take the floor. This afternoon I was doing some reading on Chinese herbal interactions before prescribing a formula to a patient, and it just made sense to spread out. Books, computer, coffee and me got cozy. I was definitely a lot more productive, and both my brain and body felt happy and healthy.