[ Uposatha ]
Preparing for Uposatha
V: In preparation for Uposatha, I decided to shift my "one meal per day" from early evening to late morning. Something interesting happened. Even though I was not the least bit hungry in the morning, I ate anyway. By evening, even though I'd already eaten, I was still feeling hungry. I nevertheless resisted eating for that evening (wasn't easy lemme tell ya), thinking I'd be hungry the next morning and all would adjust accordingly. Not so. I woke up not the least bit hungry once again! I still ate, though not hungry and again, hungry in the evening! What is this anyway? It appears that my body's in some kinda rut but what's most interesting is that it seems to be causing the "desire" to eat. Or is it the mind?
This practice will teach you a huge number of things about the interrelationship of habits and desires. One of them is as you suggest.
I also have been eating one meal a day for many years. My practice has been to eat before or at noon. So my experience is the converse of yours: when on the rare occasion I do eat a late meal (as with Thanksgiving with the relatives) I feel it! Ohgha! The juices are just not prepared. They have gone to sleep for the day. And the meal just sits there. So there is definitely a physiological aspect to this.
I mention in the discussion in The Pali Line about eating one meal, that after a while of doing this the body seems to adjust perfectly and one can even become overweight eating one meal. My conclusion is that we eat more than we need to and that whatever is more than we need to eat is just simply and literally, storing up . . . um . . . DUKKHA.
Fat is Death
Wrapt Round You
Remember that the thought that should accompany our eating is: "With this moderate eating practice I will bring old kamma to an end and set going no new kamma." There are few places where the manner of bringing kamma to an end is quite so clearly evident as in abstaining from a meal. First you see the desire created by the habit, then after a time, you see that there is no more desire, and there was never a need in the first place. (And you can hear your stomach and body thanking you! Oh Thank Gah! He took a day off!)
What is at work is Downbound Confounded Rebounding Conjuration. Sensation produces the memory of past eating, those memories come to mind and dwelling on those memories desire arises. Acting on that desire we move around and prepare food and eat it. A couple of days later we experience one or two lumps of kamma as a consequence, but that is only the physical aspect (and only part of that other aspects being the way the body habituates to food consumption patterns; and the diseases that result from waste food products accumulating in the body); the mental aspect is buried behind the habit and does not even come to the surface until the habit is broken when we discover that there was a whole matrix of desires and memories involved.
A huge benefit of doing this Uposatha practice just even as a scientific experiment.