I recently had two days where I was eating two meals a day and also above my set caloric intake of 1500-1600kcal per day. This intake now seems to maintain my weight if I eat it in one meal and make sure that it is assimilated optimally.
But the last two days OMAD seemed somehow really hard and I gave in to eating lunch. But I guess I have learned a valuable lesson from this. The week leading upto those days I was not able to follow my meditation schedule. I had to start working much earlier than usual and did not meditate for my usual 60 minutes in the morning. And in the evenings I somehow did not have the motivation to do the full session.
So I ended up meditating for only 15-20 minutes a day and those sessions did not really get me into the desired zone of stillness, centeredness and clarity.
And now that I was able to meditate for longer again on Saturday, I could feel the full power again of a good meditation session. I put me right back into the content state of mind where I am not looking for the next thing to satisfy my longing and feeling of emptiness inside.
Therefore I think it is only possible for me to live on OMAD long term when I also stay in that mental state of inner content with what I have. Only then do I not want to seek satisfaction and numbing of my feelings through food.
I also experienced many of the bad side effects again of eating too many calories. I know those side effects well. As I have basically been eating a caloric surplus for many years. Even on a high carb whole foods vegan diet. Because I wanted to gain weight and build muscle I was always eating massive amounts of food. Comparing that to the amount I eat now, that seems enormous and totally unnecessary and possibly unhealthy.
So the bottom line is: to live on OMAD without any feelings of deprivation and suffering you have to grow mentally and spiritually. Therefore I think it is precious to have a daily meditative practice set in place that is followed with rigidity and if possible without deviation.
In my experience, skipping the daily meditation quickly sets one back into a state of restlessness and unhappiness which creates suffering if one cannot immediately stop small feelings of hunger one perceives on OMAD.
Especially temptations become harder to resist as one is not in a centered state of mind. Thoughts amount uncontrolled to a "rational" conclusion why it is okay for one to deviate from the protocol of eating one meal a day. With enough mindfulness gained through daily meditative practice one can see the root and beginning of those thoughts. And see that they are ultimately groundless.