If you want to go ahead with what you suggest here āeat lunch at 12 and then receive the Eucharist at the 7:30 pm Mass, and then have dinner at around 9ā go for it. Or again, try it only on certain days.
There is nothing āwrongā with following what you say you could do here, other than the missing main component.

The issue is WHY.Just considering the number of hours you donāt eat before reception of Eucharist is the juridical approach which isnāt the objective for us.
As is emphasized in the Latin Church, fasting is part of the three part direction in Great Lent, the other being prayer and almsgiving/works of charity. All of this is for our benefit in helping restore us to our true selves and restore us into communion with the most Holy Trinity.
It sounds like in the years you were yourself part of that Russian Orthodox parish before you left Orthodoxy in college you and your family missed out on catechesis on the meaning and purpose of fasting from the Eastern perspective.
If you want to understand WHY you would fast, from our perspective, again, I encourage you to listen to the interview with Fr. Moses, also to some of the programs that come up under fasting on
Ancient Faith Radio. I think Fr. Loya also covered aspects of fasting on
Light of the East March 8, 2011 #337: āThe Great Fast Continuesā.
Do some reading. There is a great deal of excellent material available on WHY we fast. As I mentioned I really love Fr. Schmemannās writings. Hereās
one piece on the OCA site,
another three of writings from my parish āā¦The least important (but most visible) aspect of this fasting is a change in the quantity and quality of food:ā¦ā
āThe fast of Lent has no advantage to us unless it brings about our spiritual renewal. It is necessary while fasting to change our whole life and practice virtue.ā
St. John Chrysostom.
If it hasnāt already been said, we begin Great Lent singing āLet us begin the fast with joy! Let us prepare ourselves for spiritual efforts!ā It is a joyful practice in a joyful time of preparation and anticipation, as are the other 3 major fasts in the Eastern liturgical year.