This is just a quick question, but basically:
Does an individual belong to a Rite in the way that he belongs to a "particular Church" in Catholicism? For instance, I will almost certainly be baptized in a Byzantine-Rite parish. If I move to another city and start attending a Western Rite parish, am I then considered WRO, bound by the WR fasting and prayer rules and not the BR ones, etc.? Or am I still a Byzantine just attending a Western parish until I make a formal transfer, like in the RCC?
The WR has a different Fasting routine?
It depends.
I visited the website of one WR parish and got the fasting rules they follow.
Abstinence means abstinence from meat only, with no restrictions on number, size, or timing of meals, and is practiced on Fridays.
Fasting limits the number, size, and timing of meals, but not the type of food, and is practiced on weekdays during Lent (along with abstinence), Wednesdays during Advent, and various special days (usually with abstinence).
By and large my research shows more fasting and less abstinence in the Western tradition, but no uniform rule for WRO.