Here’s what you should know on why Catholics fast on Fridays

So why is it that the Church instructs Catholics to abstain from meat on Fridays (as well as Ash Wednesday and Good Friday), but gives a license for Catholics to eat fish? Sounds fishy to me!
But why Friday?”
Catholic faithful from the beginning of time has set apart Friday for special penitential observance by which they gladly suffer with Christ that they may one day be glorified with Him. This is the heart of the tradition of abstinence from meat on Friday and from then, that tradition has been observed in the holy Catholic Church.
Since it is believed that Jesus Christ suffered and died on the cross on a Friday, Christians from time immemorial have set aside that day to unite their sufferings to Jesus. This brought the Church to recognize every Friday as a “Good Friday” where Christians can remember Christ’s passion by offering up a particular type of penance.
For much of the Church’s history, meat was brought aside as a worthy sacrifice on account of its association with feasts and celebrations. In most ancient cultures meat was considered a delicacy and the “fattened calf” won’t be slaughtered unless there was something to celebrate. Since Fridays were thought of as a day of penance and mortification, eating meat on a Friday to “celebrate” the death of Christ didn’t seem right at all.
But why do we fast from meat, not fish?
The law of abstinence put into consideration that meat comes only from animals such as chickens, cows, sheep or pigs — all of which live on land.
Fish, in other words, are not in that same classification.
Fish is a different category of animal. In that case, salt and freshwater species of fish, amphibians, reptiles (cold-blooded animals) and shellfish are permitted.
“Carnis” is a Latin word used to describe what kind of “meat” that is not permitted on Fridays, and in a special way, it relates to “animal flesh” and never included fish as part of the definition.
Our current culture is much different from the ancient cultures as meat is generally considered the cheaper option on the menu and no longer has a cultural connection to celebrations. This is why many people are confused about the regulations, especially those people who love to eat fish and do not consider it as a penance.
Lastly, the intention of the Church is to encourage the faithful to offer up a sacrifice to God that comes from the heart and unites one’s suffering to that of Christ on the cross. Meat is brought up as the very basic penance, while the purpose of the regulation should always be kept in mind. For example, it does not necessarily give a person the go-ahead order to eat a lobster dinner every Friday in Lent.
The whole point is to offer a sacrifice that draws a person closer to Christ, who out of the love he has for us made the ultimate sacrifice a person can ever make.