Fasting

[1catholic]

If one did a poor fast on a fast day is it a mortal sin?

[cappie]

The Church used to prescribe very rigorous rules for the Lenten fast (including abstinence from all meat and eating only one meal per day). The current rules, however, are much more lax. Catholics are only required to fast on Ash Wednesday, the first day of Lent, and on Good Friday, the day that Jesus Christ was crucified. Anyone over the age of 18, but under the age of 60, should eat only one full meal on those days, although they can also have small amounts of food in the morning and the evening.

So these are the minimum requirements of a Catholic.

Those who are excused from fast or abstinence Besides those outside the age limits, those of unsound mind, the sick, the frail, pregnant or nursing women according to need for meat or nourishment, manual laborers according to need, guests at a meal who cannot excuse themselves without giving great offense or causing enmity and other situations of moral or physical impossibility to observe the penitential discipline.

The failure to fast on a particular fast day, or the failure to abstain from meat on a particular day for abstaining, if it is done deliberately and without a good reason, is a sin. But it is not a mortal sin, if the person does fast and abstain and practice self-denial on many other occasions. An act that is a substantially limited offense against the love of God, and the love of neighbor as self, cannot be a mortal sin. No substantially limited offense deprives the individual of the state of grace. No substantially limited offense deserves eternal punishment in Hell.

As long as you generally fulfill the positive precepts to fast, to abstain from meat, and to practice self-denial, then a particular failure of that obligation, on a particular occasion, cannot be a mortal sin. For you have generally fulfilled what the positive precept requires of you, despite a substantially limited failure on occasion.