The current discipline of penance for the United States, in addition to the general character of the Lenten season, is as follows:
Ash Wednesday and Good Friday are days of fast (limited to one full meal) and abstinence from meat.
Concerning the Good Friday fast, the Second Vatican Council teaches: “Let the Easter fast be kept sacred. Let it be celebrated everywhere on Good Friday and, where possible, prolonged throughout Holy Saturday, so that the joys of the Sunday of the Resurrection may be attained with uplifted and clear mind.”
The other Fridays of the season of Lent are also days of abstinence from meat, but each individual may substitute, for the traditional abstinence from meat, some other practice of voluntary or personal penance. This may be physical mortification, temperance, acts of religion, charity or Christian witness.
The obligation to abstain from meat binds Catholics 14 years of age and older. The obligation to fast, limiting oneself to one full meal and two lighter meals in the course of the day, binds Catholics from the age of 18 to 59. Those who are younger or older may freely embrace these disciplines; however, Lenten regulations should never endanger one’s health.
With regards to the obligatory days listed above, there are frequent questions about the degree of the seriousness of the matter. The teaching of Pope Paul may be simply paraphrased: The obligation to observe, as a whole or “substantially,” the penitential days specified by the Church is also serious. People should seek to do more rather than less; fast and abstinence on the days prescribed, and works of religion and charity on the Fridays of Lent, should be considered a minimal response to the Lord’s call to penance and conversion of life.