Abstinence from meats is to be observed by all Catholics 14 years old and older on Ash Wednesday and on all Fridays of Lent.
Fasting is to be observed on Ash Wednesday by all Catholics who are 18 years of age but not yet 59. Those who are bound by this may take only one full meal. Two smaller meals are permitted if necessary to maintain strength according to one’s needs, but eating solid foods between meals is not permitted.
The special Paschal fast and abstinence are prescribed for Good Friday and encouraged for Holy Saturday.By the threefold discipline of fasting, almsgiving and prayer the Church keeps Lent from Ash Wednesday until the evening of Holy Thursday. All of the faithful and the catechumens should undertake serious practice of these three traditions. Failure to observe any penitential days at all or a substantial number of such days must be considered serious.
(Archdiocese of Chicago)