Quoted By:
Jovian P. Lang, OFM, in his book entitled Dictionary of the Liturgy (copyright 1989, Catholic book publishing Co. N.Y.) on page 11 writes under "Abstinence,"
Refraining from eating meat or food prepared with meat on certain days as commanded by the church, to remind us of Jesus' redeeming Death (on a Friday), to prepare for the celebration of certain feasts, to win heavenly graces, and to practice the virtue of penance (to atone for sin and for help in the firm purpose of amendment). "Days of abstinence" in the United States include Ash Wednesday, Good Friday and Fridays of Lent." On other Fridays of the year, all are exhorted to perform acts of devotion, self-denial, and charity in the spirit of piety and penance, and particularly for peace; abstinence from meat is especially recommended but under no obligation by law. Canon Law for the world prescribes abstinence on all Fridays (Canon 1251).
Mr. Lang acknowledges here that the Catholic Church does command to "abstain from foods" (1 Timothy 4:3). Catholic "Canon Law" (the official law of the Catholic Church) makes such a prohibition.
Canon 1251 - Abstinence from eating meat or another food according to the prescriptions of the conference of bishops is to be observed on Fridays throughout the year unless they are solemnities; abstinence and fast are to be observed on Ash Wednesday and on the Friday of the Passion and Death of Our Lord Jesus Christ. (The Code Of Canon Law: A Text And Commentary, p. 854, copyright 1985 by the Canon Law Society of America, published by Paulist Press)
Catholics are "bound" by this law of abstinence.
Canon 1252 - All persons who have completed their fourteenth year are bound by the law of abstinence
In other words, they are commanded to not eat meat ("or another food") on certain days. Worldwide, these days include Ash Wednesday, Fridays of Lent, Good Friday, and every other Friday of the year. For those in the United States, every Friday of the year is no longer obligatory.
