In the Roman Catholic Church, the first eight days of the Easter Season make up the Octave of Easter and are celebrated as Solemnities of the Lord according to *General Norms for the Liturgical Year and Calendar*. 
http://www.catholicculture.org/culture/library/view.cfm?id=5932#Easter

As each of those days is a Feast of the first order, fasting is clearly inappropriate.

Indeed, because *The fifty days from Easter Sunday to Pentecost are celebrated in joyful exultation as one feast day, or better as one "great Sunday,"* (ibid) it may be inappropriate to fast throughout the Easter season. St Augustine said of Sundays, "Fasting is set aside and prayers are said standing, as a sign of the Resurrection, which is also why the Alleluia is sung on every Sunday". (Ep. 55, 28: CSEL 342, 202)