I don't know about after, but before, yes, we are still obligated to follow this discipline. From what I understand, it is in place to help us properly prepare ourselves to receive Christ by fasting. However, there are cases in which fasting is not required.
[quote=http://www.ewtn.com/faith/teachings/euchb2a.htm]370, What are the current rules for fasting before Holy Communion?
(a) For many centuries the Church commanded a strict fast from midnight before one could receive Holy Communion. However, in the 1950's Pope Pius XII introduced a much more lenient form of fasting before Holy Communion in order to give Catholics an opportunity to receive Holy Communion more frequently.
(b) Pope Pius XII also allowed the celebration of afternoon and evening Masses every day, when the spiritual good of a considerable number of the faithful requires it. It is the right of the bishop of each diocese to decide when such Masses may be offered in his diocese.
(c) Paul VI further reduced the fasting requirement after the Second Vatican Council, requiring only a one hour fast from all food and drink (excluding water). This may be reduced to 15 minutes for those who are sick or for other important reasons. This is the practice currently in force.
- When may Holy Communion be received without fasting?
Holy Communion may be received without fasting when one is in danger of death, or when it is necessary to save the Blessed Sacrament from insult or injury.
(a) Ordinarily the danger of death comes from sickness or injury. But it is not necessary that a person be in danger of death from sickness in order to receive Holy Communion without fasting. The danger of death may come from some other cause. A soldier, for example, who is about to go into battle or a person about to be executed may receive Holy Communion without fasting.