In 1953 Pope Pius XII loosened the Eucharistic fast for Masses celebrated after noon: “Priests who say afternoon Masses, as well as the faithful who receive Holy Communion at these Masses, may, at the meal which is permitted up to three hours before the beginning of Mass or Communion, take with due moderation the alcoholic beverages which are ordinarily taken at meals, (for example, wine, beer, and the like). They may not take strong liquors. With regard to beverages, which can be taken before or after the above-mentioned meal, up to one hour before Mass or Communion, everything alcoholic is excluded.” ( 13Christus Dominus)
Then, in 1957, he loosened the fast even further: “Priests and faithful, before Holy Mass or Holy Communion respectively, must abstain for three hours from solid foods and alcoholic liquids, for one hour from non- alcoholic liquids. Water does not break the fast.” ( 2Sacram Communionem) He also said that “the fast must be observed for the period of time indicated in n. 2, even by those who celebrate or receive Holy Communion at midnight or in the first hours of the day.” ( 3Sacram Communionem)
In other words, a three-hour fast before receiving Holy Communion was the “traditional” fast at the time of Vatican II. Fasting from midnight on is great, if you can do it – maybe even meritorious, I don’t know – but Pope Pius XII had loosened that to only three hours.