The discipline of Eucharistic Fast has changed through the ages. The more ancient Tradition was to abstain from food or drink (even water) from midnight. But in these days, there were no such thing as afternoon Masses. The latest a Mass could start was 1:00pm.
This discipline was alleviated under Pius XII to render Mass attendance and the reception of the Holy Eucharist easier in the modern life. Traditional Catholics usually follow the laws as they were under pope Pius XII. After his death, the situation of the Church was not normal any longer, because the Church was under the control of her enemies and many of the laws of the Church were destroyed. This is why we should keep the disciplines of the Church prior to the election of John XXIII.
By the Apostolic Constitution Christus Dominus (1953), pope Pius XII kept the Eucharistic Fast from midnight but ruled that water does not break the fast. He permitted evening Masses on certain days. He allowed sick Faithful and Priests to take something under the form of a beverage (no solid food or alcohol though) any time before Mass if needed. Pope Pius XII also allowed the Faithful exhausted by a tiring work or by the late hour at which Mass is celebrated, even though they are not sick, to take some beverage before Mass (no solid food and no alcohol), provided that they fast from liquid other than water at least one hour before receiving Holy Communion.