Is there a medical dispensation formally allowed from Lenten fasting in Catholicism? Today, 10 February 2016, begins the observation of Lent in the Catholic Church, and indeed in much of Western Christianity. Catholic rules for the observation of Lent include the requirement for adults to fast (that is, to reduce one's eating) on certain days:

Abstinence from meat, or from some other food as determined by the Episcopal Conference, is to be observed on all Fridays, unless a solemnity should fall on a Friday. Abstinence and fasting are to be observed on Ash Wednesday and Good Friday.
To the law of abstinence those are bound who have completed their 14th year of age. To the law of fast those of the faithful are bound who have completed their 21st year and up until the beginning of their 60th year.

(Apostolic Constitution Paenitemini, Paul VI, 1966; norm IV)

The law of abstinence binds those who have completed their fourteenth year. The law of fasting binds those who have attained their majority, until the beginning of their sixtieth year.
The conference of bishops can determine more precisely the observance of fast and abstinence as well as substitute other forms of penance, especially works of charity and exercises of piety, in whole or in part, for abstinence and fast.

(Code of Canon Law, canons 1252–1253)

Amended: &quot;... the age of fasting is from the completion of the twenty-first year to the beginning of the sixtieth&quot; (Paenitemini, norm IV) is amended to read &quot;‘... the age of fasting is from the completion of the eighteenth year to the beginning of the sixtieth' in accord with canon 97.&quot;

(Complementary norm to Canon 1253; U.S. Conference of Catholic Bishops)
Thus, although the general rule of fasting binds everyone who has &quot;attained their majority&quot;, the local episcopal conferences can modify this rule, and the U.S. bishops have determined that &quot;their majority&quot; means from age 18.
I have heard, however, that this requirement is dispensed (waived) for those for whom it would be a medical hardship. But I can't find a reference to such a dispensation either in canon law or in anything published by the USCCB.
Is such a medical dispensation formally allowed for by the Church?
The USCCB website has several questions and answers about Lenten observances.
The last one of these is:

Q.  Are there exemptions other than for age from the requirement to fast on Ash Wednesday and Good Friday?
A.  Those that are excused from fast and abstinence outside the age limits include the physically or mentally ill including individuals suffering from chronic illnesses such as diabetes.  Also excluded are pregnant or nursing women.  In all cases, common sense should prevail, and ill persons should not further jeopardize their health by fasting.