The Church teaches that Catholics in good health
are to observe the following practices during Lent
unless for some serious reason they are unable to do so.

From the United States Conference of Catholic Bishops:

“Ash Wednesday and Good Friday are
obligatory (mandated) days of fasting and abstinence
for Catholics. In addition, Fridays during Lent are
obligatory (mandated) days of abstinence.
The norms on fasting are obligatory from age 18
until age 59. When fasting, a person is permitted to eat
one full meal, as well as two smaller meals that
together are not equal to a full meal. The norms
concerning abstinence from meat are binding upon
Catholics from age 14 onwards.”