Reason, the virtue of temperance, and good judgement of conscience can guide one in ones eating. Though it is to be noted that what is contrary to temperance for one is not for another and as at least one Saint reminds us–this is a area that is a difficult one where many struggle.
Also note that often one is dealing with venial sin --not serious (an example of serious gluttony is loosing ones reason via being drunk…). It is important to note this for some get confused on this subject.
We should seek to live by virtue here and to eat reasonably…
Individual acts of overeating…intemperance (gluttony in this sense) are ordinarily a “venial matter” for
venial sin…
(Now certain uncorrected habits that cause at least in the short term -serious problems -can become grave…like perhaps your doctor tells you if you keep eating 7 pieces of cake a day you will seriously harm your health or drop dead in three months…)
A confessor can assist one.
CCC
1809 Temperance is the moral virtue that moderates the attraction of pleasures and provides balance in the use of created goods. It ensures the will’s mastery over instincts and keeps desires within the limits of what is honorable. The temperate person directs the sensitive appetites toward what is good and maintains a healthy discretion: “Do not follow your inclination and strength, walking according to the desires of your heart.” Temperance is often praised in the Old Testament: “Do not follow your base desires, but restrain your appetites.” In the New Testament it is called “moderation” or “sobriety.” We ought “to live sober, upright, and godly lives in this world.”
scborromeo.org/ccc/p3s1c1a7.htm#1809
Let us live more and ore a life of temperance --even amid the feasts that are now upon us (as the Blessing of Easter Foods reminds us!). Now of course temperance on feasts can look different then temperance on normal days -but still it is to be temperance.
Christ is Risen!