Is Rabeinu Yonah at all encouraging wasting any food?

Question

Rabeinu Yonah discusses one of the ways of repentance as leaving a little food over after the meal.

אך בעת מאכלו ועודנו תאב לאכול יניח ממנו לכבוד הבורא מתאוותיו, ואל יאכל כפי תאוותו. ודרך זה ימנענו מחטוא, ויזכרנו אהבת הבורא יותר מתענית אחד בשבוע. כי זה בכל יום תמיד מדי אכלו ומדי שתייתו יניח מתאוותו לכבוד הבורא

It seems to me the context he intended was a meal where one would save the food for a later date. My question regards how this practice could be observed in a situation where one could not save the food. Perhaps one receives stipend food in a context where saving is not an option. (Office, army, hospital etc.) wWould Rabeinu Yonah then rather wasting of food or fulfilling this edict? Or perhaps only to fulfill it when saving is an option - what if it never becomes an option (and I am too weak to fast, but I want to overcome my desires of food etc.)?

Answer 1

Rabbeinu Yonah is not recommending we waste food. He is recommending we utilize some of each meal to practice self-restraint. Developing our ability to say "no" to a physical desire is no less important of a usage than consuming food to sustain our bodies and keep on living. After all, if we are weak in the ability to control such desires (taavos), how often will we make the wrong decision when having to choose between physical pleasure and doing the wrong thing?

Answer 2

The Gemora in Eiruvin 53b mentions this practice of leaving food at the corner of the plate for the shamash (attender) to eat his portion (also see Shulchan Aruch OC 170,3):

אמר רבי יהושע בן חנניה...פעם אחת נתארחתי אצל אכסניא אחת עשתה לי פולין ביום ראשון אכלתים ולא שיירתי מהן כלום שנייה ולא שיירתי מהן כלום ביום שלישי הקדיחתן במלח כיון שטעמתי משכתי ידי מהן אמרה לי רבי מפני מה אינך סועד אמרתי לה כבר סעדתי מבעוד יום אמרה לי היה לך למשוך ידיך מן הפת אמרה לי רבי שמא לא הנחת פאה בראשונים ולא כך אמרו חכמים אין משיירין פאה באילפס אבל משיירין פאה בקערה

So usually the attendant would eat the leftovers in those days (though nowadays with all our Abundence thank G-d people no longer need to rely on such rations and every attendant has their own private portion), and there was no issue of bal tashchis wasting food. To the contrary giving food to the more deprived.

But if there wasn't any buttler available or if the buttler didn't want to eat leftovers that day, then Rabeinu Yonah is saying to keep the practice leaving food on the side and not to finish it just because its there,as people are used to giving themselves larger portions than they need for the benefit of the attendant. On these occassion it is quite clear that one would try save food for later, or when perishable find someone else to give leftovers to as the whole Minhag stems from giving the leftovers to others.