As is true of many people growing up in the US, I was encouraged to always clean my plate (encouraged is putting it mildly -- I remember being required to still be sitting at the dining table at 3am (and even longer if "necessary") because I hadn't cleaned my plate). The general principle of not wasting food is a good one -- the dangling of "there are starving people in xxx" is NOT a good one as the reason for people starving in parts of the world is political and not economic (cleaning my plate, or not, would make no difference).
If I took food onto my plate and then told "take what you want, eat what you take" then that would also be reasonable. I would learn to take only what I was hungry for and would eat and there would not be any immediate wastage. (Eventual wastage was/is dependent on how much was left at the end of the meal and whether there were unplanned meals where leftovers were a strong source of food.)
Having others put food on my plate and then being required to eat it was NOT a good principle. It primarily taught me to ignore my feelings of satiation. There was no such thing as being "full" or "content" as long as there was still food left. This system of superfluous portions continues into the present day with "supersizing" and eating-out portions in general. There is always the possibility of bringing food home but, honestly, how many times does it go home to be later thrown out?
Being able to overeat has been a source of status in many societies in the past. Actual overeating, however, has not been, and is not, healthy for anyone.
This principle also comes true in business areas. It's always tempting to get a lot of something because you can get it for less per unit. Buy 50 for $100, buy 100 for $150. But there are hidden costs to buying more than you currently need. Storage, logistics in general. Yes, you may save money (even allowing for hidden costs) but might that extra capital being held as storage of an item be more useful for something "now"? This is the primary driving principle for "just in time" deliveries of materials. When this is combined with primary storage working with multiple consumers then both types of savings can take place -- quantity savings for the primary storage location with "just in time" savings of space and capital for the consumers.
As personal consumers of food, we also tend to put the surplus into storage. That storage affects our health and our waistlines. It is difficult to average out food consumption and purchasing to create an optimum "no extra, no waste" situation. It is more difficult with one person than two, more difficult for two people than for five. There is also the need to balance need versus cost. If buying four cucumbers costs only 25 cents more than buying two, then buying four is the obvious bargain, correct? But what if I said that you can only reasonably use two cucumbers before the others go bad? You end up saving 25 cents (and storage space) by NOT buying the larger quantity.
"To waste or to waist". My childhood training taught me one set of values. My knowledge, as an adult, tells me otherwise. But that doesn't make it easy to change. It can also be difficult, in business, to pass up bargains where the real value received does not match up to the price. As always, all aspects of a transaction -- or transaction's journey -- must be considered.
