Should I clear my plate?

Clearing the plate has been an advocated act in my upbringing and an act that I faithfully sticked to. I had believed in that one should always clear the plate for various ethical reasons, e.g. not wasting social resources especially when many people around the world still starve, or simply saving some money for my family by wasting less.

Then my faithful strategy was penalized by the adversary in the dining table: when I was in the primary school, my mom, who believed I was overly lean and knew my clearing-plate strategy, deliberately cooked much more than the family could normally take every time. Then I quickly became over 2x heavier because I had to ate up everything.

Until then I realized my strategy was so vulnerable in terms of my own utility. While I tried to act otherwise, I also tried to un-justify it, i.e. maybe clearing our plates is not that morally laudable. Indeed, conditioned on an excessive amount of food is served, taking a comfortable amount maximizes our (or just my) utility, because gaining more weight than wanted has a long-term effect and potentially large cost on emotion and time (to lose weight). If you’re in a restaurant, they deal with waste anyway, so you add little marginal cost on them and on the society if the waste is dealt with properly.

It is however not saying we give up on saving food. I now believe the best practice is to ask everyone follow a good ordering (or cooking if at home) strategy:

• Estimate roughly how much you (or the whole party) can comfortably consume;
• Order (cook) 80~90% of your estimate;
• Have a running estimate of how much you’ve ordered based on the served dishes;
• Order more if you underestimated.

Then you save everything including your money, the edible resources of the society, the resources for decomposing waste, etc. It’s also always better to eat less than eat more, as you can obviously have snacks / desserts afterwards.