The Noble Pas Price

There is a commonly accepted custom to eat only pas Yisrael during the Aseres Yemei Teshuvah. Our bread, bagels, cakes, and muffins should all come from Jewish bakeries during the Ten Days of Repentance. That means that those who usually eat Dunkin’ Donuts muffins or bagels will have to switch to a different bakery for the week. Alternatively, you might want to consider purchasing a doughnut instead. Since doughnuts are deep-fried, they do not fall into the bread family, according to many poskim.
Let’s suppose that someone purchased an Entenmanns’s cake before Rosh Hashanah that will become stale if left until after Yom Kippur. Is it considered bal tashchis to discard it? Would the prohibition of bal tashchis override the custom of refraining from pas palter (bread from a non-Jewish bakery) during the Aseres Yemei Teshuvah? When I tell my children that they don’t have to finish everything on their plate, they argue that it would be bal tashchis to leave something over. They are essentially arguing the same point. Though it may not be healthy to consume all the food on their plate, perhaps bal tashchis directs them to.