Until relatively recently—within the past 50 years, say—no one had to be told not to waste their food, and certainly not as an ecological or even public issue. It was simple common sense: Who the hell would throw away something so obviously precious? It would be like tossing money into the street. As documented even in the title of Jonathan Bloom's American Wasteland: How America Throws Away Nearly Half of Its Food (Da Capo, 360 pages, $26), this situation has markedly changed.

As the cost of food has shrunken relative to income—and as food came to be taken for granted as a convenience rather than as a difficult-to-provide, essential domestic resource—we became less worried about letting food spoil in the fridge, slosh down a disposal or sit abandoned on a restaurant table. Our eyes got bigger than our stomachs. When even fine dining comes to us as easily as slop dumped from a bucket, we all become pigs; that's part of the moral of the Boston-based journalist's book. It's the dark side of all those luxury food shows on TV.

But it's not just that simple. Those very industrial agricultural efficiencies that have made food so cheap also make us inefficient in getting it to the table. Because food is shipped so far from farm to store, farms are left to toss tons and tons of produce that might not be able to make the trip; supermarkets, bent on displaying an abundance of food, toss tons more as the food withers on its shelves. The abundantly cornucopia'd food porn of a Whole Foods shelf is also a result of relentless culling; that perfectly round, spot-free tomato at your grocery store masks tens of perfectly edible, perhaps even tastier tomatoes left behind. About 10 percent to 20 percent goes lost at each stop on the chain, from the farm to the transport to the store to a restaurant or your own twilight zone of a refrigerator.

Where American Wasteland really shows its value as a book, however, is not in its diagnosis but its solutions. At the level of the farm and store, Bloom's advocacy extends mostly to gleaning (an age-old, bible-recommended practice wherein the poor pick the harvest remainders as food), supermarket food-bank donations and "pre-dumpster" gleaning (a practice favored by Portland's own New Seasons markets, where unsalable-yet-edible food is placed in a separate box from the dumpster, for urban scavengers.) Likewise, Bloom shows any number of home and restaurant solutions for reducing waste, especially useful since neither bottom line is very far from the floor these days. (An average four-person household dumps about $40 of food each week, by his estimate.)

But still, the basic message, aside from money-saving, is simple: Don't throw away food while others starve. Or, if you prefer utter non sequitur:  “Clean your plate. There are kids starving in Africa.”

GO: Jonathan Bloom reads from American Wasteland at Powell's on Hawthorne, 3723 SE Hawthorne Blvd., 228-4651. 7:30 pm Thursday, March 10. Free.