"Jonathan Bloom, who runs the Web site wastedfood.com and is the author of the new book American Wasteland, [said] that, since the mid-nineteen-seventies, per-capita food waste in the United States has increased by half, so that we now throw away forty per cent of all the edible food we produce. And when we throw away food we don't just throw away nutrients; we also throw away the energy we used in keeping it cold as we lost interest in it, as well as the energy that went into growing, harvesting, processing, and transporting it, along with its proportional share of our staggering national consumption of fertilizer, pesticides, irrigation water, packaging, and landfill capacity. According to a 2009 study, more than a quarter of U.S. freshwater use goes into producing food that is later discarded."
...from an article in the New Yorker exploring the idea that, paradoxically, with increased efficiency comes increased waste. For instance, the use of CFCs instead of incandescent bulbs may lead us to save more money, but we use that savings to keep lights on longer, thus negating the savings. It's a fascinating concept explored in depth in this article (subscription required...sorry)