"Enjoy by," "best before" and "sell by" labels on the packaging of US foodstuffs often have little connection to the date the food actually becomes spoiled, leading to a gross amount of perfectly good food being thrown away each day, a recent study by the Food Law and Policy Clinic at Harvard University reports. The study implicates wasteful and unregulated marketing practices and offers suggestions on how to better set food expiration dates in the US.

An estimated 40 percent of food in the United States goes uneaten and even the most conservative estimates peg American food waste at 160 billion pounds each year, the report states. Each American wastes 10 times as much food as the average consumer in Southeast Asia.

"The waste of edible food by consumers, retailers, and manufacturers poses a significant burden to the American food system. Wasted food costs consumers and industry money; squanders important natural resources that are used to grow, process, distribute, and store America's food supply; and represents a missed opportunity to feed the millions of food insecure households in the United States that are struggling to access healthy, affordable food. Misinterpretation of the date labels on foods is a key factor leading to this waste," according to the Harvard report, "The Dating Game: How Confusing Food Labels Lead to Food Waste in America."

The report calls for the removal from consumer view of any reference to a "sell by" date on food packaging, which the report's authors say communicates no useful information to the consumer once the product is brought home.

"'Sell by' and other date labels that are used for stock control by retailers should be made invisible to consumers," the report states. "Products should only display dates that are intended to communicate to the consumer."

The report also calls for the creation of a reliable and coherent food dating system, which would include elimination of quality-based dates on non-perishable, shelf-stable products, require a "freeze by" date where applicable, establish a language standard for quality-based and safety-based labels and ensure dates are in clear and predictable places on packaging. The report also calls for more transparency for interested consumers to learn about how the food's expiration dates are established.

Lead study author Emily Broad Leib told CBS reporter Diane Stern that food manufacturers pick dates that are protective over their brand. "Which is fine," Leib said. "It's just important for consumers to know that," she said, adding that there is no legal requirements for food date labels and that rather than pertaining to safety, the dates are often only the manufacturer's suggestion of peak quality.

"Sell by" dates are especially alarming because they present no consumer-pertinent information, yet the study found that 90 percent of consumers throw away food on the sell by date.

"Consumers need to take that extra minute to actually look at their food and smell their food and make an assessment," Leib said. "When we just rely on these dates and throw everything away after the date, we're leading to really high rates of food waste."