Mother of two Jennifer McAdoo tosses any food past the date on the label so her family doesn't get sick.
"I don't want them to eat something that could harm them," she said. "I fear what might be seeping into the cans or what kind of bacteria is growing in there. I have no idea."
In fact, Americans chuck 160 billion pounds of food every year: An average family of four throws away $1,560 worth. But a lot of that food is perfectly good. In fact, a new study from Harvard finds that those "sell-by" dates are "confusing" and "misleading." In fact, that food may still be good for weeks, months, even years past the date.
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"People think these are expiration dates," said Emily Broad Leib, lead author of the study from Harvard Law School's Food Law and Policy Clinic. "They think if they eat the food after this date, they're going to get sick. But it's completely not true."
Broad Leib said food can be totally safe well past the date, from cereal to salad dressing, even eggs. She said "use by" or "sell by" dates on a product have "nothing to do with safety at all. It's just a manufacturer's best guess of when that food is going to be the freshest and at the best quality."
How do manufacturers come up with those dates? It's often unregulated, varying from state to state. In most cases, if you eat food past the date, you're not going to get sick.
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"According to countless food safety experts, the National Food Lab, there's not been a single instance of food-borne illness or food poisoning linked with people eating food after that date," Broad Leib said.
For McAdoo, who says she's going to hold onto her food longer, the news is a game changer. "I think you've definitely saved me some money," she said.
Now at least one member of Congress is proposing new legislation that would create a federal standard for food dating so the date on a bag of lettuce means the same thing as on a bag of lettuce in California.
—By NBCNews.com's Jeff Rossen and Josh Davis