Expiration Date 101

Use by, sell by or best before…confusing, right? Next time you're trying to make sense of a food label, remember these guidelines from Lindsay Baker, RD, LD, a registered dietitian and food safety expert in Augusta, Georgia:

• Sell by most often is grocer terminology, letting the meat or dairy clerk know when to swap out stock. While you can normally safely eat a food a few days after a sell-by date, it's not recommended to go much beyond it.

• Best before refers to quality and taste standards. The length of time that food is good after this date depends on the product. Refer to the guidelines listed below for specifics on each food type.

• Use by is more of a hard-and-fast rule indicating that it is not safe to consume a product beyond the stated date.

And yet, in some cases, according to Shari Portnoy, MPH, RD, a registered dietitian and food safety expert in New York City, it can be all in our heads. "The expiration date can have an impact on how we taste the food," she says. "A study at Cornell University that was reported in the Journal of Food Science showed that people who ate yogurt on the day it was said to expire said the yogurt tasted bad. Others who ate the same yogurt but didn't see the expiration date enjoyed the food without claims of spoilage."

Ultimately, it all depends on the type of food. Read on to find out specifics.