Box of cereal from Colorado Walmart expired in 1997

March 9 (UPI) -- A Colorado father said he bought a box of cereal from Walmart this week and ate an entire bowl before discovering it had expired -- 21 years ago.

Josiah and Anthea Carelse of Lakewood said they bought the box of Quaker 100 Percent Natural Granola cereal from the Walmart in Littleton on Monday and they later sat down to eat some of the breakfast food.

Anthea Carelse said she took only a couple bites before deciding something was off about the taste, but Josiah ate an entire bowl.

"I just started eating and thinking, 'It just tastes funny. It must be OK,'" Josiah Carelse told KMGH-TV.

The couple said it wasn't until after Josiah finished his bowl that they noticed the "best by" date on the box.

"It looks like February 22, 1997," Anthea Carelse said.

The couple went online and verified the box did not look like Quaker's current design for the cereal, and the product they purchased indeed appeared to be a full decade older than their 11-year-old daughter, Layla.

"We just grabbed this off the shelf and yeah... 21 years old," Josiah said.

The United States Department of Agriculture said "best by" dates are voluntarily printed by manufacturers.

"Manufacturers provide dating to help consumers and retailers decide when food is of best quality. Except for infant formula, dates are not an indicator of the product's safety and are not required by Federal law," the agency said.

The Carelses said they plan to return the box of cereal to Walmart.

A Walmart representative said the company is investigating the matter.