Has this food actually expired? Why label dates don’t mean what you think

An estimated 80 million tons of food goes uneaten in the US, accounting for roughly 149bn meals. Illustration: Rita Liu/The Guardian

When that bag of languishing lettuces starts to go a little limp or an old carton of yogurt is discovered in the depths of the fridge, most Americans will look for guidance from the date printed neatly on the food label.

But with the exception of infant formula, these labels are not actually a gauge of food safety. In the US, the marked dates are only intended to indicate quality and they are not regulated by any federal agency.