The Everydata of Expiration Dates.

We all have seen food expiration dates on cans, milk cartons, eggs, and just about every other food product in the grocery store.  But what exactly is a food expiration date, and where does the data come from that makes up these dates?

It turns out, as explained in this recent article from Jeff O'Heir at Yahoo.Food that there is far more to expiration dates than meets the eye.    Because, in fact, what most of us interpret as food expiration dates really aren't expiration dates at all.

According to the Food Safety and Inspection Service at the US Department of Agriculture, it turns out that most food is perfectly fine for consumption after the dates on the product.   In fact, the dates represent not expiration, but in most cases, the dates at which the product would be at its peak quality.   You can read about the different types of dates here.


A lack of understanding of what the underlying data is supposed to convey about food is a clear example of confusion as a consumer of data.  However, there is more confusion abounding as headlines about a recent study from Harvard's Food Law and Policy Center and the NRDC abound.  Here's a link to one story from a CBS news media outlet in Dallas: "Food Expiration Dates Cost You Money."   According to this article, "The NRDC estimates 9 out of ten Americans are confused by dates.  A family of four throws about $2000 worth of still edible food away every year."  I was curious about the source of this estimate, so I went and checked the public study on the Harvard blog website:

"This misinterpretation of dates costs money. Americans spend between $1365 to $2275 per household of four on food that is ultimately thrown out.2 While there is no research to indicate how much of that is due to expiration date confusion here in the U.S., a British study estimated that 20 percent of food wasted in British households is due to misinterpretation of date labels.3 If this same estimate were true for the U.S., it would mean that the average household is discarding $275 to $455 per year of good food because of confusion over date labels. "

So the actual study has two important caveats for you as a consumer of this data--the approximately $2000 worth of food thrown out is on all food, not just expired dates.  My first read would have been that the $2000 is on expired food.  And the extrapolation about date labels is based on a British study.   I don't know much about British food labeling, but surely an obvious question is how similar is the labeling practices in Britain.  It may well be that US consumers are confused by labeling, and it may be that Americans throw out food, but be careful to understand the actual magnitude and the sources of these numerical estimates.