Dates on food labels are often the cause of confusion in many households. With a variety of terms listed on food packaging, consumers face a dilemma: toss or keep? A 2019 U.S consumer survey published in the journal Waste Management highlighted how consumers decipher different dates on food packaging. The expiration date or “use-by” date was mostly interpreted as a signal towards food safety, prompting consumers to discard products that have passed this date. The “best if used by” date was interpreted as a means of assessing the best quality of food. When the messages are misunderstood, it leads to a wastage of perfectly healthful food. An overwhelming 84% of individuals end up throwing away food that is past the listed date or even approaching the date. As a consumer and dietitian, I wanted to understand how to interpret these terms correctly and how they are regulated. If we can understand their meanings and use some reasonable judgment, we can work through the confusion and enjoy all of the wholesome food we purchase.


How are the dates regulated?

Almost all food products we bring in to our homes contain some date on the packaging. This includes meat, fish, and poultry; dairy products; packaged and canned foods; and refrigerated and frozen foods. It is important to know that these dates are not federally regulated. Federal regulations only require dates on infant formulas, which must contain a “use-by” date. Infant formulas lose essential nutrients over time and should be used by the listed date. Dating on other items is voluntary. Due to the lack of established federal standards, forty-one states have created their regulations and use various dating terms on food products. These dates do not necessarily determine if the product is still safe to use, rather it is a quality measure. Many manufacturers are starting to increase the use of the “best if used by” designation on food labels to standardize usage.


Dates can appear in different formats

Dates are usually listed in one of two formats. Open dating includes terms such as “sell-by,” “use-by,” and “best if used by” followed by a date with month, day, and year. Open dating is used for most products, including dairy items, meat, poultry, eggs, and baked goods. Closed dating (also known as coded format) is used on packaged, boxed, or canned items that are stored on shelves. They are a series of codes to indicate when the item was manufactured, not to express how long the product will remain fresh. This format is also helpful when manufacturers try to track their products during food recalls. These items may additionally contain dates in open format.


How do supermarkets keep track of expiration dates?

Tracking expiration dates on products is a tedious task for supermarkets. I remember witnessing it during a foodservice rotation as part of my dietetics training. There are several methods used for this purpose, with the most common one being the first-in, first-out stock rotation. Employees manually move the older stock forward on the shelves, and newer stock is moved to the back according to the expiration date. Quick selling items such as dairy, eggs, and bread are received multiple times a week, so they are generally checked more often. Expired items are removed, and items that are approaching the expiration date are sometimes marked down for quick sale. I wanted some insight into how stores make sure they do not carry expired items on shelves. I spoke with merchandise managers at a local grocery store and received brief information—they did not wish to discuss this topic in more detail. They have a series of codes for all merchandise the stores receive. These codes are used to keep track of the items based on how long they can be sold. When restocking, employees make use of these codes and the manual stock rotation method to determine which items need to be removed from shelves. Generally, the process is efficient, but items can be missed. When we pick up an item from the shelf, it is most likely suitable for purchase and not expired, but we must be proactive shoppers and check the dates before purchasing.


Understanding the terminology

Best if used by: Indicates the consumer should use the item by this date for the best taste and quality of the product. This does not relate to food safety, but consumers should monitor for signs of spoilage if using past this date.

Use-by: The date until which the product will be at peak quality. This does not relate to food safety. Perishables such as dairy products often contain this label. Except for infant formula, items can be used for up to one week after this date, provided they were stored correctly or refrigerated.

Expires on: Manufacturers use this date to indicate the anticipated best quality of the product. Do not purchase items past the expiration date. For items on hand, pay special attention to signs of spoilage, especially in dairy products.

Sell-by: Stores use this date to know how long they can sell the product. Ideally, stores should remove items that have passed the date. Consumers should monitor for signs of spoilage.

Freeze-by: The date recommended to freeze items to maintain the best quality. Once items are frozen properly, they can last for long periods.


Storage Tips

Product Category

Safe Storage

Signs of Spoilage

  • In sealed package refrigerated: 2-3 days
  • In freezer-safe package: 3-4 months
  • Slimy texture
  • Discolored appearance
  • Foul odor
  • Store in the middle of the refrigerator.
  • Whole (raw): in refrigerator 3-4 weeks past sell-by date
  • Hard-boiled (in-shell): in refrigerator up to one week
  • Hard-boiled (peeled): use the same day
  • Egg floats in cold water (indicates the egg is old, needs to be tested further)
  • Strong, sulfur-like smell
  • Foul odor immediately after cracking the egg
  • Must be refrigerated
  • Do not return unused portions into the original container
  • Tightly close lids and packets
  • Green mold
  • Curdled or slimy appearance
  • Foul odor
  • Sour taste
  • Gas formation
Canned foods
  • Do not purchase dented or rusted cans
  • Unopened cans should be stored in a cool, dry place
  • Transfer leftovers to resealable plastic bags or airtight containers
  • Keep the liquid along with the food – this preserves taste and texture
  • Store in the back of the refrigerator where the temperature is coldest
  • Swollen can
  • Foul odor
  • Cloudy liquid
  • Mushy texture
Breads and baked goods
  • Use airtight package or container
  • Store in a cool, dry place
  • Fruity odor
  • Cotton-like white spots
  • Green mold
  • Ropiness (yellowing, sticky texture)

Keeping track of the plethora of items in our pantries and refrigerators can be overwhelming. If we can gain a better understanding of the intended messages of dates on foods, it will significantly reduce the amount of wholesome food that is discarded. As a dietitian, I urge consumers to learn about proper food storage (what items go where, techniques to prolong food life, and safe food handling). Another important piece (my favorite) is to use leftovers or items which must be used up in quick recipes. Soups are an excellent idea for leftover meats or vegetables, bread can be diced and toasted for a crunchy soup topping or easy snack, and fruits can be used in smoothies, frozen treats, or jams. This is a fun way to get the family involved and enjoy delicious creations while minimizing food wastage.



Summaya Ali holds a Master’s degree in Nutrition from the University of Illinois and is a Registered Dietitian. She is excited to begin her career in Dietetics.