Canned Foods
As a general rule of thumb, "the more refined and processed a food is, the longer you can keep it past the expiration date,”Alan Aragon, M.S., previously explained to Men's Health. That applies to canned foods as well, provided they've been stored in a cool, dark area to minimize decay, says Amidor.
That said, you should watch out for signs of spoilage, which you’ll notice either on the exterior of the can or upon opening it, says Amidor. A bulging top or bottom, a leaky seal, dents, or rust on the can itself are usually a sign that you need to throw it out.
You should also take a good look at what's inside the can: “The signs of botulism are a bubbling and frothy texture at the top of the can that you don’t want to taste,” she says.
Dairy
Per the USDA, dairy products like yogurt, milk, and cheese are usually "safe until signs of spoilage are evident," says Amidor. In the case of milk, this can be up to five days past the sell-by date, while cheese (especially hard cheese) can last for a little bit longer.
Nonetheless, you should always check for signs of spoilage, such as bad odor or clumpy or chunky consistency.
Cereal and Other Grains
Per the USDA, it's usually OK to eat cereal, pasta, or cookies past the sell-by date, says Amidor (though they might taste slightly more stale). If it emanates a strong odor, however, or there are bites or tears in the package, that could indicate rodent contamination, and you should toss the package immediately.
Frozen Fruits and Vegetables
For the most part, it's totally OK to eat frozen fruits and veggies past their expiration date, even if they have freezer burn (that might affect the taste of the item, but it'll likely still be safe to eat.) That said, says Amidor, do not defrost an item and refreeze it: "that's a potential hazard for harboring bacteria," she says.