Nothing lasts forever, and that's especially true when you're talking about food. Sure, expiration dates are overused, difficult to judge and don't actually mean that much, but food doesn't stay fresh or at its peak for eternity. While we may be stating the obvious, we also know that people need reminding every once and a while of seemingly obvious food facts. Newsflash: your spices expire, and that's not the only thing hiding in your pantry that may be ready for a replacement.

Note that we are in no way encouraging you to throw perfectly good food away. In fact, we applaud recent efforts across the food world to waste as little food as possible by using the whole vegetable, using bones (ahem, broth) and less popular parts of the animal, freezing as much as you can and employing tips to keep produce fresh. We encourage composting and thinking twice before throwing anything in the trash.

We merely want to point out that certain foods, probably hiding in the depths of your cupboards, might not be as fresh as they once were. If you're moving, perhaps you don't need to travel with these items, and if you're getting ready for spring cleaning (wishful thinking), you might want to give these foods a second look.

Here are seven foods that expire way before you think they do. Unless otherwise noted, these estimates pertain to food stored in the pantry. And the timelines are simply guidelines that may change according to storage methods and climate.

1. Flour

6-8 months for all-purpose, opened or unopened
4-6 months for whole wheat, opened or unopened

Think that flour in your pantry is good after a year? Think again. Flour's lifespan is closer to half a year. It can go rancid or get infested by insects, and you don't want any of that in your baked goods. Make sure to store flour in a cool, dry place, as humidity exacerbates spoiling. Here's a tip: you can keep flour in the fridge or freezer to protect if from humidity!

2. Spices

6-12 months, opened or unopened

This is a biggy. People tend to assume spices last forever -- or if not forever, at least a few years. According to Karen Page, who wrote The Flavor Bible, spices only last between six and 12 months. While expired spices may not be harmful, they'll lose their strength and won't have the same impact on your dishes.

3. Brown Rice

6-8 months, opened or unopened

You might assume that brown rice lasts indefinitely, but you'd be wrong. Brown rice only lasts between six and eight months. White rice has a longer lifespan, four to five years according to Eat By Date, and indefinitely, if stored properly, according to Good Housekeeping. Brown rice, however, can go rancid.

4. Nuts

9-12 months for almonds
6-9 months for cashews
6-9 months for peanuts
6 months for pecans
3 months for pistachios
1-2 moths for pine nuts

Depending on the nut, you could be looking at a very short lifespan. Unopened nuts will last longer, depending on the kind. It varies from nut to nut, and if you're worried you're not going to get through all your nuts fast enough, store them in the freezer!

5. Cereal

4-6 months opened
6-8 months unopened

Buying cereal in bulk? Not so fast. Most likely your cereal will just go stale and not be harmful to eat, but it can go bad if stored in a humid climate and exposed to moisture.

6. Ketchup

Up to 1 year for an opened bottle in the fridge
1-2 years unopened in the pantry

You might want to toss that bottle of ketchup that's been in your fridge for years. It may still be safe to consume, but if the liquid separates from the solid matter, it's not going to taste great. Save your hot dogs and burgers!

7. Certain Cooking Oils

3 months for grape seed oil, opened or unopened
6-8 months for opened sesame oil, 1 year for unopened
4-6 months for opened truffle oil, 1 year for unopened

Not all cooking oils are alike. While olive oil lasts up to two to three years, grape seed oil only lasts three months! Eat By Date has a complete list of different oils with their different expiration dates, according to where they're stored and if they're open or unopened.