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Victor Holguin/Demand Media

Fresh, hot popcorn is a tasty snack that is low in calories compared to other snacks. A cup of oil-popped microwave popcorn contains only about 64 calories per cup, according to SELFNutritionData.com. But popcorn can be less than satisfying when it grows cold. Rather than popping up a new bag, you can warm your popped popcorn so it is hot and fresh-tasting again. Depending on your preferences, you can do this either in the microwave or in the oven.

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Victor Holguin/Demand Media

Place the cold popcorn into a microwave-safe dish. Cover the dish lightly with plastic wrap.

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Victor Holguin/Demand Media

Microwave the popcorn for 20 seconds on high. This should be enough to reheat it and make it enjoyable again.

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Victor Holguin/Demand Media

Heat your oven to 300 degrees if you do not want to use the microwave. Put the popcorn into an oven-safe dish and place it into the oven.

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Victor Holguin/Demand Media

Bake the popcorn until it is heated to your liking. This should take 5 to 10 minutes.