What happens if you eat pizza left out overnight?

If your mind keeps juggling from one thought to another regarding that leftover pizza slice from last night, we got your back. In this article, we will be discussing the repercussions of having pizza left out overnight.

What happens if you eat pizza left out overnight

After you consume pizza left out overnight, your body becomes prone to several foodborne illnesses. According to the United States Department of Agriculture (USDA), food gets infected by bacteria after being kept outside for more than 2 hours. Consuming bacteria-infected food can lead to food poisoning and other health issues like dysentery and diarrhea. Initial symptoms of these foodborne illnesses include vomiting, stomach ache, nausea and other gastrointestinal issues.

Foodborne Illnesses: Symptoms and Diagnosis

The picture depicts a person having medicine after having a pizza left out overnight.

Foodborne illnesses like food poisoning are caused by eating or drinking contaminated food items and beverages. Food can get contaminated when left out for hours or when it comes in contact with unsanitized hands and utensils. Contamination of food and beverages mainly happens through bacteria, toxins, chemicals, and fungus.


The most common symptoms of food poisoning are nausea, vomiting, stomach ache, headache, weakness, and diarrhea. Depending on the type of infection, the symptoms take up to hours or even days to show up.


Consult your local doctor if you experience more than 2-3 of the above-mentioned symptoms. You might be asked to give a stool sample or blood test to examine the bacterial infection further. However, most of the cases can be treated at home by following certain measures.

Relieve your food poisoning with these measures:

  1. Hydration: Since your body loses lots of fluids due to vomiting and diarrhea, staying hydrated during food poisoning is the key. Keep having water and juices to stay energized.
  2. Cleanliness: Ensure that whatever you consume is washed thoroughly under cold running water. Also, wash your hands before consuming any food item.
  3. Avoid processed food: Anyone suffering from food poisoning must avoid pre-prepared food items like spreads, salads, cheese, and frozen food.
  4. Limit contact: If you have been vomiting or suffering from diarrhea, limiting your contact with people is better until the condition gets better. People diagnosed with food poisoning often end up spreading infection.

Frequently Asked Questions (FAQs)

1. Can you eat 1-day-old pizza that is not refrigerated?

United States Department of Agriculture states that any food item kept outside at room temperature should be consumed within 2-hours. Food that is kept outside for a long time becomes a breeding point for bacteria, chemicals, and fungi, which might further lead to foodborne sickness.

2. Is pizza safe to eat the next day?

Pizza is safe to eat the next day if you wrap it properly using a paper bag and keep it refrigerated. According to the U.S. Department of Agriculture, refrigerated food is safe to be consumed for up to 4 days.

3. How can you tell if pizza is bad?

The first sign of pizza going stale is its rough and dry texture. Moreover, you will be able to identify a strange odor and some mold growing over it.


We hope this article made it easy for our readers to understand the aftermaths of consuming unrefrigerated pizza that has been kept outside for over a night. Keep in mind the guidelines of the U.S.D.A and refrigerate food items by packing them correctly to avoid any growth of bacteria and toxins.

Stay tuned for more such food-related content!

Also Read: Best Chicago style pizza in Chicago

Shaleen Ashish
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