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Experts say leftover food should be refrigerated quickly and then eaten within 3 or 4 days.
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  • A 19-year-old man became critically ill after eating his friend’s leftovers.
  • Improperly stored leftovers can make you seriously ill.
  • A few simple precautions can go a long way toward keeping you healthy.
  • Experts say leftovers should be refrigerated within 2 hours of cooking and eaten within 3 to 4 days.

The 2021 case of a 19-year-old man’s severe food poisoning is in the news again after a video describing the incident went viral.

The man ate leftover chicken, rice, and lo mein, and within 24 hours he was covered head to toe in a purple rash, his oxygen levels were dropping, and he was being transported by a medical helicopter.

And this isn’t the first time something like this has been reported.

Eating leftovers seems pretty innocuous — and sure, these are extreme cases — but every year, 1 in 6 people in the United States gets food poisoning.

Foodborne illness, indeed, is no picnic and it’s highly preventable.

So, how can you have your leftovers and stay healthy, too?

In these recent examples of foodborne illness, bacteria were to blame.

Paula Doebrich, RDN, MPH, a registered dietitian and the founder of Happea Nutrition, told Healthline that there are many types bacteria that can cause food poisoning, including:

Other pathogens besides bacteria can contaminate your food, too.

Penny Laurier, RD, a registered dietitian and review board member at 10 Minute Homemaking, told Healthline that you also need to watch out for viral and fungal infections such as:

“All of these pathogens can cause serious illness in humans, so it’s important to take precautions when handling and storing leftover food,” said Laurier.

The first step in avoiding food poisoning from leftovers is putting your food away quickly.

Wendy Lord, RD, a registered dietitian and nutritional consultant at Sensible Digs, told Healthline, “bacteria multiply rapidly when food is left out at room temperature.”

Lord added that bacteria grow when food is between 40°F and 140°F (4°C and 60°C).

Experts say that food should be stored within 2 hours of being cooked or within 1 hour if the ambient temperature is above 90°F (32°C).

“It’s important to note that not all food is created equal. Some foods will spoil faster than others. For example, dairy products and meat are more perishable than fruits and vegetables,” said Laurier.

So, it’s important for food to be refrigerated quickly, but what’s the right method?

“Leftovers should be stored in a glass or food-safe plastic container, or wrapped tightly in foil or cling wrap. The goal is to avoid exposure to the air and potential pathogens,” said Lord.

Doebrich agreed, adding, “[Leftovers] are best stored in small, shallow containers to allow for quicker cooling.”

As for how long you can keep your leftovers after they’re stored, it depends on the item.

In most cases, “leftovers can be stored 3 to 4 days in the refrigerator. They can also be stored in the freezer for up to 4 months,” Doebrich said.

If you know you won’t eat your leftovers within a few days, skip the refrigerator and put them straight in the freezer.

Eventually, you’ll want to take those leftovers out of storage and eat them.

Often that means using a microwave. There’s a right way to do that, too.

“It’s important to make sure that food is cooked evenly. Pockets of uncooked food can harbor bacteria and lead to food poisoning,” said Laurier.

A common challenge with microwaves is uneven heating.

“The food heats from the outside in. The edges of the dish may be hot, but the center could still be ice cold,” said Lord.

Covering and rotating the dish as you heat it can help to combat this.

Doebrich had another helpful tip: “Adding liquid can help kill harmful bacteria, as hot steam forms when the water is heated. Adding water to the dish will also allow for more even cooking.”

The most important part of reheating your leftovers is getting them to an internal temperature of at least 165°F (74°C). A food thermometer is the best way to make sure you’ve accomplished this.

In theory, you could reheat your leftovers multiple times, but it’s not recommended.

“Each time you reheat and cool down a food, the risk of foodborne illness increases. It is best to only reheat as much of the food as you think you want to eat and leave the rest stored safely in the fridge,” said Doebrich.

And for those times you’re just not sure if your leftovers are still good or not, Lord has some advice: “If in doubt, throw the food out.”