Trending
Steam Room Vs Sauna : Which is Better For You? What is Quantum Nutrition: Food and Benefits What Happened When I Finally Fixed My Burpee Form? Salsa Inglesa : Nutrition Facts And Health Benefits Keto Diet and its Unexpected Effectiveness What is Grapevine Exercise And How to Do Hip Thrust Mistakes I See Most Often—and How You Can Fix Them for Better Glute Gains Take Care of The Skin With This 6 Easy Body Skin Care Tips Night Leg Cramps : Reason And Proven Home Remedies Top 10 Reasons Why You Should Try a Plant Based Diet Yoga for Back Pain: How Yoga, Qi Gong, and Tai Chi Helped Me Find Lasting Relief Triangle Mudra: Discover the Benefits and Learn How to Perform It Think Washing Chicken Is Safe? Here’s Why It’s Actually Dangerous for Your Health How I Used Neem Oil for Lipoma: My Honest Experience (What Worked & What Didn’t) Top 10 Yoga Asanas for Lipoma How To Take Care of The Heart? Learn From Cardiologist Best Way to Increase Platelets Count in Dengue Chinmaya Mudra: Benefits, Side Effects, How To Do and Precautions What To Wear To The Gym For Male, Female and Fat How Does Insulin Injections Work in Diabetes? 5 Magical Quantum Exercise With The Power of Yoga Bear Plank: One of the Best Core Exercises Uveitis Eye Exercises: Effective Techniques for Managing Inflammation and Enhancing Vision How Yoga Sutra 1.1 Helped Me Begin My Journey of Mindful Practice Lucid Dream as a Bridge Between Realities 7 Evergreen Exercises for Flat Tummy and 6 Pack Abs Are Pizza Rolls Healthy: 10 Brilliant Ideas To Make It Healthier The Diet of a Professional Football Player My Experience With Sat Kriya: Benefits, Precautions, and the Right Way to Practice Bumbu Rum : Amazing Facts Hyperbolic Diet- A Magical Diet for Weight Loss Boost Your Mood Instantly: 10 Simple Ways to Feel Better When You’re Down 5 Effective Yoga Poses With Hyperbolic Diet Plan What Is Acupressure Points With Pros And Cons Nude Fitness and Its Benefits Can You Eat Cold Chicken Best 7 Positive Health Effects or Benefits of Surya Namaskar Hakini Mudra: Benefits, Side Effects, How To Do and Precautions 6 Major Keys to Burn Fat And Gain Muscle At The Same Time Understanding CrossFit Soreness: A Comprehensive Guide
Appointment
Ask Question
Talk2Expert
Q&A
Health Tracker
Workout
Nutritious
Meditation
Well-Being
Mood Music
Social Service
Podcast E-book
✓ Evidence Based
193
Reads
66

4 Foods That Are Not Good to Reheat in the Microwave

Medically reviewed
Our Review Process
Our content undergoes a rigorous editorial process, including fact-checking and clinical review by qualified medical experts.
READ MORE →

Our Editorial Team
Lisa Valente (Nutritionist), M.S., RD
AUTHOR
Laine Greenawalt
MEDICAL ADVISOR
by   Laine Greenawalt
Laine Greenawalt ✔ Verified Expert
Laine Greenawalt is a Registered Dietitian passionate about assisting athletes of all ages, shapes, and sizes attain their most attainable via ideal nutrition. She has…
READ MORE →
—Written by   Lisa Valente (Nutritionist), M.S., RD
Lisa Valente (Nutritionist), M.S., RD
Lisa Valente is an enlisted dietitian and nourishment supervisor. She learned at the College of Vermont, where she finished her undergrad concentrates on in sustenance, food science and dietetics. Know More. Learn about our editorial process.
READ MORE →
Updated on April 29, 2026
Why This Was Updated
We continuously monitor the health landscape and update our articles to reflect the latest evidence.

Updated on April 29, 2026

VIEW ALL HISTORY →
—Published on April 29, 2026
Our editorial process ensures that the information we provide is well-researched and reliable. Learn about our commitment to quality in our editorial policy.
Listen to this article

The Fast Facts

  • While the microwave is a convenient and quick way to reheat many foods, there are certain types of food that are not recommended to be reheated in this manner.
  • You should only heat the spinach a second time if you have previously cooled the leftovers as quickly as possible, since the cold slows down the formation of nitrites.
  • Do not heat the rice or potatoes in the microwave, but in a saucepan.
FreakToFit logo

While the microwave is a convenient and quick way to reheat many foods, there are certain types of food that are not recommended to be reheated in this manner. Foods that are not good to reheat in the microwave include fried foods, as they tend to become soggy and lose their crispy texture. Similarly, breaded items like chicken nuggets or fish sticks can become mushy when reheated in the microwave.

Dairy products such as milk or cream-based soups can curdle and separate when microwaved, resulting in an unappetizing texture. Additionally, delicate foods like seafood or eggs can become rubbery and overcooked in the microwave. To maintain their taste and texture, it is best to reheat these foods using alternative methods such as oven, stovetop, or toaster oven.(1)

4 Foods That Are Not Good to Reheat in the Microwave.

1 Spinach.

Top 20 Iron Rich Foods For Your Kids
  • Spinach should not be reheated a second time. This is an old kitchen rule that is only partially valid today. The problem with spinach is that the plant naturally contains a lot of nitrate .
  • At room temperature, nitrate can be converted to nitrite , which is potentially carcinogenic. Together with certain protein breakdown products, nitrite can form carcinogenic nitrosamines.
  • High levels of nitrite can also cause: nausea, diarrhea and vomiting. 
  • You should only heat the spinach a second time if you have previously cooled the leftovers as quickly as possible, since the cold slows down the formation of nitrites.
  • Even if you refrigerate the food, you should not wait more than two days, because nitrite also forms in the refrigerator, although more slowly.
  • Heat the spinach in the pot over 70ºC for at least two minutes. In the microwave, food is often not heated evenly.

2 Mushroom.

14 Zinc Rich Food Which Boost Your Immunization Power
  • Champignons and other mushrooms are similar to spinach: if you store cooked mushrooms at room temperature for a long time, reheating can become critical.
  • With their high water, fiber and protein content, mushrooms are the ideal breeding ground for microorganisms and dangerous toxins can form during storage, which can cause nausea, vomiting and diarrhea.

Basic rules for reheating mushrooms:

  1. Cool mushroom dishes quickly after preparing them
  2. Store mushrooms in the refrigerator for up to a day.
  3. Heat the mushroom dish well to at least 70ºC. Therefore, pots or pans are more suitable than the microwave.
  4. Never reheat mushroom dishes that have already been reheated once.

3 Eggs.

What Is Metabolism And How It Works?

As with poultry, the protein structure can change, which can cause stomach upset. If the egg was stored at room temperature, salmonella can also multiply in it.

Therefore, it is best to eat only freshly prepared eggs and all egg-containing foods should be heated evenly to at least 70°C when reheated.

4 Potatoes and Rice.

What is Cold Rice Syndrome?

If you put boiled potatoes or rice in the refrigerator , a few hours after preparation, spores or bacteria may form .

If food is heated for a short time at a temperature that is too low, the bacteria do not die. In the worst case, the result is food poisoning.

Basic rules:

  1. If you are not going to eat it immediately, cool the boiled potatoes and rice immediately after preparing them and put them in the refrigerator.
  2. Do not heat the rice or potatoes in the microwave, but in a saucepan
  3. Heat the food completely and evenly for several minutes (at least 70ºC)


A Casserole Safer Than The Microwave.

  • All of the foods mentioned carry some risk when reheated. If potatoes, mushrooms, etc. have been stored without refrigeration for several hours, you should not reheat them at all.
  • For greater safety, these foods should not be heated in the microwave, even if they are cold enough, but in a saucepan. Because even in the refrigerator, bacteria can multiply or form nitrates.
  • Boiling or thoroughly heating can kill bacteria. However, this is not the case with microwave heating, because the food is not heated evenly or for long enough.

Side Effects of Reheating Foods in Microwave.

Reheating foods in the microwave is a convenient way to enjoy leftover meals, but it’s important to be aware of potential side effects that can arise from this cooking method. Here are four side effects of reheating foods in the microwave:

1 Nutritional loss.

Microwaving can lead to a loss of essential nutrients in some foods. Heat-sensitive vitamins, such as vitamin C and B vitamins, are particularly prone to degradation when exposed to high temperatures. This means that reheated foods may have lower nutritional value compared to their freshly cooked counterparts.

2 Uneven heating.

Microwaves heat food unevenly, resulting in hotspots and cold spots within the same dish. This uneven distribution of heat can lead to inconsistent reheating, potentially leaving certain areas undercooked while others become overcooked. Consuming undercooked food can increase the risk of foodborne illnesses caused by harmful bacteria or parasites.

3 Formation of harmful compounds.

Reheating certain foods in the microwave can result in the formation of harmful compounds. For example, when protein-rich foods like meat, poultry, or eggs are reheated improperly, they can produce toxins such as heterocyclic amines and acrylamide, which have been linked to an increased risk of cancer. Additionally, reheating oils and fats can lead to the production of harmful free radicals, which can contribute to oxidative stress and inflammation in the body.

4 Potential for plastic leaching.

Microwaving food in plastic containers or using plastic wraps can pose health risks due to the potential leaching of harmful chemicals into the food. Some plastic materials contain substances like bisphenol A (BPA) or phthalates, which can migrate into the food when heated. These chemicals have been associated with various adverse health effects, including hormonal disruptions and potential links to certain cancers.

💡 Tips FreakToFit.com
To minimize these side effects, it is advisable to use microwave-safe glass or ceramic containers when reheating food. Additionally, covering the food with a microwave-safe lid or microwave-safe wax paper can help promote more even heating and reduce the risk of plastic-related issues. It is also recommended to reheat food in shorter intervals with frequent stirring to ensure even heating and avoid potential hotspots.

Other Safety Precautions for Reheating.

Although it’s important to avoid certain foods in the microwave, proper food storage and handling is equally vital to avoiding health problems. Keep leftovers cool (within 1-2 hours) and stored in airtight containers in the refrigerator. This reduces the risk of bacteria growth when the food has been left out for too long.(2)

Reheated food should be heated to an internal temperature of 70°C to ensure any bacteria are destroyed. Microwaves can heat food unevenly, so it’s recommended to stir or turn the food halfway through the reheating process to kill any cold spots. Using a microwave-safe lid can also help to promote even heating.

It’s advisable to only reheat food once, as reheating twice can lead to food poisoning and loss of nutrients. If you have any doubts about how long the food has been stored, it’s best to throw it away to prevent food poisoning.

Another key consideration is the container you use. For example, do not use plastic containers because they may leak chemicals into the food when reheated. This precaution can greatly minimise long term health impacts.(3)

study
The chart highlights the impact of microwave reheating on key food safety and nutritional factors, showing higher risks related to bacterial survival and uneven heating, with moderate effects on nutrient loss and food safety when proper reheating practices are followed (based on recent food safety and microwave heating studies).

Pro Tip for Better Food Quality.

For the best flavour and texture, consider cooking your food on the stove, in the oven or even a steamer. These cooking techniques can distribute heat more evenly and retain flavour, particularly when cooking rice, mushrooms and eggs.

Bottom Line.

In conclusion, it is important to be mindful of the types of foods that are not suitable for reheating in the microwave. These foods can pose health risks and may result in a loss of taste, texture, and nutritional value. Foods such as eggs, rice, pasta, and breast milk should be reheated using alternative methods to ensure their safety and quality. By following proper reheating guidelines and utilizing alternative heating methods, we can maintain the integrity and safety of our food, promoting healthier and more enjoyable eating experiences.

+3 Sources

FreakToFit has strict sourcing guidelines and relies on peer-reviewed studies, educational research institutes, and medical organizations. We avoid using tertiary references. You can learn more about how we ensure our content is accurate and up-to-date by reading our editorial policy.

  1. Cooking with Microwave Ovens; https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/cooking-microwave-ovens
  2. Effect of yoga therapy on anxiety and depressive symptoms and quality-of-life among caregivers of in-patients with neurological disorders at a tertiary care center in India: A randomized controlled trial; https://www.sciencedirect.com/science/article/abs/pii/S0924224425004741
  3. Recent advances in microwave inactivation of foodborne pathogens: Key factors, mechanisms, and future perspectives; https://pmc.ncbi.nlm.nih.gov/articles/PMC9607893/

Last reviewed on

How we reviewed this article:

ⓘ SOURCES 🕖 HISTORY

FreakToFit follows strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and reputable medical organizations. We only use high-quality, credible sources to ensure the accuracy and integrity of our content.

    Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available.

    Current Version
    Apr 29, 2026

    Written By: Lisa Valente (Nutritionist), M.S., RD

    Reviewed By: Laine Greenawalt

    Apr 29, 2026

    Written By: Lisa Valente (Nutritionist), M.S., RD

    Reviewed By: Laine Greenawalt

    The dietary recommendations provided here are based on research and expert review. Individual needs vary — please consult a registered dietitian or nutritionist before changing your diet. Know More

    Lisa Valente (Nutritionist), M.S., RD

    Author
    Lisa Valente is an enlisted dietitian and nourishment supervisor. She learned at the College of Vermont, where she finished her undergrad concentrates on in sustenance, food science and dietetics. Know More. Learn about our editorial process.

    Laine Greenawalt

    Dietitian
    Laine Greenawalt is a Registered Dietitian passionate about assisting athletes of all ages, shapes, and sizes attain their most attainable via ideal nutrition. She has…

    Leave a Comment