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Dangerous Side Effects of Eating Microwaved Meals, According to Science

Those convenience meals could be putting you at risk for weight gain, heart disease, and more.
FACT CHECKED BY Kiersten Hickman

Whether you're returning home late after a long day at the office or find yourself with precious little in the way of fresh ingredients in the fridge, grabbing a microwaveable meal often seems preferable to ordering another unhealthy—and expensive—takeout meal. However, while many microwave meals may bill themselves as healthy or diet-friendly, experts say they often do more harm than good. According to a 2015 study published in The British Journal of Nutrition, there were startlingly deleterious health effects recorded among adult study subjects who consumed prepared foods, including microwaved meals, on a daily basis.

The study's researchers found that the consumption of prepared meals, including "heat-and-eat" meals, was associated with not only poorer overall dietary quality—including increased consumption of fat and lower consumption of fiber—but a wide range of surprising health effects. Read on to discover the microwaved meal side effects you can't afford to miss. And if you want to improve your diet in a hurry, check out The 7 Healthiest Foods to Eat Right Now.

You may be at greater risk for certain cancers.

breast exam

The ingredient list on the back of that microwave meal may not tell the whole story when it comes to what you're actually consuming.

"Using electromagnetic radiation, the microwave causes food and the containers in which the foods are cooked to super-heat," says Spencer Kroll, MD, PhD, an internal medicine specialist with Kroll Medical Group. "This super-heating can cause breakdown of the chemical components of the containers surrounding your food and these dangerous chemicals can potentially leach into your food."

Kroll notes that among the most concerning of these chemicals is bisphenol A (BPA), the consumption of which has been linked to a variety of cancers. According to a 2015 review of research published in Medicine (Baltimore), BPA is linked to the development and spread of both breast and prostate cancer cells. And if you want to protect your health, check out these 22 Foods That May Affect Your Breast Cancer Risk.

Your blood pressure may rise.

checking blood pressure

Just because that microwave meal is low in calories doesn't mean it's good for you. In fact, the copious amounts of salt used to make many microwave dishes palatable could contribute to serious health problems down the line.

"Microwave ready meals are high in sodium and other preservatives," says Kroll. "High sodium foods accelerate blood pressure problems and can lead to heart disease."

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You might retain water.

woman doubled over in pain holding her bloated stomach suffering from gi gastrointestinal distress

It's not just your cardiovascular health that's at risk when you consume sodium-laden microwave meals. As registered dietitian nutritionist Shena Jaramillo, MS, RD, explains, microwaved meals "are high in sodium which can lead to water retention."

Over time, this may lead to other healthy habits, like drinking enough water, falling by the wayside. According to a 2017 study published in The Journal of Clinical Investigation, just a 6-gram increase in salt consumption—equivalent to approximately 1.2 teaspoons of salt—leads to water retention sufficient enough to both "[reduce] thirst and fluid intake." And for more incentive to steer clear of the frozen food aisle, check out the Dangerous Side Effects of Eating Frozen Foods, According to Experts.

You could put yourself at risk for food poisoning.

Woman suffering from stomach cramps in her bedroom at home

Though microwaving has been touted as a means of killing everything from viruses to bacteria, it may not actually mean you're in the clear when it comes to food poisoning. In fact, it's one of the microwaved meal side effects that could leave you sidelined in the short term.

"Microwaving food requires high temperatures and food temperatures are uneven," says physician Leann Poston, MD, of Invigor Medical, who cautions again microwaving meals more than once. "Some parts of a food portion may not reach a high enough temperature to kill bacteria."

You might see your waistline expand.

Doctor measuring obese man waist body fat.

If you're eating microwaved meals in an attempt to whittle your waistline, don't hold your breath.

According to the British Journal of Nutrition study, greater consumption of prepared foods, including microwaved meals, "was found to be independently associated with abdominal obesity."

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Sarah Crow
Sarah Crow is a senior editor at Eat This, Not That!, where she focuses on celebrity news and health coverage. Read more about Sarah