Beware Of These Metabolism-Slowing Foods And Drinks

Contrary to popular belief, you can change your metabolism. Proper diet, exercise, and sleep can speed up your metabolism. But certain foods slow it down. Even “healthy” foods, such as bread and unwashed fruits and vegetables, can make you gain weight. If you want to stimulate your metabolism, avoid these foods and drinks.

Why White Bread Causes Weight Gain

Homemade Hokkaido wheat toast bread is sliced on white cloth on table.
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Natasha Breen/REDA&CO/Universal Images Group via Getty Images

White bread is made of refined grains, which are stripped of fiber and nutrients and loaded with sugar. Because of this, these grains can worsen your metabolism. In 2014, a study in The American Journal of Nutrition found that refined grains are much worse for your metabolism than whole grains.

White bread is made from simple carbs, which are easy to break down. This can cause your metabolism to relax instead of vamping up. The good news is that switching to whole grains will boost your metabolism, says a 2017 study from the same journal.

Caffeine Is Good, But Too Much Coffee Is Bad

A person brews coffee.
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Bryan Thomas/Getty Images

Caffeine is a metabolism booster. However, coffee comes with a downside, especially if you drink too much. According to nutritionist Amy Shapiro, coffee is a natural appetite suppressant. Eating too little will slow your metabolism, not boost it.

Research in Obesity explains that eating too few carbs puts your body into survival mode. By the time you eat dinner, your body will convert calories into fat, fearing that it will be starved again. If you drink too much coffee and eat too little, your metabolism might lower by 23%, says the International Journal of Obesity.

You Should Wash These Fruits And Vegetables

A woman washes blueberries in the sink.
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Mohssen Assanimoghaddam/picture alliance via Getty Images

If you don’t wash fruits and vegetables before eating, you’ll want to start. In 2012, an animal study on fungicide found that it can lead to weight gain. Although this study was on mice, it might do the same in humans, at least in large quantities.

Registered dietitian Tanya Zuckerbrot says that the most pesticide-heavy produce is called “the Dirty Dozen.” These are water-heavy produce that soaks up fungicide easily, including apples, strawberries, celery, tomatoes, and more. Always wash these before eating, and if you’re worried, consider buying organic.

Why People Gain Weight From Too Much Salt

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Charles Deluvio/Unsplash

Eating too much sodium can overwork your metabolism and make you eat more. According to Mark Zeidel, a nephrology professor at Harvard Medical School, salt dehydrates the body. This forces the body to release more water, which requires more energy and makes people hungrier.

This cycle of over-eating can have negative effects on your metabolism and cause you to gain weight. That said, you should still eat salt. Research in the Journal of Clinical Investigation concluded that a moderate amount of salt helps people burn fat.

Even “Healthy” Juice Cleanses Ruin Metabolism

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While an occasional glass of juice won’t hurt you, don’t drink too much. Because of its high sugar content, juice can harm your metabolism. In 2012, a study by the American Public Health Association confirmed that drinking 100% fruit juice increases the risk of metabolic syndrome, especially in children.

Even “healthy” juices with no added sugars can slow your metabolism and make you gain weight. According to a 2016 study in Food Function, juicing diets actually destroy your metabolism by robbing the body of protein and nutrients. It does not “kickstart” or “detoxify” the body.

Eating Fast Food Meals Makes Your Digestive System Struggle

A McDonalds burger is seen through the window.
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Even a few fast-food meals can mess up your metabolism. In 2015, a study in the journal Obesity examined participants who ate fast food for five days. Despite eating the same amount of calories as before, their digestive system struggled, and their body did not convert sugar to energy as efficiently.

According to the Chicago Tribune, fast food has so much fat and sugar that it spikes insulin levels. When your blood sugar drops back down, you might feel tired and hungry again. This leads people to overeat, quickly becoming a vicious metabolic cycle.

Stop Eating Candy At Night

Various sweets and candies are arranged at a store.
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RDImages/Epics/Getty Images

Candy is one of the worst foods for your metabolism. In 2016, a study in Critical Reviews in Clinical Laboratory Sciences confirmed that sugar contributes to metabolic disease. Specifically, it disrupts “lipid and carbohydrate metabolism” to make the body gain fat.

Candy is especially bad when you eat it at night. According to UAMS Health, people tend to be sedentary at night, which slows down the metabolism. Combine that with excess sugar and (occasionally) over-snacking, and you have a recipe for weight gain. If you want dessert, limit your portion sizes.

Even Low-Calorie Frozen Meals Make People Gain Weight

A person pulls a Healthy Choice frozen dinner from a grocery store shelf.
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Some people might think that they’re eating healthy by choosing low-calorie frozen dinners. But these meals have a downside. According to registered dietitian Amy Gorin, they might harm your metabolism because they do not provide enough calories.

When meals are less than 300 calories, it is too low and might slow your metabolism. Even if you eat after the frozen meal, you might over-eat, which also harms metabolism. On top of that, pre-packaged foods are preserved with sodium, and consuming too much sodium can cause weight gain too.

Sugar Doesn’t Only Affect Blood Pressure

Two spoons hold white and brown sugar.
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Tom Kelley/Getty Images

Many people know that sugar harms the heart, but did you know that it also messes up your metabolism? Cardiologist Nasser Khan says that sugar’s influence on blood pressure, blood glucose, and coronary heart disease all contribute to metabolic syndrome.

Sugar does not give the metabolism more energy. Instead, too much sugar gets stored as fat. Over time, your body might interpret the excess sugar as starvation, and it will burn muscle instead. The less muscle you have, the less your metabolism works, explains WebMD.

Soda Makes More Fat And Inflammation

A person pours soda into a cup from a machine.
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Mario Tama/Getty Images

The more soda you drink, the worse your metabolism becomes. The University of Rochester Medical Center explains that sugar raises your insulin and fat levels. With more fat comes more inflammation, which interrupts the metabolic process.

In The American Journal of Clinical Nutrition, a 2017 study noted that soda slows down metabolism. When your metabolism does not break down fat swiftly or efficiently, you can gain weight faster. The American Heart Association recommends that you drink no more than three cans of soda per week.

Even Diet Soda Does Damage

A close-up shot shows cans of Diet Coke.
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Ramin Talaie/Corbis via Getty Images

Although diet soda is flavored with artificial sweeteners, it still harms your metabolism. In 2017, research in Current Biology found that drinking diet sodas raised a person’s risk of obesity and metabolic disease.

The reason has to do with its sweetness and low calories. Neuroscientist Dana Small told Vox that “[sweetness] regulates the metabolic signal.” When the body detects sugar, it works to break down calories. But with artificial sugar and no calories, the body does not activate the metabolism. This mainly happens when you drink a diet soda with carbs.

Instead Of Sea Salt, Eat Iodized Salt

A pile of sea salt is shaded on one side and illuminated on the other.
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Tim Graham/Getty Images

Should you eat sea salt or iodized salt? According to nutritionist Dana James, you should buy iodized salt. Sea salt does not contain iodine, which your body needs to regulate metabolism. Research in Physiological Reviews discovered that sufficient iodine intake can prevent metabolic syndrome.

That said, you do not need to get iodine from salt. Harvard Health Publishing claims that you can also get that nutrient from ocean-caught fish, milk, cheese, eggs, yogurt, and certain vegetables. Remember that too much salt can strain your metabolism too!

Too Much Red Meat Raises The Risk Of Metabolic Syndrome

Cured red meat is seen under greens and a spoon.
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An occasional serving of red meat is healthy, as it helps your body build proteins. However, too much can worsen your metabolism. In 2018, a review of several studies in Nutrients examined red meat and metabolic syndrome. People who eat high amounts of red meat have an increased risk of metabolic syndrome between 14% and 35%.

Over-consuming red meat also results in adverse health effects. Eating red meat every day triples the amount of a heart disease chemical called Trimethylamine N-oxide, according to a 2019 study. Opt for other protein sources instead.

Soy Protein Isolate Is Different From Soy

A person picks up squares of tofu.
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ADEK BERRY/AFP via Getty Images

Some people worry that eating “processed” soy will mess up their metabolism and make them gain weight. But registered dietitian Karen Ansel explains that they might be mixing up soy with soy protein isolate, a separated form of protein that appears in processed foods.

While there is no evidence that soy destabilizes metabolism, processed foods are linked to weight gain. Their large amounts of sugar, salt, and preservatives can slow your metabolism. “If you are constantly seeing the words ‘soy protein isolate’ on the ingredient lists of the foods you eat, it might be a wake-up call that you’re eating too many processed foods,” Ansel told Global News.

Processed Meats Are Worse Than Cured Meats

Hot dogs line grocery store refrigerator shelves.
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JIM WATSON/AFP via Getty Images

If you’re a meat-eater, your metabolism is more likely to suffer from processed meat. In July 2020, researchers compared ten processed and non-processed meats. Processed meats were worse on digestion, non-processed meats were not, while cured meats such as ham were in the middle.

During a 2019 study, participants ate the same amount of calories for non-processed and processed meats. While those who ate non-processed meats lost body fat, the other group gained it. Clearly, the fat and preservatives worsen the metabolic system in a noticeable way.

Artificial Sweeteners Are No Better

Packets of equal and splenda are offered at a coffee bar.
Richard Levine/Corbis via Getty Images
Richard Levine/Corbis via Getty Images

In February 2020, a study in the journal Nutrients found that even tasting something sweet can change your metabolic response. Sucrose, a common artificial sweetener, has negative effects. It changes how the body processes fat, which can lead to obesity.

According to the researchers, sucrose increased insulin sensitivity within one hour after eating. Even tasting the sweetener altered blood glucose and carbohydrate metabolism in participants. These are bad news for people who want their metabolisms to break down sugar swiftly and healthily. If you’re a fan of artificial sugar, choose a natural one like Stevia.

The Worst Cooking Oil: Soybean Oil

Containers of soybean oil line shelves in a Chinese supermarket.
Doug Kanter/Bloomberg via Getty Images
Doug Kanter/Bloomberg via Getty Images

Not all vegetable oils are healthy. In January 2020, research in Endocrinology found that soybean oil deteriorates metabolism. The oil prevents the brain from producing oxytocin, a hormone that regulates food intake and energy. The lack of this hormone slows down metabolism.

In simpler terms, soybean oil influences the brain to change the metabolic process. Other studies, such as 2015 research in PLoS ONE, found that soybean oil increases the risk of obesity and diabetes. This oil is most often used for frying fast food.

Certain Pesticides Can Impact Your Metabolism

Farmers spray crops with pesticides.
Abid Katib/Getty Images
Abid Katib/Getty Images

Some pesticides that are sprayed onto fruits and vegetables can harm your metabolism. For instance, a high amount of organochlorines can make it difficult for people to lose weight, according to a 2003 study in Obesity Review.

Why does this happen? Californians for Pesticide Reform explains that some chemicals mimic or block hormones. This results in slower digestion and metabolism. The good news is that many of these pesticides are getting banned, and you would have to consume a lot of them to experience these effects.

The Dark Side Of French Fries

A container of McDonald's French fries is tipped over.
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In 2018, a study in Cell Metabolism warned people not to eat French fries with diet soda. When artificial sweeteners and carbohydrates combine, they negatively impact the brain. The brain produces fewer metabolic hormones, which slows down your body’s digestion and nutrient absorption.

And it’s not just with diet soda. Senior author Dana Small explained that French fries have high carbohydrates, high fat, and low fiber. This combination slows down the metabolism, just as other processed foods tend to do. It seems that most fast food meals worsen metabolism overall.

Granola Is Not As Healthy As It Seems

Granola is offered in small sample cups with wooden spoons.
Brian Ach/Getty Images for New York Magazine
Brian Ach/Getty Images for New York Magazine

Although granola is often touted as a health food, it has some hidden dangers. One is sugar, according to registered dietitian Lisa Moskovitz. According to the Washington Post, granola products can have up to 14 grams of sugar, which can cause a blood glucose spike and disrupt your metabolism.

The other problems are granola’s high calories and processed sweeteners. Some are made with processed honey, which is no different from artificial sweeteners that stall the metabolic process. If you want to eat granola, you want to might consider making your own.

Heavy Drinking Releases Toxins Into The Body

Three wine glasses are empty.
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Too much drinking can harm the body, and a 2020 study asserted that this may be due to metabolism. To metabolize alcohol, the body releases chemicals that convert it into acetaldehyde. Acetaldehyde is a known toxin and carcinogen that can harm the liver.

Not only does drinking add toxins into the body, but it also impairs digestion and inhibits nutrient absorption. This is why excessive drinking can slow your metabolism. According to research in Current Obesity Reports, light to moderate drinking will likely not contribute to weight gain, but heavy drinking will.

White Rice Is Not The Perfect Side Dish

White rice is served with teriyaki chicken and tempura.
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While brown rice can improve your metabolism, white rice does not. In 2013, research in BMC Public Health concluded that eating white rice raises the risk of metabolic syndrome. Meanwhile, eating whole grain rice lowers that risk.

Like white bread, white rice is made from refined grains, which transform into sugar in the body. According to a 2014 Iranian study, adults who regularly ate white rice for three years had a higher risk of metabolic syndrome than those who did not. You can have it once in a while, but not all the time.

Beware Of Seeds With Omega-6 Fatty Acids

Pumpkins seeds lie in a pile.
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Patrick Pleul/picture alliance via Getty Images

What do sunflower seeds, pumpkin seeds, and sunflower oil have in common? They all contain omega-6 fatty acids. According to the scientific journal Nutrients, omega-6 fatty acids have a different effect on fat tissue and inflammation than omega-3s. In other words, omega-6s are worse for your metabolism.

During a 2016 study, researchers discovered that having a higher ratio of omega-6s to omega-3s can cause weight gain. That is not to say that omega-6s are unhealthy; they can lower your risk of heart disease. But if you are focusing on metabolism, do not eat too many seeds or seed oil.

In Terms Of Metabolism, Butter Is Better Than Margarine

Sticks of Margarine are piled on top of each other.
Scott Olson/Getty Images
Scott Olson/Getty Images

While butter can improve metabolism with its healthy fats, margarine is the opposite. In 2010, a study in The European Journal of Clinical Nutrition noted that the trans fats in margarine worsen metabolism. Non-trans fat margarine did not have that effect.

According to the researchers, trans fats trigger insulin resistance and also inhibit nutrients from being processed by the liver. All of this interrupts digestion and metabolism. During an animal study, rats had better metabolic rates after eating saturated fats (as in butter) than trans fats.