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The Worst Foods & Drinks for Your Metabolism

Sure, you read about the foods that speed up metabolism but what about the foods that slow it down?

There's no doubt about it: figuring out how to lose belly fat is hard. If you're hitting the gym, eating right, and getting those Zzz's what else could you possibly do to reach those weight-loss goals? One answer: ditch these foods that slow down your metabolism.

Metabolism, a naturally-occurring biochemical process whereby your body converts food and drinks into energy, is a key factor when it comes to achieving that number on the scale. The more efficient your body is at burning calories and transforming them into energy, the less likely you'll put on extra pounds in the first place.

But when this natural ability isn't working in its most effective state, your body isn't able to shred as much fat as you'd like. And one of the reasons why this slowdown happens is because you're consuming these metabolism-wrecking foods. With each bite of these choices, you move the weight-loss finish line that much farther away. Check out which surprising foods are slowing your metabolism, and instead, stock up on The 7 Healthiest Foods to Eat Right Now.

Refined Grains

straining pasta in sink

It's no secret that pasta, bread, and pizzas shouldn't be on your list of go-tos when you're trying to keep that belly flat. But when you do want to treat yourself, do it the right way. Large quantities of gluten, starch, and phytic acid may hurt your metabolism. In fact, when comparing the human body's ability to digest grains, researchers agreed that choosing refined grains was a lot more damaging to our insides. The American Journal of Clinical Nutrition published a study that explained that when choosing whole grains instead of refined ones, your body will have an increased calorie loss because there are fewer calories saved during digestion and your metabolism becomes more active. The more simple a carb is (think: white bread, white pasta, and white rice) the easier it is for your body to break it down. This means your metabolism doesn't have to work as hard to break these foods down. When you eat more refined grains, your metabolism revs up as your body works harder to break these nutrients down. Plus, these simple carbs end up spiking your blood sugar leading to extra fat storage.


Alcohol wine glasses
Kelsey Chance/Unsplash

Sure, a nice cup of vino may be great to end the day. But drinking too much alcohol in one sitting, which is more than one drink per day for women and two for men, can take a major toll on your metabolic rate. It may surprise you, the reason alcohol is linked to weight gain is not just about the calories. According to research, drinking alcohol decreases the body's fat-burning ability by 73%. When drinking at an excessive rate, acetaldehyde is formed. This highly toxic substance waves many internal red flags to your body's digestive system. Instead of your metabolism burning the calories you consume, your body has to work to detoxify these chemicals.

Conventional Produce

Fresh produce in grocery store

Eating food contaminated with pesticides can lead to a slower metabolism — and the more of these foods you have in your diet, the worse off you are. A study in Obesity Review discovered that people whose bodies show high levels of organochlorines, a type of pesticide, tend to have a slower metabolism and have a more difficult time losing weight. Another study in Spain found that those with the highest concentrations of these pesticides were born at a low birth rate than those without the chemical in their bloodstream.

Traditional Yogurt


Greek yogurt offers many metabolism-boosting benefits thanks to its high protein concentration and probiotics. But when you venture into the world of traditional yogurt, you're not dishing yourself a dairy product that's well worth it. These alternatives have little to no protein when compared to Greek yogurt, and "If you aren't consuming enough protein to keep your muscles and cells healthy, the body ends up breaking down muscle to access the nutrients it needs—and this spells trouble. Less muscle mass means a slower metabolism, which over time, can cause weight gain," explains Alissa Rumsey, RD and former spokesperson for the Academy of Nutrition and Dietetics.

Plus, be wary of yogurts with too much added sugar and fruit puree. These simple carbs are quickly digested, causing a spike in blood sugar and an inevitable crash, leaving you feeling hungry and craving more simple carbs. Stick to plain 2% Greek yogurt or a low-sugar, high-protein Icelandic yogurt such as Siggi's.

Fruit Juice

bottled juices

Drinks like fruit juice put a major damper on your diet. Just one glass of the classic no-pulp OJ in the morning serves you a whopping 22 grams of sugar, and a bowl of sweetened cereal can set you back more than 20 grams of sugar per bowl. When you consume such high quantities of the sweet stuff, your levels of blood glucose soar into the stratosphere. This tells your metabolism to slow down, meaning you'll burn fewer calories and add to your fat stores.



You probably know soda isn't doing your body any favors, but did you know it could actually be slowing down your metabolism? Many sodas are sweetened with high fructose corn syrup: a sweetener that contains high levels of a sugar called fructose. Your metabolism is your body's ability to turn food into energy. Because fructose isn't metabolized into direct energy like glucose is, consuming high levels of this sweetener can slow down your metabolism. In fact, a 2010 review published in the journal Current Hypertension Reports, found a connection between high fructose corn syrup-sweetened beverages and metabolic disorders.

Restaurant Fried Food

Burger and fries

Fried foods from restaurants might be your guilty pleasure, but you should be aware of the repercussions of eating the stuff. These fatty foods can be fried in partially hydrogenated oils, or trans fats, which can gum up your metabolism until it's hit a virtual standstill. In fact, researchers at Wake Forest University found that animals given a diet high in trans fats gained more weight than those consuming a diet full of monounsaturated fat, even with no difference in total caloric intake. Plus, research published in the American Journal of Clinical Nutrition has positively linked the consumption of fried foods with an increased risk of abdominal obesity and weight gain in adults, putting your health at risk with every bite.

Farmed Beef

ground beef

Indulging in a burger from time to time may not seem like a big deal, but if you're eating farmed beef, you could be setting yourself up for a serious metabolic slowdown. Non-organically farmed cattle are often treated with antibiotics, which can have a profoundly damaging effect on our gut bacteria. Researchers at Harvard found that long-term consumption of diets high in animal proteins can also irreparably alter the balance of bacteria in the gut, slowing your metabolism along the way.

Frozen Meals

frozen meal

What those frozen dinners lack in calories and fat, they more than make up for in metabolism-slowing ingredients. To make up for their lack of flavor, many frozen meals load their recipes with sugar, sodium, and trans fat in the form of hydrogenated oils.

Regular Sea Salt

Sea salt

Opt for iodized salt instead. Iodized salt has a positive effect on your thyroid and, in turn, your metabolism. "Without sufficient levels of iodine, your thyroid function becomes impaired and it's harder for your body to burn fat," says Dana James, MS, CNS, CDN, who suggests sneaking sea vegetables into your diet at least three times a week.

Granola Bars

chocolate granola bars

Often thought of as a health food, granola and granola bars are one of the sneakiest causes of metabolic meltdowns out there. While their oat base can help lower your blood pressure and cholesterol, the shocking amount of sugar, high fructose corn syrup, and preservatives in most recipes can make even the most efficient metabolisms slow to a snail's pace. Think your preferred brand is exempt from those unhealthy ingredients? A look at the nutrition labels says otherwise! If you're looking for a healthier snack bar, check out our list of the best healthy, low-sugar protein bars.