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Smoothie Habits That Are Shortening Your Life, According to Science

Smoothies can be incredibly healthy for you! Just don't fall for these mistakes.
FACT CHECKED BY Kiersten Hickman

If you're trying to be healthier this year, you're likely to look into switching to smoothies, and it's easy to see why. The nutrient-packed drinks are typically loaded with fresh or frozen fruits and veggies. Look at any TV show or movie where the protagonist suddenly makes a healthy switch and they're typically transitioning to consuming a smoothie instead of chowing down on pizza leftovers. Alas, like many other Hollywood myths, the idea of a smoothie as the one-stop-shop for health isn't all it's cracked up to be.

There are actually several ways in which smoothies can be considered unhealthy, and can ultimately shorten your life.

Megan Byrd, RD from The Oregon Dietitian, says that the best way to put together a smoothie is by combining fruits and veggies with a protein like Greek yogurt, protein powder, or nut butter in order to get the most from a smoothie and avoid some of the mistakes that we've highlighted below.

As for what not to do, we spoke with even more experts on the unhealthy smoothie habits that you should avoid, and their insights were eye-opening. Here's what they advise, and for more healthy tips, be sure to check out our list of The 7 Healthiest Foods to Eat Right Now.

Adding fruit juice.

juice into smoothie

It's important to make sure you have a sufficient amount of liquid in each smoothie so the whole thing doesn't end up as a big clump of pureed frozen fruit, but where people make unhealthy mistakes when putting together a smoothie is by choosing the wrong liquid to add in to it. Stephanie Mantilla, a plant-based nutritionist and the founder of Plant Prosperous, says one of the worst additions to smoothies is fruit juice.

"Where people get into trouble is when they start adding fruit juices to their smoothies," Mantilla says. "Fruit juice doesn't have the fiber that whole produce has. The fiber is what keeps you from getting a sugar rush. By drinking a lot of fruit juice, studies have shown that you have an increase in the risk of diabetes."

Here are 5 Reasons You Should Stop Drinking Juice, According to Dietitians.

Not adding enough protein.

making smoothie

A big focus of smoothies is having the right amount of fruit in them, and which fruits to include. But according to nutrition specialist Dr. Uma Naidoo, it's also important to remember to include a source of protein as well.

"The ideal smoothie to balance blood sugar levels, gently detox the body, aid the digestive system, build immunity, balance hormones, and give you sustained physical and mental energy has to include a combination of protein (which helps muscles), fiber (which feeds your gut bacteria), healthy fats (which are rich in antioxidants and anti-inflammatory properties) and folate found in leafy greens (which deliver loads of vitamins and antioxidants for optimal health)," Naidoo says.

She added that the combination "will ease inflammation and give you prolonged energy along with a feeling of satiety and satisfaction for hours."

Greek yogurt is a great way to get a protein boost. Here are The 20 Best and Worst Greek Yogurts, According to Nutritionists.

Adding too much sugar.


Smoothies are filled with fruit, which is a good thing. But like other good things in life, sometimes you can have a little bit too much of it. Fruits are loaded in natural sugars, so when people load up on fruits in their smoothies they can be consuming a large amount of sugar in just one serving of the drink.

"When you use mostly fruit in your smoothie, especially high sugar fruits like mango or pineapple, the sugar quickly adds up," says Jessica Meyers, a licensed physician assistant, and functional health consultant. "Blood sugar spikes, like from a fruit-heavy smoothie are linked to inflammation, obesity, diabetes, heart disease, hormonal problems, and more. Instead, opt for berries for a touch of sweetness with a much lower sugar content."

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Not including vegetables.

drinking smoothie

Smoothies are a good way to get servings of fruit in, but it's also important to include vegetables. As opposed to fruit, vegetables have much less natural sugar in them, according to Dr. Rand McClain, the chief medical officer of

"If by 'smoothie' we could change the parameters to include vegetables, [with] much less sugar, rather than fruits, then smoothies would be a healthier option," McClain says.

Here are the 14 Best Smoothie Ingredients for a Flat Belly.

Using low-quality protein powder.

making a smoothie with protein powder blueberries banana in blender

Anyone who is trying to bulk up knows that protein powder is a definite way to get results, and many use protein powders in place of regular meals. Smoothies are one way that meals can be replaced with a protein-filled drink, but it's important to make sure that the protein powder you're using is of good quality and contains nutrients.

"While this is common, most protein powders do not contain other vital nutrients required in a balanced meal," says Trista Best, MPH, RD, LD, a registered dietitian at Balance One Supplements. Anyone living with kidney disease should speak with their healthcare provider before adding protein powders to their diet.

Using smoothies as a meal replacement.

Woman pouring smoothie from blender into a glass

While it is common to use smoothies as a method of meal replacement, it's not encouraged. Naidoo says that eating a whole meal instead of a smoothie can lead to you feeling more full and satisfied after a meal.

"Due to the fiber content and more complex carbs in whole foods such as vegetables, digestion will take longer and the insulin will not spike, which will help prolong the feeling of satiety," Naidoo says.

Instead, choose for your smoothie to be a delicious snack to enjoy—especially if it's one of these 10 Fat-Burning Smoothie Recipes Nutritionists Always Drink!

Erin Yarnall
Erin Yarnall is a freelance reporter from the Chicago area. Read more about Erin
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