Surprising Side Effects of Drinking Meal Replacement Shakes, Say Dietitians

If you’re the type of person who doesn’t have time to eat a healthy breakfast, you probably love shakes as meal replacements. Too busy at work to take a break for lunch? Make a liquid lunch out of this. Meal replacement is really handy. They are quick and easy to do. Hell, you don’t even have to get a blender dirty when you buy the bottled variety. They are a simple diet. No chewing required.

If you are trying to lose weight, they can make sense too. Many shakes contain fewer calories than the solid meals they replace. If you are concerned that you are not getting all of the nutrients you should be, then you can make sure you are getting the essentials that your normal diet may not provide.

With so many benefits, what’s not to love about meal replacement shakes? The possible negative side effects, that’s what. Read on, and for more on how to eat healthily, don’t miss out on 15 Underrated Weight Loss Tips That Actually Work.


Liquid meal replacements are certainly healthier than ordering fried chicken wings, but they’re not necessarily healthier than a healthy solid meal to replace. “I wouldn’t be a nutritionist if I didn’t point out that all of the nutrients you need, both macronutrients and micronutrients, can be obtained from solid foods,” she says Brittany Lübeck, RD, a registered dietitian and consultant for Oh So Spotless.

“Meal replacements should be used to fill in any nutrient gaps in your diet that you are aware of,” she says.

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“Many liquid protein and meal replacement shakes are lacking in adequate amounts of fiber, which is important for intestinal health, digestion, and heart health,” says Diana Gariglio-Clelland, RD, Nutritionist at “If your shake doesn’t contain fiber, it is probably missing.” Additionally, other beneficial nutrients such as antioxidants that you would get from eating whole foods may be lacking.

CONNECTED: 5 main side effects of not getting enough fiber, science says

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Another surprising side effect of meal replacements related to the above is weight gain. “Since many are too low in calories, you may still feel hungry after drinking and end up eating a higher calorie meal,” says nutritionist Ana Reisdorf, MS, RD, a registered dietitian for Wellness Edge. “I would recommend none that are less than 300 to 400 calories each. Meal replacement shakes are not a long-term solution to weight loss.”


Plant-based foods such as fruits and vegetables contain phytochemicals, which are compounds that give the product its color and offer a range of health benefits. “Meal replacement shakes are fortified with vitamins and minerals to meet nutritional needs, but they don’t offer the same benefits as eating a variety of whole fruits and vegetables,” says Gariglio-Clelland. Some meal replacement products take this fact into account and pump up the additives. “I like Invigor8’s SuperFood Whey Protein Shake because it contains green vegetables, essential fatty acids, adaptogens, probiotics and digestive enzymes,” says nutritionist Reisdorf.

CONTINUE READING: Surprising side effects of too few vegetables, says science

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Note that there is no safety testing or strict approval process from the Food and Drug Administration for dietary supplements like there is for pharmaceuticals. And with dietary supplements, there is no need to list potential side effects on the packaging. As a result, there may be a negative reaction to the chemical preservatives (sodium benzoate), thickeners (carrageenan, an inflammatory ingredient) or stabilizers (xanthan gum) contained in them.

“As a nutritionist, I encourage people to choose a protein powder or meal replacement that has been third-party tested and does not contain any unsafe ingredients or contaminants,” says Mary Wirtz, MS, RDN, CSSD, Nutritionist at Mom Loves Best. “To see if the protein powder you’re taking has been tested by third parties, visit NSF International,” she suggests.

Meal replacement shakes can still be useful for weight loss or a quick and convenient meal, but if you’re feeling a little shaky now and want to focus on whole foods again, try these foods that reduce and slow inflammation.

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