CNET logo Why You Can Trust CNET

Our wellness advice is expert-vetted. Our top picks are based on our editors’ independent research, analysis, and hands-on testing. If you buy through our links, we may get a commission. Reviews ethics statement

Meal replacement shakes: Can they help you lose weight, and who should use them?

Liquid meal replacements are no quick fix to shed pounds.

Caroline Roberts Digital Editorial Intern
Caroline Roberts writes articles and notifications for CNET. She studies English at Cal Poly, and loves philosophy, Karl the Fog and a strong cup of black coffee.
Caroline Roberts
4 min read

Meal replacement shakes, bars and powders claim to give you all the nutrition you need -- but is this really true?


If advertisements are to be trusted, liquid meal replacements are the answer to your weight loss woes -- they're cheap and satiating, and you don't even have to spend time cooking a healthy meal.

However, the reality isn't that simple. While liquid meal replacements can be a helpful tool when you're particularly busy or want to quell a sweet tooth, they won't magically help you lose weight. If you're curious about when exactly you should consider using meal replacement nutrition and how to do so safely, keep reading -- with the help of Registered Dietician Monica Auslander Moreno, we have all your questions answered.

What are meal replacement shakes?

Meal replacement products have been around for the past 50 years, and they're defined as any food that's consumed as a substitution for a meal or part of a meal. Meal replacements come in all different forms -- you're probably familiar with protein shakes like Ensure, but you can also find meal replacement bars and powders on the shelves of your supermarket.

Liquid meal replacements are typically around 150 to 200 calories, and often are high in protein. While we may think of them primarily as a weight loss tool, Moreno tells me that they're useful for people who can't meet their nutritional needs from foods alone. For example, high-level athletes, people with satiety issues who feel too full to eat enough and elderly folks can often benefit from drinking some extra nutrition.

The 17 best health and fitness apps for Apple Watch

See all photos

Will meal replacement shakes help me lose weight?

Losing weight is as simple as having your calorie intake be smaller than your calorie output -- but that doesn't mean it's easy. If you're too busy to cook healthy meals or have an uncontrollable sweet tooth, it's hard to use sheer discipline to force yourself onto a strict diet.


Orgain claims to provide a full meal in every serving.

The Vitamin Shoppe

Let's break down a typical meal replacement shake as it compares to a full meal. Orgain's meal replacement powder is made from plant-based ingredients and claims to provide "a delicious, organic meal in every serving." Each serving has 230 calories, with five grams of fat, 25 grams carbohydrates and 20 grams of protein. It only has a single gram of added sugar, but it's a bit high in sodium with 300 miligrams. A serving is chock full of vitamins, giving you nearly half your daily requirements of Vitamin C, Thiamin, Riboflavin and others.

On the other hand, let's analyze a simple meal consisting of 6 ounces chicken, a quarter cup brown rice and spinach with oil and vinegar dressing. It has 560 calories, with 20 grams of fat, 37 grams of carbohydrates, 53 grams of protein and some iron, calcium and potassium. As you can see, the meal replacement has way fewer calories, and pretty comparable micronutrient numbers.

Moreno says that meal replacements can be helpful for people with hectic lives. "The extended shelf life of these products is very useful for those on the go, who travel, who have long commutes, or who work late hours and need portable sustenance."

Moreno also says that meal replacements can also fill the craving for a nighttime sugar fix, especially since many of them taste sweet. Plus, some people feel more full after drinking a shake than they do after eating -- if this is the case for you, liquid meal replacements might be something to try once in a while.

Use These 27 Tips to Help You Sleep Better Starting Tonight

See all photos

As you can tell, whether or not meal replacement shakes will help you lose weight is a fairly personal question, and it all depends on your dietary habits and taste preferences.

It's hard to ascertain the answer to this question from a data perspective because most of the research proving the usefulness of meal replacement shakes are sponsored by those companies. But preliminary research has suggested that people with diabetes who use meal replacement products are more likely to lose weight.

When should I drink meal replacement shakes?

Before you start using meal replacement shakes, make sure they won't be incompatible with any of your health conditions. For example, Moreno tells me that pregnant and nursing people should avoid relying on them. But even if you've determined that meal replacement shakes fit your lifestyle, that still doesn't mean you should start using them for all of your nutrition.


Silicon Valley techies use Soylent to hack their diet, eliminating the need for eating.


Sure, some products like Soylent purport to give you all the nutrition you need. And plenty of people do month- or year-long experiments of surviving solely on the drink. 

But Soylent doesn't have phytochemicals, plant compounds that boost immunity, lower inflammation and more. Plus, Moreno points out that a diet of just meal replacement products can indicate an emotionally unhealthy relationship with food. Food isn't just fuel -- it's meant to be enjoyed.

Though it might sound counterintuitive, Moreno says meal replacement shakes shouldn't actually replace your meals. She says that to cover all of your macro and micro nutrient needs, you should eat food along with some of these products. For example, pair a liquid meal replacement with some dairy, fruits and vegetables to ensure you're getting adequate nutrition.

A meal replacement shake or bar can be perfect for a quick snack or breakfast while you're on the go. When incorporated as just one part of a balanced diet and exercise regime, they can certainly help you reach your health goals.

If you find that your diet consists almost entirely of meal replacement shakes, especially if it's because you're relying on knowing exactly what the nutrient breakdown is, this is a sign that you're entering into disordered eating patterns. Just remember -- meal replacement shakes and bars are just one tool in your healthy eating toolbox.

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.