What's the Difference Between Protein Shakes, Meal Replacement Shakes, and Meal Shakes?

protein shakes, meal replacement shakes, meal shakes

So you finally got comfortable with your friends chugging down protein shakes before and after their workout, and now their new thing is meal shakes?! 

What the hell is a meal shake anyway? And how is it different from a protein shake?


Excellent questions! Let’s take a look.

What is a Protein Shake?

what is a protein shake

Protein shakes are drinks made by mixing a few spoonfuls of protein powder with either water or milk. 

Generally, protein powder is made from whey protein - one of the primary proteins found in dairy products (though nowadays, many other types of protein powders are available). 

Whey is considered a complete protein source because it contains all 9 essential amino acids. Your body needs those amino acids to break down food, repair body tissue, and perform many other bodily functions.

Protein shakes are a quick, easy, and pretty affordable way to increase your protein intake if you, for example, want to support your muscle growth.

The typical amount of protein in a prepared protein shake or ready-to-mix protein powder is between 25-30 g of protein per serving. This amount is more than half of the total protein the average person is advised to consume per day (i.e., 0.8 g of protein per kilogram of body weight) [5].

What is a Meal Replacement Shake?

what is a meal replacement shake

Meal replacement shake and meal shakes tend to get mixed up, but watch out!  Because the two are very different…

‌A meal replacement shake is a liquid meal designed to replace breakfast, lunch, or even dinner - generally with fewer calories than a ‘normal’ meal. That’s why meal replacement shakes are basically always used for losing weight [1]. 

They’re similar to a protein shake, in that, generally, they’re also a powdered mix of nutrients which you mix with water to consume as a shake.  

Meal replacement shakes also tend to be high in protein. Protein helps you feel full for longer without adding too many calories. It’s an easy way to support weight loss without losing muscle mass

What is a Meal Shake?

what is a meal shake?


meal shake is a drinkable meal that provides all the nutrients of a nutritionally complete meal. 

There are two essential ways in which a meal shake is different from a protein shake or meal replacement shake:


  • Purpose
  • Nutrition 

That’s because meal shakes are designed to be nutritionally complete meals.  

Nutritionally complete meals contain all the recommended nutrients your body needs in the ideal amounts for optimal health. These ideal amounts are based on the average adult person and have been established by leading health organisations like the World Health Organization and the European Food Safety Authority. 

Sounds pretty darn amazing, right?! 

But stay sharp: some meal replacement shakes may look like meal shakes and vice versa! So be sure you take a look at the label of a shake before you the wrong type of meal. 

A nutritionally complete meal replacement shake should look a bit like this [1]:


  • 45-60 g Carbohydrates
  • 14-25 g Fat
  • 20-30 g Protein
  • 7-10 g Fiber


Carbs and fat are essential, but a meal replacement shake typically will have a relatively high amount of protein and fibre and low amounts of carbs or fats. More protein and fibre help you to feel fuller longer and reduce the total number of calories in the meal [2]. 

So What is the Difference? 

The most significant difference between protein shakesmeal replacement shakes, and meal shakes is that meal shakes are designed to be nutritionally complete meals. 

Meal replacement shakes and protein shakes, on the other hand, are far from nutritionally complete and are used simply to increase your protein intake and/or to lose weight. 

Protein Shakes: Pros and Cons 

Pro: they are convenient 


Consuming a pre-made or ready-to-mix protein shake is an easy way to get a quick protein boost. 


Pro: provides the most benefit for those 50-years and older


As we get older, our muscle mass diminishes. So consuming adequate amounts of protein daily becomes more and more critical. When you hit about 50, protein shakes can help you keep some lean muscle [8].

Con: they are not nutritionally complete


Unlike meal shakes, protein shakes are not nutritionally complete because they basically only add extra protein to your daily diet. So don’t use protein shakes to replace a meal - it’s just a supplement. 


Con: many contain common allergens


Protein shakes often contain common food-based allergens such as milk, egg, and soy. Finding an allergen-free variety can be difficult.


Con: protein shakes can be expensive


Protein shakes can get pretty expensive. There are affordable options available, but these often have less protein per serving and/or contain poor-quality ingredients that could harm your overall health.

Protein shakes are used to build or maintain muscle mass, so they’re typically used by professional athletes, bodybuilders, and self-proclaimed gym rats. 


But there are other reasons why you might want to use protein shakes [6]:


  • Needing to maintain your muscle mass as you age
  • Having difficulties meeting your daily protein needs through diet alone
  • Having problems absorbing protein in your intestinal tract (*diagnosis provided by a physician)


Interestingly enough, many studies have found that consuming more protein than your daily recommendations provides only limited muscle growth benefits. Especially when you’re already consuming enough protein per day through your food [7]. 

Meal Replacement Shakes: Pros and Cons


Pro: easy to prepare


Preparing a shake requires very little time or effort. Buying ready-to-drink meal replacement shakes is even easier. 

Pro: can help you lose weight 

Because of the relatively high amounts of protein and fibre, a meal replacement shake will keep you feeling full for quite some time, even though it lacks nutritional value. If you’re trying to keep your caloric intake down, this might be a good option for you. 


Con: may be too low in calories


If your shake has too few calories per serving and you're consuming them regularly it may have a counteractive effect on weight loss [3]. This is because continuous limitation of calories under your daily energy needs causes stress on the body and triggers natural responses that, such as excessive steroid hormone release that stimulates weight gain while also increasing fatigue, muscle weakness, bouts of illness, etc. [3].

Con: may not contain enough nutrition

Carbs and fats are an essential part of a healthy diet, but because they bring a lot of calories to the table (pun intended), they are often barely found in meal replacement shakes. This way, the amount of calories stays low. 

Meal Shakes: Pros and Cons

Pro: easy to prepare


ready-to-mix shake powder requires little preparation, while pre-made replacement shakes are a quick ready-to-go meal. If you have difficulties finding time to prepare and consume food, these shakes are a great way to keep you fed and on the top of your game.


Pro: nutritionally complete


Nutritionally complete meal shakes contain all the nutrients you need to be nutritionally complete while also giving you the option to limit calories [1].


Pro: high in fiber


The high fiber content in meal replacement shakes helps to keep you feel fuller for longer. More fiber also helps digestion and prevents uncomfortable post-meal bloating! [2].


Cons: you need to read labels carefully


The difference between meal shakes and meal replacement shakes is not always clear, so you need to pay close attention to the ingredient label to ensure the product is of high quality. Make sure to check for:


A proper ratio of major nutrients (i.e., carbs, fat, and protein)

At least 3 grams of fiber per serving

Limited added sugars (<10 grams per serving)

No artificial ingredients


A meal shake may be right for you if you:



Yes, meal replacement shakes are generally used for losing weight, but nutritionally complete meal shakes also help you lose weight. However, they can also help you gain weight!  


Protein Shake, Meal Replacement Shake, Meal Shake: Which is Right for You?


To determine if a meal replacement shake or protein shake is right for you, you must assess your individual nutritional needs. Also, your main purpose of using these shakes.


A protein shake is what you’re looking for if you:


  • Want to support your muscle growth
  • Need to maintain your muscle mass as you age
  • Have difficulties meeting your daily protein needs due to a low-protein diet or intestinal protein malabsorption disorder

A meal replacement shake is right for you if you:

  • Want to limit your calories to promote weight loss

A meal shake is right for you if you:



Can a protein shake replace a meal? 

Unlike most meal shakes, protein shakes are not nutritionally complete because they basically only add extra protein to your daily diet. So don’t us protein shakes to replace a meal - it’s just a supplement. 

Can you eat too much protein?


Yes, it is possible to overeat protein.


Like any other nutrient, regularly consuming excessive protein can cause strain on your body. Generally, consuming over 2 g protein per kg of body weight daily is considered excessive protein intake [9].


Symptoms of eating too much protein can include:


  • Unexplained weight gain
  • Stomach discomfort and nausea
  • Dehydration
  • Fatigue
  • Irritability


*In severe cases, long-term excess protein intake can cause kidney problems [8]. Be sure to visit your primary care physician if you believe you are experiencing symptoms of protein overconsumption.


How many protein shakes can you have per day?


To avoid excessive protein consumption, you’ll want to limit yourself to 1 or 2 protein shakes per day. Of course, this depends on your specific daily protein needs.


Should you prioritize protein shakes or high-protein foods?


According to nutrition experts, you should prioritize consuming high-protein foods over protein shakes in your daily diet.


Protein shakes are a supplement and not meant to replace foods in your diet. Also, if you consume enough high-protein foods in your daily diet to meet your protein needs, you likely don't need a protein supplement at all. Even if you’re an athlete or weight lifter [7].


High-protein foods you can prioritize in your diet can include:


  • Lean red meats
  • Poultry
  • Seafood and shellfish
  • Low-fat dairy products
  • Eggs
  • Legumes (i.e., soy, beans, lentils, etc.)
  • High-protein grains and vegetables (i.e., quinoa, hempseed, chia seed, spirulina, etc.)


Aim for 20-30 grams of protein at every meal and 10-15 grams per snack [9].


Can you have a meal (replacement) shake at every meal?


No, you should not be consuming meal replacement shakes at every meal because it can contribute to a monotonous diet. A monotonous diet is the act of eating the same foods every day at every meal and snack. 

While there are benefits to a monotonous diet, such as easy meal preparation and calorie counting, there are also numerous drawbacks. Negative consequences of repetitively consuming the same foods like meal replacement shakes at every meal include boredom, difficulty losing weight, nutrient deficiencies, and can even increase risk of metabolic disease [4].

Instead, a diverse diet that provides a variety of essential vitamins and minerals as well as other unique and beneficial nutrients like antioxidants and plant-based phytonutrients keeps you in good health by protecting and maintaining all of your vital body functions [1].

A diverse diet contains a variety of nutrient-dense foods, but can also include 1 or 2 high-quality meal replacement shakes per day.


Do all meal (replacement) shakes provide the same nutrition?


No, all brands of meal replacement shakes are different as they all have their own unique nutritional formulation.


It’s important to know what you’re looking for in a meal replacement shake before purchasing one. Standard formulations you can choose from are:


Low calorie (for weight loss)

High calorie (for weight gain)

High protein


Diet type (i.e., plant-based, vegan, etc.)

Allergen or sensitivity-free (i.e., dairy-free, lactose-free, etc.)


Is it okay to have a meal (replacement) shake as a snack?



It is acceptable to have a meal replacement shake as a snack if you haven't consumed enough calories in your day. A shake as a snack may also help if you’re using a meal replacement shake to gain weight.


However, it is also essential to alter or combine meal replacement shakes with other foods as a snack to increase the nutritional diversity of your diet.


Allison Lansman, RDN, LD



1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851659/

2 https://pubmed.ncbi.nlm.nih.gov/26394262/

3 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6327254/

4 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6064642/ 

5 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6521232/

6 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4848496/

7 https://pubmed.ncbi.nlm.nih.gov/28937838/

8 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8068133/

9 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4045293/

Davis, L.M., Coleman, C., Kiel, J., Rampolla, J., Hutchisen, T., Ford, L., Andersen, W.S. and Hanlon-Mitola, A. (2010). Efficacy of a meal replacement diet plan compared to a food-based diet plan after a period of weight loss and weight maintenance: a randomized controlled trial. Nutrition Journal, [online] 9(1). Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851659/ [Accessed 31 Mar. 2022].


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