Low-Calorie Protein Powder

Low-calorie protein powder is a great way to get protein benefits without all the added calories or the need for cooking. 

Low-calorie protein powders come in many forms, including whey protein isolate, whey protein concentrate, and plant-based options, making it easy for everyone to find one that suits their needs. 

This blog post will discuss how to find low-calorie protein powder and review some of the best on the market today. 

We’ll also answer common questions about using these products and provide a conclusion summarizing our key points. 

So if you’re looking for an alternative way to get your daily dose of essential amino acids while keeping your caloric intake low, read on!

Overall winners

IsoPure Unflavored Whey Isolate Protein Powder

  • 100 calories
  • 25 grams
  • $1.56 – serving

Optimum Nutrition Gold Standard 100% Whey Protein

  • 126 calories
  • 24 grams
  • $1.06 – serving

Vega Sport Premium Plant-based Protein Powder

  • 170 calories
  • 30 grams – Plant based
  • $2.15 – serving

How to find low-calorie protein powders?

When you buy a low-calorie protein powder, you want the most protein (in grams) with the least calories. Seeing that there are four calories per gram of protein, 25 grams of protein will give you ~100 calories. (1)

That said, it is common for protein supplements to have trace amounts of fat (9 calories per gram) and 3-15 grams of carbohydrates (4 calories per gram). Both of which are going to contribute to the total calories.

Using this, 25 grams of protein is equal to about 100 calories rule of thumb. You can sift through all the protein powders and identify which ones are lower in calories and higher in protein.

Types of low-calorie protein powder

There is a range of low-calorie protein powders, notably whey protein concentrate, isolate, and plant-based proteins.

Whey protein concentrate is popular as it is the most bioavailable and contains the optimal ratio of essential amino acids. Its close relative is whey protein isolate, which has the same benefits but excludes residual lactose. (2

Plant-based proteins, such as pea, rice, and hemp protein, are available on the market. These sources typically have a limiting amino acid, meaning they offer an inferior protein quality compared to their whey counterparts. (3)

If you are wondering whether you should choose whey protein or a plant-based protein powder, check out this breakdown I did on Whey vs. Plant Protein.

Best low-calorie protein powders 

Without further ado, let’s get into the best low-calorie protein powders. Within this list, I broke down the top low-calorie protein powders into four categories, whey isolate, whey concentrate, plant-based, and others. 

Low-calorie whey protein isolates 

The first category is whey protein isolate. This is because regardless of the brand, the protein-to-calorie ratio will be the highest protein concentration with the lowest amount of calories. 

On average, whey protein isolate is 114 calories per serving and provides 27 grams of protein. This also means that 94.7% of the calories in whey isolate come from protein.


Front and back of isopure unflavored protein powder

Isopure Unflavored Whey Isolate Protein Powder is my top choice for increasing daily protein intake without adding extra calories. 

This low-calorie protein powder delivers 25 grams of protein in each 100-calorie serving, with no carbohydrates or fat. You can be sure that 100% of the calories come from protein. 

With nearly three times the protein of one large egg at approximately $1.56 per 29-gram serving, it is a convenient and accessible source of high-quality protein!

Dymatize ISO100

Dymatize ISO100 Hydrolyzed Protein Powder picture of front and back.

The next runner-up for the lowest calorie protein powdered is  Dymatize ISO100 Hydrolyzed Protein Powder. 

It offers a unique solution with 110 calories per serving, 25 grams of protein, and only 2 grams of carbohydrates and 1 gram of fat per serving; this product is rated among the highest in quality protein powder. 

91% of its calories come from protein, and with an approximate cost of $1.58 per serving, you get a quality protein source that is reasonably priced.  

I will mention that you can find cheaper options for protein, like chicken breast, which is 2.99 -4.99 per pound, equal to $0.75-$1.24 per serving. 

Nutricost Whey Protein Isolate

Nutricost Whey Protein Isolate (Unflavored) is an excellent choice for those looking for a low-calorie, high-protein option. 

Each serving contains 130 calories and packs 30 grams of protein. This means that 92.3% of the calories in this product come from protein. 

Not only that, but each 33-gram serving is easy on the wallet at around $1.01. Seeing that 92.3% of the calories come from protein, there is 0 grams of carbohydrate and 0.5 grams of fat. 

If you’re searching for an ideal source of low-calorie whey protein isolate powder that is cost-effective, Nutricost Whey Protein Isolate (Unflavored) 5LBS is an excellent option to consider.

It’s Just! – Whey Protein Isolate 

It’s Just! Whey Protein Isolate is last on our list because of the price per serving. Other than that, this is a quality, low-calorie protein powder. 

Coming in at 120 calories per serving and 30 grams of protein. That means 92.3% of the total calories come from protein. Which is equivalent to Nutricost. 

Each serving weighs 33 grams and costs about $1.76. I must say that is the 4th highest cost per serving on this list of low-calorie protein powders.

With that said, It’s Just! Whey Protein Isolate has only one gram of carbohydrate and fat. This means that the remaining 6.8% of calories (10 calories) come from these two macros.

NOW Sports Nutrition, Whey Protein Isolate

Now Sports Nutrition Whey Protein Isolate is another great low-calorie protein powder that is relatively cost-effective. 

Each serving weighs 28 grams and has 110 calories with 25 grams of protein. This is simply whey protein isolate powder, with 91% of the total calories coming from protein. 

The remaining ten calories come from >1 gram of carbohydrates and 0.5 grams of fat.  

With each serving averaging to about $1.27, Now’s whey isolate is a quality, low-calorie protein powder that is cost-effective. 

Low-calorie whey protein concentrate 

Next on our low-calorie protein powder is whey protein concentrate. While whey isolates are slightly lower in calories, whey concentrate is not much higher and provides a similar quantity of protein.  

On average, whey protein concentrate is 126 calories per serving and provides 24.75 grams of protein. This also means that 79.8% of the calories in whey concentrate come from protein.

Optimum Nutrition Gold Standard 100% Whey

Optimum Nutrition 100% Whey Protein powder picture of front and back.

I must admit that Optimum Nutrition is my favorite low-calorie protein powder. It is in that perfect intersection of low-cost, low-calorie, and high-protein. 

At 120 calories per serving and 24 grams of protein per serving, 80% of the 120 calories come from strictly protein. 

And a single serving size of 31 grams contains just 2 grams of carbohydrate and 1.5 grams of fat – perfectly proportioned for those looking to get their macros right! 

Best of all? The cost averages ~$1.06 per serving, and when Costco runs a sale, you can get the cost down to about $0.75. (54.99 for a 5lb container) 

Dymatize Elite

The next runner-up is Dymatize Elite 100% Whey Protein Powder Gourmet. It stacks up to optimums whey protein in its price point but does have 20 extra calories. 

With 140 calories per serving and 25 grams of protein per serving, you can get a large proportion of your daily protein intake with one scoop. 

Each scoop weighs 34 grams, and 72% of the calories come from protein while supplying 2 grams of carbohydrates and 3 grams of fat. 

Low-calorie and cost-effective, this powder will run you an average of $1.04 per serving

Nutricost Whey Protein Concentrate

Nutricost Whey Protein Concentrate (Vanilla) checks all the boxes its low-calorie, high protein, and super affordable. 

With 25 grams of protein per serving and 130 calories, offering you 77% of its total calories from whey protein.

Each serving size is 33 grams, and you get 2 grams of carbohydrates and 2.5 grams of fat, totaling about 30 calories that do not come from protein. 

Plus, with a cost of approximately $0.74 per serving, this is one of the most affordable options for quality, low-calorie protein powder available today!

Naked WHEY 

Naked Whey 100% Grass-Fed Unflavored Whey Protein Powder is a little bit pricey than the other whey protein concentrates on this list but offers one of the highest protein-to-calorie ratios. 

Low in calories with 120 per serving, this powder also contains 25 grams of protein, 3 grams of carbohydrate, and 2 grams of fat. In other words, 83% of calories come from protein.  

With a serving size of 30 grams, this product is valued at about $1.19 per serving!

Low-calorie plant-based protein powder

Plant-based protein powder is another popular protein supplement that offers a decent amount of protein while vegetarian and vegan-friendly. While they do not compare to whey protein in the amount of protein-per-calorie ratio, you can get low-calorie options with some brands. 

The average plant-based protein powder is 154 calories and 24 grams of protein. The protein percentage is 62% of the total calories. 

Although plant-based protein vs whey concentrate or isolate is higher calorie and lower overall protein. These options are great for those that follow a vegetarian or vegan diet.

Orgain Organic Vegan Protein Powder

orgain protein powder picture front and back

Orgain Organic Vegan Protein Powder, Vanilla Bean is an excellent option for those looking for a low-calorie protein powder that fits into their vegetarian or vegan lifestyle. 

With 150 calories per serving, this protein powder contains 21 grams of protein and 15 grams of carbohydrates and 3 grams of fat. Meaning about 56% of the 150 calories come from protein. 

Each serving size is 46 grams (2 scoops) and costs about $1.49 per serving. This plant-based protein powder balances cost-effectiveness and quality nutrition to help you reach your health goals.

Dymatize Vegan

Dymatize Complete Plant Protein

Dymatize has released a newer product called Complete Plant protein, which includes several plant proteins to combat each individual’s incomplete amino acid profiles. 

At 150 calories and 25 grams of protein, we look at 67% of the total calories coming from protein. The remaining calories come from 5 grams of carbohydrates and 2.5 grams fat.  

Each serving is 38 grams and costs $1.99 per serving. That is a higher price point however you are getting a higher protein content per serving.

OWYN Only What You Need

OWYN Protein Powder offers an average protein percentage per calorie ratio for plant-based proteins. With 140 calories and 20 grams of protein, this powder contains about 57% of its calories from protein!

Each serving size is 34 grams, costing you about $2.14 each.

Vega Sport Premium Protein Powder

Vega Protein picture of front and back.

Vega Sport Premium Protein powder is the highest protein percentage per calorie ratio of all the plant-based protein powders on this list. With 170 calories and 30 grams of protein, you’re looking at an impressive 71% of the total calories coming from protein! 

Each serving size is 41 grams and costs about $2.15 per serving, the most expensive powder on this list. However, it has additional nutritional benefits, such as a low carbohydrate content of 4 grams per serving and 3.5 grams fat.

Collagen Protein Powder: Vital proteins 

I have to mention collagen protein because it is on the first blog post listed for low-calorie protein powders. 

Collagen is not a complete protein and should not replace a protein source, supplemental or not.

Frequently Asked Questions

How many calories are in a protein shake with milk

The number of calories in a protein shake with milk will vary depending on the type of protein powder and the fat percentage in the milk. 

A whey protein shake mixed with 2% milk has 242 calories. If you are looking for a lower-calorie option mixing a whey protein isolate with fat-free milk will provide 191 calories. 

How many grams of protein are in a protein shake with milk

The amount of protein that a protein shake with milk will depend on the type of protein and the type of milk used.

A whey protein isolates mixed with fat-free milk will provide the most protein at 34 grams. 

Which protein powder has the lowest calories?

The protein powder with the lowest calories is the unflavored whey protein isolate from Isopure. This protein powder has 100 calories with 25 grams of protein, indicating that this product is 100% protein and contains no calories from carbohydrates or fats. 

Which is the best protein powder for weight loss?

The best protein powder for weight loss will depend on preference and quality. A protein powder you enjoy drinking will increase the likelihood of drinking it consistently. A quality protein powder will contain all nine essential amino acids. 

Can you lose weight on protein powder?

Yes, you can lose weight with protein powder. You may lose weight because protein is a filling macronutrient that also preserves lean body tissue. Replacing a snack or meal with a protein shake has been shown to aid weight loss.

Final thoughts 

Low-calorie protein powder is an excellent way to get the high-quality nutrition your body needs without having to worry about extra calories. 

Various protein powders are available on the market, such as whey protein isolate, whey protein concentrate, and plant-based proteins. 

You can find the perfect option depending on your dietary preferences and budget! 

Always check labels carefully before purchasing any supplement, and consult a healthcare professional. With these tips in mind, I hope you enjoy finding the right low-calorie protein powder!


Remember: this post is for informational purposes only and may not be the best fit for you and your personal situation. It shall not be construed as medical advice. The information and education provided here is not intended or implied to supplement or replace professional medical treatment, advice, and/or diagnosis. Always check with your own physician or medical professional before trying or implementing any information read here. 

Noah Quezada is a Registered Dietitian Nutritionist located in Denver, Colorado. Over the course of more than a decade, he has gained extensive experience in helping clients manage their weight through in-person sessions. Noah is also the 2023 President of the Colorado Academy of Nutrition and Dietetics.

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