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Whey Protein vs Mass Gainer: 7 Important Differences

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Whey Protein vs. Mass Gainer - heydayDo featured image

Unfamiliar with what makes a mass gainer powder a completely different animal than a typical whey protein?

Well in this whey protein vs mass gainer article I compare & contrast the two, sharing with you several of what I think are sharp & important differences between them.

Knowing their distinctions is useful if you’re considering supplementing your diet with either of them, since the benefits & effects you could get from taking one or the other may not be at all the same.

Since these two supplements are different they have different purposes, and so I will also share what I think are the best uses for whey protein & mass gainer supplements in your own diet.

test tubes green - heydayDo icon

Science resources included

As is my custom here on heydayDo, I will provide links to all of the relevant sports science and medical resources, clinical studies, & nutritional data used in this article.


What’s coming up

I’ll be giving you my list of differences along with providing examples & background for each one along the way.

And for some of the nutrition comparison examples I thought it’d be cool to compare two products from the same company — one their mass gainer and the other chosen from one of their whey protein powders.

Most of the big names in the protein powder universe put out a mass gainer too, so I’ll probably be using a pair from the likes of Optimum Nutrition, Dymatize, MusclePharm, etc.


Note: Any product images or product names in blue will open in a separate tab onto their product pages on Amazon if you want to check today’s price, read reviews, etc.


Whey vs. Mass Gainer: One thing vs. Many things

Bottom line: Whey protein powder is just one dairy-based ingredient, but most mass gainers have several more ingredients in them than just whey.


Whey protein powder comes from a single source — a cow — and it’s created by being a by-product of the cheese-making process used by the dairy industry. (1)

Here is an example of a clean whey powder from Opportuniteas.

Opportuniteas Gras-Fed Whey Protein Concentrate powder

It has only one thing in it (whey protein), so they don’t even have to post an Ingredients list on their Supplement Facts label:

Opportuniteas whey back panel showing it's only 1 ingredient - heydayDo image

Nothing there.

Contrast that with this mass gainer label from Dymatize’s Super Mass Gainer:

Dymatize Super Mass Gainer ingredients - heydayDo image

As you’ll see in the next section on ingredients, even most decent-quality whey protein powders that have been flavored & artificially sweetened still have far fewer “working parts” than a mass gainer.


Whey protein vs. mass gainers: different ingredients

Bottom line: Mass gainers usually have more ingredients in them than whey protein powder products, and many companies also spike their gainers by adding vitamins, minerals, &/or athletic performance-enhancing supplements like creatine, glutamine, taurine, etc.


No doubt there are a boatload of whey protein powders in all shapes, sizes, & flavors flooding the market these days.

Take a look at this:

Amazon search for whey protein powder - heydayDo image

And despite the wide variety that whey powders come in, at the end of the day they are a product built around the same single ingredient, whey protein.

For this Whey vs. Mass Gainer article we’ll be comparing the ingredients of the #1 selling protein powder in the world — Optimum Nutrition Gold Standard Whey — to the #1 selling mass gainer in the world, Optimum Nutrition Serious Mass.
Optimum Nutrition Gold Standard Whey Double Rich ChocolateOptimum Nutrition Serious Mass powder, chocolate

Here’s what’s in Serious Mass, and note that all of the vitamins, minerals, & performance supplements you see on its Supplement Facts panel have been added, thus they are not naturally-occurring except for the calcium & a bit of the sodium (both from the milk protein.)

ON’s Serious Mass ingredients

O.N. Serious Mass vitamins minerals & ingredients - heydayDo image

I count 42 ingredients in Serious Mass.


ON’s Gold Standard Whey ingredients

By contrast there are only 9 things in Optimum Nutrition’s flagship whey protein powder:

Optimum Nutrition Whey ingredients - heydayDo image

Note also that there are no additional supplements added to Gold Standard Whey like there were in Serious Mass.


Whey & mass gainers have different macronutrient profiles

Bottom line: The largest macronutrient in most mass gainers is carbohydrate, while whey powders are highest in protein.

And many mass gainers have a very high percentage of carbs in them just as the macros in most quality whey protein powders are similarly dominated by protein.


Although it will contain small (or only trace) amounts of carbohydrates & fat, whey protein powder is essentially just that: protein.

Big surprise there I bet, huh?

And this is true regardless of what type(s) of whey it is made from, be it

  • whey concentrate,
  • whey isolate,
  • hydrolyzed whey,
  • whey peptides,
  • or some blend of those.

A quick way to determine what the macronutrient percentages are for any protein powder is to head to its Supplement Facts panel, grab some numbers, & do a little simple math (adding & dividing).

Let’s do this for both our mass gainer & whey powders that were in the last example, then compare the numbers side by side.

This will clearly illustrate to you just how nutritionally different these two types of powders really are.


Here’s the Supplement Facts label of Gold Standard Whey:

Optimum Nutrition Gold Standard Whey Nutrition Facts

Here’s what we get in a single serving:

  • Protein – 24 grams
  • Carbs – 3 grams
  • Fat –  1.5 grams

Adding them together, our total macros in that serving is 28.5 grams, so now we just divide each of the macros by the total (28.5 grams).

That’ll give us the percentage of each one:

* Protein 24/28.5 = 84%

* Carbs 3/28.5 = 11%

* Fat 1.5/28.5 = 5%


As you can see, ON’s Gold Standard whey powder mostly consists of protein, and by a huge margin too.

Now let’s look at how different the macros in their mass gainer are.


Serious Mass Supplement Facts

Serious Mass macros - heydayDo image

Here’s what we get in a single serving — which is gigantic by the way — as you’ll see a little later:

  • Protein – 50 grams
  • Carbs – 252 grams
  • Fat –  4.5 grams

Adding them together, our total macros in that serving is a whopping 306.5 grams, so like before we just divide each macro by the total.

That’ll give us the percentage of each one:

* Protein 50/306.5 = 16%

* Carbs 252/306.5 = 82%

* Fat 4.5/306.5 = 2%


Comparing macros: Serious Mass v. Gold Standard Whey

This chart below paints a clear picture of the macronutrient differences between whey protein powder & a typical mass gainer.Macronutrient comparison between ON's Serious Mass & Gold Standard Whey - heydayDo image


Whey & mass gainers have different serving sizes

Bottom line: One of a mass gainer’s main roles is to provide additional calories to your existing diet.

So it’s probably not a big surprise that its serving size is a lot larger than your typical whey powder’s serving size.

And in many cases, the mass gainer’s serving is SEVERAL TIMES larger than most whey protein products.


Here’s a look at the serving sizes from Gold Standard Whey & Serious Mass, and I’m sure you can guess who’s who.

Notice how Serious Mass’s serving is actually eleven times bigger than Gold Standard Whey’s:

Serving size comparison between Gold Standard Whey & Serious Mass - heydayDo image


And here are a couple of pictures that show just how big a Serious Mass scoop is & remember, two heaping scoops is its suggested serving size.

That’s the Gold Standard whey scoop that is easily fitting inside Serious Mass’:

Size of scoop that comes with Serious Mass and Pro Gainer - heydayDo image

Translating their grams per serving into ounces, Gold Standard whey protein is just a little over an ounce & Serious Mass’s serving size weighs 12 ounces, or 3/4 of a pound.


Mass gainers have a lot more calories than whey

Bottom line: Given the difference in serving sizes we just looked at — 336 grams vs. 30 grams — it’s no wonder that there’s a big difference in their calorie counts too. And in fact, all mass gainers by their very definition are high-calorie supplements, whereas whey protein is a low-calorie product.


On a per serving basis, Optimum Nutrition’s Gold Standard whey protein powder has only 120 calories, while their Serious Mass powder contains 1,250 — that’s more than 10 times as many calories.

Calorie per serving comparison of Gold Standard whey protein & Serious Mass gainer - heydayDo image


Now let’s compare Gold Standard to Optimum Nutrition’s more balanced mass gainer named Pro Gainer.
Optimum Nutrition Pro Gainer powder

Pro Gainer has 650 calories per serving, so the difference in calories is still over 500% (5 times as many in the gainer), 650 vs. 120 in the whey protein powder.

Calories in ON's Pro Gainer - heydayDo image

Is whey vegan? No.

Whey protein is a dairy by-product that comes from cow’s milk, and is therefore not vegan.

But there are a few well-regarded vegan mass gainer powders on the market, like Naked Vegan Mass.

amazon fields=”B07XTQKYG1″ value=”thumb” image_size=”large” image_alt=”Naked Vegan Mass”]


While the mass gainers & the whey protein powders we’ve looked at in this article used whey as the main protein source, Naked’s Vegan Mass & other vegan mass powders use plant-based sources like pea, quinoa, peanut flour, Sacha Inchi (Inca peanut), etc.

And most mass gainers get those really high amounts of carbohydrate by using maltodextrin, which is a high glycemic index carb manufactured out of corn, rice, or tapioca root.

Maltodextrin is used because sports science studies have shown that ingesting high glycemic carbs along with protein immediately following intense exercise (like weightlifting) greatly aids muscle recovery. (2)

Vegan mass gainers use various plant-based sources for their carbs, with this VeganMass product above using blends featuring oat bran, pea starch, quinoa, buckwheat, & more.


Whey & mass gainers’ best uses are different

Bottom line: Mass gainers are high-calorie supplements designed to help athletes & weightlifters who are training with some intensity add lean muscle weight.

Whey protein powder is designed to simply provide supplemental protein to someone’s diet.


Let’s recap the biggest nutritional differences between mass gainers & whey protein powders that we’ve covered:


Different ingredients

Mass gainers & whey protein have different ingredients, with whey powders containing mostly just that — whey — while gainers contain several other things including high glycemic carbs & additional supplements.


Different macro profiles

Mass gainers are usually quite high in carbs, whey powders are high in protein.


Different amounts of calories

Mass gainer single servings typically contain several times the calories of a serving of whey protein.


Knowing these three sharp distinctions makes it easy to guess that the best uses for whey protein & mass gainers would probably be different from each other as well, and they are.


Mass gainers are for gaining weight, increasing strength, & adding muscle

Mass gainers have the combo of high glycemic carbs & rapid-absorbing protein (whey blends) to assist the intense exerciser, be they an athlete who weight trains, or a serious weightlifter.

As I mentioned up in the vegan section, post-workout consumption of high GI carbs with protein is very beneficial for those who really get after it in their fitness training. (5)

Mass gainers also provide the necessary “in between meal” & post-workout calories to keep the serious trainee in a calorie surplus, which will help her or him gain weight & build muscle.


Whey powder is a protein supplement

On the other hand, whey is simply a high-quality, fast-absorbing, lean (low calorie) protein source that is ideal for a healthy way to bump up your daily protein intake if you’re not getting enough from your meals.

While a mass gainer has a lot of calories in it as we saw earlier, clean whey powder is a high-protein, low calorie source — since it is essentially both fat-free & carb-free.


Wrapping up

Related articles here on heydayDo

How to Use a Mass Gainer, How It Works, Side Effects, & More

How To Build Muscle & Gain Weight If You’re An Ectomorph

Make Your Own Homemade Protein Shake Recipes for Weight Gain

Lil Boji with ON's whey protein & mass gainer best-sellers - heydayDo image

I hope that my article on comparing mass gainer powders to whey protein products is useful to you, and I wish you well on your fitness journey.

Let’s go.

– greg

About The Author

heydayDo author Greg Simon

Hi! I’m Gregory Simon.

Fitness training & nutrition researching since 1982. ISSN (International Society of Sports Nutrition) Pro Member. Surfer. Organic food grower. Congenital heart disease survivor (so far). is my wellness blog that’s about encouraging a healthy lifestyle as we age.

I share my fitness training experience as well as the sports science research I’ve done on the many benefits strength building, exercise, & good eating habits offer us.

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