Key Takeaways

  1. A high-protein diet and protein powders aren’t inherently unhealthy. A high-protein diet confers a number of health benefits, and a high-quality protein powder is a great way to bolster your protein intake.
  2. Protein powders aren’t as nutritious as whole foods and can bother your stomach if over-consumed. This is why you want to use them as dietary supplements and not staples.
  3. For optimal health, keep your protein powder intake to less than 20% of your daily calories, and have no more than 40 to 50 grams of powdered protein in one meal.

Protein powders and drinks are more popular than ever for good reason:

They’re convenient, tasty, affordable, and in most cases, well-digested, well-absorbed, and rich in essential amino acids vital to gaining and preserving muscle and strength.

They also make eating a high-protein diet a cinch. A few meals per day with a protein shake or two thrown into the mix gets the job done, regardless of how much protein you need to eat.

Now, while we know that protein powder isn’t harmful per se, is eating too much harmful? And if so, how much can you eat every day before it becomes a problem?

Well, according to some people, if you drink too many protein shakes, you’re asking for all sorts of trouble, ranging from an upset stomach to severe digestive disorders, nutritional deficiencies, and even kidney damage.

Others say such claims are nonsense because protein powder is just dried food, and therefore doesn’t fundamentally affect the body any differently than other forms of protein like chicken, eggs, or milk.

Who’s right?

Well, the short story is this:

There’s nothing fundamentally wrong with drinking a couple protein shakes per day. Getting a large portion of your daily calories from protein, however, is probably a bad idea.

And in this article, you’ll learn why.

By the end, you’re going to understand why people think eating too much protein powder is bad for you, what science has to say about it, and the upper limit of how much protein powder you should eat every day.

Let’s get started.

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Why Supplement With Protein Powder?

If there’s one thing most fitness “gurus” agree about, it’s that a high-protein diet is best.

And they’re right.

Studies show that eating plenty of protein . . .  

What constitutes a “high-protein diet,” though?

Well, according to research conducted by scientists at McMaster University, a protein intake of 1.3 to 1.8 grams per kilogram of body weight per day (0.6 to 0.8 grams per pound of body weight per day) is adequate for maximizing muscle and strength gain.

They did note, however, that more protein may be optimal if you’re doing frequent and intense resistance training workouts, and especially when you’re also restricting calories for fat loss.

A study conducted by scientists at The University of Western Ontario came to a similar conclusion. 1.6 to 1.8 grams of protein per kilogram of body weight per day is probably enough for most athletes, but higher intakes may be appropriate based on numerous factors relating to energy balance, carbohydrate availability, exercise intensity, duration, and type, protein quality, training history, gender, age, nutrient timing, and more.

All this is why I recommend that you generally eat between 0.8 and 1 gram of protein per pound of body weight per day, and that you go slightly higher (around 1.2 grams per pound per day) when cutting.

(And in the case of the very overweight/obese, protein intake can simply be set at 40% of total daily calories.)

Now, that means eating 150 to 200+ grams of protein per day for most men and ~100 to 150 grams per day for most women, and while you don’t need a protein supplement to hit those targets, it sure does help.

Another major benefit of protein powder is the most common forms like whey, casein, soy, and rice and pea are well-digested, well-absorbed, and rich in essential amino acids, making them particularly beneficial to us fitness folk.

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Is Eating a Lot of Protein Powder Bad for You?

too much protein powder side effects

The mainstream media has been buzzing with anti-protein propaganda for several years now.

Eat too much protein, we’re told, and we can damage our kidneys and increase the risk of osteoporosis and even cancer. Such allegations are great for creating headlines that get clicks and shares, but they simply don’t have science on their side.

For example, research shows that people with pre-existing kidney damage or dysfunction should restrict their protein intake, but a high-protein diet has never been shown to cause kidney damage.

Furthermore, a high-protein diet has been shown to both lower blood pressure and improve blood glucose control in diabetics, which would decrease the risk of kidney disease, not increase it.

Warnings that a high-protein diet increases the risk of osteoporosis are even stranger, as studies have shown it directly helps prevent the condition.

And as far as cancer goes, this is a story that mostly qualifies as fake news. To quote Dr. Spencer Nadolsky from our Science Advisory Board:

To even suggest that eating protein is as bad as smoking is pure sensationalism…

A more accurate headline for this study would have been “High protein for those between 50 years to 65 years old who have poor diet and lifestyle habits may be associated with increased cancer risk.”

If you want to know why, check out Dr. Nadolsky’s in-depth analysis of the science over at Examine.com.

That’s just protein, though. What about protein powder?

Well, your body processes the protein from protein powder the same way it does the protein from beef, peas, or broccoli, so the idea that protein powder is somehow uniquely harmful is fiction.

This is why multiple studies have shown that increasing protein intake from protein powders can improve blood sugar, body composition, bone density, and other health markers.

That said, there have been scandals that give prospective protein powder consumers pause, like the Consumer Reports revelation that several brands of protein powder including BSN, Muscle Milk, MuscleTech, and GNC contained high levels of arsenic, lead, cadmium, and mercury.  

If you were to eat several servings of these powders everyday, the heavy metals could accumulate in your body and increase the risk of kidney damage and other health problems.

While protein contamination isn’t as prevalent and severe as some people would have you believe, it does highlight an important reality of supplementation: you’re putting your health in the hands of the supplement companies you buy from and the people who run them, and you often don’t know what you’re really buying and ingesting.

This is why you should do your due diligence before putting pills and powders into your body, and given how shady the supplement industry is, you should assume a company whose products you’re considering guilty until proven innocent.

Dig in and find out…

  • How long has the company been around for? What’s their reputation like online?
  • Have they been caught lying or cheating in the past?
  • Who specifically creates the formulations and what are their backgrounds? Can you even find out?
  • Who runs the company and what are they all about?
  • What’s in the products and why?
  • What are people saying about their products online?

And only buy once you’re satisfied with the answers.

Anyway, getting back on topic:

The bottom line is that eating a lot of protein, whether from whole foods or powders, isn’t unhealthy unless you’re already very unhealthy and unwilling to change your lifestyle.

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How Much Protein Powder Is Too Much?

symptoms too much protein

You now know why protein powders are a multi-billion dollar market, and why many of the supposed health risks are overblown.

As with anything, though, if you take protein supplementation too far, you can experience negative side effects like nutritional deficiencies and gastrointestinal distress.

One of the main benefits of protein powder is that it’s mostly protein (it contains very little carbohydrate or dietary fat).

This is great news for your macros, but not so great news for the nutritional quality of your diet because many whole-food sources of protein are also great sources of vitamins, minerals, and other micronutrients.

For instance, eggs are one of the most nutrient-rich foods you can eat, legumes are chock-full of prebiotic fiber and microminerals, and meat contains beneficial compounds like L-carnitine, CoQ10, iron, and creatine, all of which are missing from most protein powders.

Therefore, if you’re getting too many of your daily calories from protein powder (30 or 40% or more) and not ensuring your remaining calories are extremely nutrient-dense, you’re likely to develop nutritional “holes” in your diet that can cause health problems over time.

Eating too much protein powder—and especially in one sitting—isn’t ideal either, because it can cause gas, bloating, and cramping.

Powders are digested faster than whole-food proteins, so if you gulp down too much, some of the protein molecules can make their way into the large intestine only partially digested, resulting in GI distress.

This problem is rather unique to protein powder because of how easy it is eat. Foods that require chewing and are more filling than powders, making them harder to overconsume, whereas a protein shake packed full of a couple chicken breasts’ worth of protein can be downed in a matter of seconds, placing an immediate and intense demand on your digestive system to properly process it all.

Whey protein can be particularly troublesome in this regard, as many people can’t comfortably digest a hefty dose of dairy protein in one sitting. This is less of an issue with whey isolate protein, which doesn’t contain lactose, but it can still occur.

So, all things considered, here are my recommendations for protein powder intake:

  1. Try not to get more than 20% of your daily calories from protein powders.
  2. Try not to have more than 40 to 50 grams of protein powder in one sitting.

If you follow those simple guidelines, you’ll reap the maximum benefits from protein supplementation and avoid most if not all of the potential downsides.

Read: How to Find the Best Protein Powder For You

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The Bottom Line on How Much Protein Powder You Should Eat

A high-protein diet and protein powders aren’t inherently unhealthy.

In fact, research indicates exactly the opposite—a high-protein diet confers a number of health benefits, and a high-quality protein powder is a great way to bolster your protein intake.

That said, protein powders aren’t as nutritious as whole foods and can bother your stomach if over-consumed. This is why you want to use them as dietary supplements and not staples.

All you have to do is keep your protein powder intake to 20% of your daily calories or less, and have no more than 40 to 50 grams of protein powder in one meal, and you should have no issues.

If you’d like to learn more about individual types of protein powders and determine which is best for you, check out this article.

What’s your take on eating too much protein powder? Have anything else to share? Let me know in the comments below!

+ Scientific References