Does Protein Powder Make You Gain Weight? Let’s Divulge The Facts


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Protein shakes are a popular recovery tool for athletes who have just finished a hard weightlifting workout in the gym, a long run, or some other type of vigorous exercise. 

By simply adding protein powder to milk, plant-based milk, or even water and then shaking it up in a shaker bottle on the go, you can have a protein-packed recovery drink to help begin the refueling and rehydrating process within minutes after finishing your last rep or mile.

If you are training at home, you can also add protein powder to a more robust smoothie or protein shake to make a more filling, nutrient-dense post-workout meal.

But is protein powder good for you? Does protein powder make you gain weight? Do protein shakes make you fat?

In this article, we will discuss whether protein shakes or protein powder makes you gain weight or gain fat and factors that affect whether you will gain weight from drinking protein shakes or using protein powder in your diet.

We will cover: 

  • What Is Protein Powder?
  • Does Protein Powder Make You Gain Weight?

Let’s jump in!

Chocolate and vanilla protein powder.

What Is Protein Powder?

Protein powder is an umbrella term to describe any type of powdered protein isolate, typically intended to be used by athletes, though many non-athletes may also use protein powder.

There is a wide range of types of protein powder, from single-ingredient protein powders to products that are a blend of different sources of protein along with other nutrients, flavoring, and sweeteners.

Common single-ingredient protein powders include whey protein powder, casein protein powder, pea protein powder, collagen protein powder, egg white protein powder, hemp protein powder, and brown rice protein powder. 

Many plant-based protein powders are a blend of protein isolates from several different plant-based protein sources, such as brown rice, pea, sunflower seed or pumpkin seed, hemp, and sometimes soy. 

This is because most types of plant-based proteins are incomplete proteins, meaning that the proteins in their natural state are missing at least one of the nine essential amino acids. 

Six different types of protein power.

Although hemp and soy are exceptions, hemp protein powder tends to have a distinctive and somewhat grassy taste, making it unappealing to some, and soy protein powder is a little controversial due to concerns about the potential estrogenic effects of a diet high in soy. 

This is not to say that choosing a hemp protein powder or soy protein powder is necessarily bad for you; hemp is quite nutritious and also high in fiber and omega-3 fatty acids. If you don’t mind the taste, it can be one of the best vegan protein powder options and also a great choice for omnivores, given the rich nutrient profile. 

The research on soy is quite inconclusive, but most studies have concluded that soy is nutritious and does not cause adverse “feminizing effects” in males or females. With that said, many of the vegan protein powders use a blend of brown rice and pea protein along with protein from some type of seed or another source. 

Most plain, unsweetened single-ingredient protein powders or unsweetened plant protein blends provide about 80-120 calories per serving, with 18-25 grams of protein or so, depending on the type of protein and serving size.

Someone scooping protein powder from a large tub.

With the exception of hemp protein, which adds a modest amount of heart-healthy omega-3 fats, nearly all of the calories from unsweetened protein powders come from the protein isolate or concentrate used, making these products a lean protein source. 

Many protein powders have additional nutrients added to the formulation to boost the vitamins, minerals, or other specific nutritional attributes. 

For example, vegan protein powders might have synthetic vitamin B12 added since this vitamin is essential for energy production and often deficient in plant-based diets since the majority of natural sources of vitamin B12 are animal products.

It’s also quite common for whey protein powder or even vegan protein powders to add MCT oil or omega-3 fatty acids. Spirulina, chlorella, or other greens blends or fruit and vegetable powders may be added to boost the antioxidants, vitamins, and minerals.

Depending on your specific nutritional goals and potential deficiencies, protein powders with these types of additives might be more or less desirable to you than basic lean protein powders.

A person pouring a scoop of protein powder into a shaker.

Adding these types of ingredients rounds out the nutritional profile somewhat but doesn’t change the caloric content all that much. Adding 2-3 grams of MCT oil or other healthy fat will increase the calories per serving by about 30 calories.

To improve the palatability of protein powders, many are flavored and sweetened with natural and/or artificial flavors and sweeteners. 

This is definitely something to pay attention to when you are choosing which protein powder to buy.

While vanilla extract and cocoa powder won’t necessarily add many calories, peanut butter powder can. Artificial flavorings also introduce chemicals and fillers you might not want to put into your body.

Sweeteners are really where things get dicey. Table sugar or other forms of natural sugar like coconut sugar will increase the carbs and calories in protein powders significantly.

A person making a protein shake.

Most protein powders use artificial sweeteners to keep the carbohydrates, sugar content, and calories low. 

Although certain non-caloric sweeteners like stevia and monk fruit extract are derived from natural sources, evidence about long-term safety is lacking. Plus, as these sweeteners are thousands of times sweeter than regular sugar, they are thought to cause sugar cravings in much the same way as real sugar

Sugar alcohols, like erythritol and mannitol, are often found in low-calorie chocolate or vanilla protein powders (or other flavors). However, sugar alcohols are very poorly absorbed and can lead to digestive distress.

Artificial sweeteners like sucralose are extremely sweet and have been linked to adverse health effects. Try to avoid protein powders with this ingredient.

Lastly, some protein powders are formulated as meal-replacement shakes, so they are much higher in calories, carbohydrates, and fat.

These types of meal replacement protein powders might have upwards of 350 calories per serving, if not more.

Scooping protein powder from a container.

Does Protein Powder Make You Gain Weight?

So, do protein shakes make you fat? Does whey protein make you gain weight?

Making a protein shake with whey protein powder, or any type of basic protein powder, won’t inherently make you gain weight.

Whether or not you gain weight by drinking protein shakes or using protein powder depends on your overall diet and caloric intake, your physical activity, the specific protein shake recipe you are using, or the type of protein powder (regular lean protein powder versus meal replacement protein powder), and how often you’re drinking protein shakes.

When you’re in a caloric surplus (eating more calories than you’re burning in a day), you will gain weight.

If you’re currently maintaining your weight and start adding protein shakes to your diet without making compensatory reductions in calories elsewhere in your diet or doing more exercise, protein shakes can cause weight gain.

If you drink protein shakes and remain in a caloric deficit (burning more calories than you are consuming per day), you’ll lose weight.

Chocolate protein powder.

The protein shake recipe will affect how quickly or significantly you will gain fat or lose weight by drinking protein shakes.

A basic protein shake made with water or unsweetened almond milk and a lean protein powder will only provide about 110-140 calories at most.

Since you have to consume an excess of 3,500 calories to gain one pound of fat, you’d have to drink almost 30 protein shakes without adjusting your diet or activity level before you gain one pound.

On the other hand, protein shakes with whole milk, nut butters, bananas, or meal replacement protein powders contain way more calories and result in faster weight gain. These shakes can have 250-500 calories or so each.

Therefore, if you want to gain weight, using protein powders with more calories and then blending them up into protein shakes with rich ingredients like peanut butter, bananas, and whole milk will help you get a nutritious, calorically-dense protein shake to support muscle growth and bulking.

On the other hand, if you don’t want to gain weight but still want to drink protein shakes or use protein powders, choose lean protein powders and mix them with water, skim milk, or unsweetened plant-based milk.

Ensure your overall diet has calories to allocate in your “budget” to your protein shake, keeping in mind that these low-calorie protein shake recipes only contain about 150 calories or less (slightly more with skim milk).

So, when answering does protein powder make you gain weight, well, it depends. Use protein powder according to your specific goals to make it work for you either way.

For some great protein shake recipes, check out our very own here.

A person shaking a protein shake.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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