Eating protein or using protein powder does not make you "bulky," or lead to excess weight gain.

Gaining weight or "bulk" occurs when you consume too many calories. 

Since most protein powders are only between 100-150 calories per serving, it's highly unlikely that they alone would cause you to gain unwanted weight. In fact, a higher protein take can often lead to better satiety, or feelings of fullness, which can be useful for weight loss. 

Instead, unwanted weight gain tends to be the result of several factors and lifestyle choices. 

Why Adequate Protein Intake Is A Healthy Habit

Sleep. Eat protein at every meal. Move daily.

If you were to boil down the habits that are the foundation of healthy living, you could easily start with those three tips and see tremendous results. 

Protein is a key part of all of your cells. It's connected to your longevity. The health of your body. And it plays a key role in fat loss, muscle gain, and high performance. But, unless it’s combined with excess calories, protein alone won't make you bulky.

And yet, protein is still one of the most misunderstood nutrients. Whether it's bodybuilding culture or the endless number of protein memes, eating or supplementing with protein is about much more than building muscle. If you're struggling to understand how and why to add protein to your diet, here's what you need to know. 

Why Protein Doesn't Make You Bulky

Protein is an essential building block and the ultimate fuel for muscle growth and recovery. That’s because it’s the nutrient that helps repair and rebuild muscle when it’s broken down during a workout.

But, in order to get “big,” you need two things:

  1. an intense training routine specifically designed for muscle growth 
  2. a lot of calories.

Any type of weight training is not designed to add bulk or muscle mass. If it were that easy, everyone in the gym would look like a model or bodybuilder.

That means the average person—even when eating more protein—won’t achieve the same “bulk” as a bodybuilder unless they adopt an intense training regimen or consume the number of calories necessary to grow that much muscle, says Alonzo Wilson, founder, and director of training at New York group fitness studio Tone House.

“You’re going to have to work out extremely hard to get that type of bulk,” Wilson says. “Having some protein after you work out is not going to make you Arnold Schwarzenegger.”

In fact, it’s more likely that protein will help function as a weight-loss stimulant if it’s paired with exercise. Among fats and carbohydrates, protein is the least likely macronutrient to convert to fat in the body’s stores, says Richard Kreider, Ph.D., director of the Exercise and Sports Nutrition Lab at Texas A&M University.      

Because of protein’s complex molecular composition, the nutrient digests slowly, he says, so it burns more calories to break down than fat and carbs do. Protein packs an enduring source of energy to power a strenuous workout, and it helps slow hunger and maintains fullness.

How Much Protein Do You Need?

Kreider says it would be impossible to build the same amount of muscle as bodybuilders without consuming upward of 4,000 to 6,000 calories every day, more than two times the average adult’s recommended caloric intake per the U.S. Department of Health.

While there’s no such thing as “bad protein,” different types promote protein synthesis more than others and have more amino acids that can be used by your body for a variety of goals, Kreider says.

The average adult who regularly performs exercises needs about 1.2 to 1.8 grams per kilogram of body weight per day, Kreider says, while bodybuilders usually ingest double their body weight in grams of protein every day to balance their extreme lifting schedule.

“Think of your body as a car,” Wilson says. “Your car needs fuel to go. When you’re working out—or driving long miles—fuel is getting depleted. Protein puts fuel back into your body, but also helps you gain lean muscle and shred fat.”

What Protein Is Best For You?

Remember, all protein is important for your body. That's because your body breaks protein down into amino acids. Then, your body uses those amino acids to fuel recovery, fat loss, muscle building, and even maintain the youthful appearance of your hair, skin, and nails. 

So, instead of thinking about good vs. bad protein, it's best to understand that you'll likely need protein from a variety of sources to make sure you get enough protein in your diet, regardless of whether you're bulking up, cutting down, or just following a healthy eating plan. 

Animal proteins, such as fish, eggs, lean meats, and dairy are considered “complete protein” since they contain all the essential amino acids, including leucine, isoleucine, and valine, which stimulate muscle repair and increase levels of leptin, the hormone that regulates hunger.

Whey protein, a dairy byproduct typically sold as a powder, is absorbed more quickly into the bloodstream and rapidly speeds up the muscle recovery process after an intense workout. Casein protein, another byproduct of cheese-making, is digested more slowly than whey, so it’s better suited to synthesize protein throughout the night. Athletes looking to build muscle mass fast tend to prefer whey, Kreider says.

Though plant proteins, like beans, rice, and nuts, are “incomplete proteins” due to missing links in the amino chain, vegans can build just as much bulk as their meat-eating counterparts without slowing muscle recovery. Combining protein sources throughout the day paired with healthy carbs and fats ensures amino acid requirements are met, Kreider says.

Or, you can eat complete plant proteins -- like pea protein -- which contain all of the essential amino acids your body can't build on its own.

Protein benefits virtually everyone across varying activity levels and age groups, though needs increase as a person’s activity level increases.

For those looking to build muscle and burn fat, Wilson recommends getting the majority of protein from whole foods like salmon, lean turkey, eggs (yolk included), yogurt and beans to supply most to all the protein necessary for prime functioning.

Then, you can use protein powders (like whey or plant) to add convenience and make sure you hit your protein goals and provide your body with everything it needs to function its best.