In recent years, protein has taken center stage for American consumers, with many people looking to increase their intake to boost health, lose weight, or gain muscle.
In fact, recent research found that over 70% of Americans are actively seeking to add protein to their diets. Yet, despite protein’s soaring popularity, many myths and misconceptions persist.
With the help of registered dietitian Jessica Leonard, we set the record straight on all things protein: What it is, why it’s important, how much you really need, the best sources, and the role protein may play in helping you maintain a healthy weight.
What Is Protein?
Protein, along with carbohydrates and fat, is one of three macronutrients your body needs to function. When we eat protein, it is then digested or broken down into amino acids.
While it may sound a bit complicated, according to Jessica, “Amino acids are simply the ‘building blocks’ our bodies use to make all of the different proteins needed to build and repair muscle, produce hormones, support our immune system, and many other essential functions.”
Incredibly, there are more than 10,000 different proteins our body creates from these building blocks to make up our hair, muscles, bones, skin, and other tissues—and none of this could happen without the protein we get from food, which makes it all possible. (Note: You may have heard there are 20 amino acids in total. Our bodies can manufacture 11 of them, but nine of them are called “essential,” meaning we must get them directly from food. Learn more.
How Much Protein Do You Need?
One of the most common misunderstandings about protein is how much of it is required to maintain health. One reason is that many of the recommendations are expressed in grams or in grams per kilogram of body weight—measures that aren’t intuitive for most people in the U.S.
For example, the Recommended Dietary Allowance (RDA) for protein is “0.8 grams per kilogram of body weight”, which is approximately “0.36 grams per pound”. Hence the problem: These numbers just don’t mean a lot to most people!
To translate, this means a person weighing 165 pounds (75 kilograms) would target just over two ounces (about 60 grams) of protein daily, according to the Mayo Clinic. However, it depends on size and gender, among other things.
For an average woman, the amount is just a little over 1 1/2 ounces of daily protein, or about 2 ounces for an average man. Of course, to get this amount of pure protein, it takes more than an ounce or two of food since even high protein foods aren’t 100% protein.
For example, a skinless chicken breast, one of the highest protein foods, is only about one-third protein by weight. So, what does 1 ½ to 2 ounces (or 46 to 56 grams) of protein look like in terms of actual food portions?
Here are a few examples that convert these sometimes-confusing measures into real food.
| Example 1 | Example 2 | Example 3 |
| 5 oz Greek yogurt (16g) | 2 boiled eggs (12g) | 1 cup oatmeal (5g) |
| ½ cup grilled tofu (22g) | ¾ cup chili with beans (12g) | Grilled cheese on wheat (16g) |
| 1 cup black beans (15 g) | 3.5 oz chicken breast (32g) | 6 oz grilled salmon (30g) |
| Daily Total: 53g protein | Total: 56g protein | Total: 50g protein |
Does One Size Fit All?
It’s important to realize that the RDAs or daily guidelines represent the minimum required to prevent deficiency, so they’re not necessarily ideal for everyone. Protein needs vary significantly based on age, activity level, and health status.
For example, athletes, people recovering from illness or injury, and pregnant women may require more protein.
Athletes are the prime example we hear about most often. People engaging in ongoing intense physical training may require as much as 50-100% more protein compared to those of us who are not training for athletic competition.
But Jessica stresses that the extra protein beneficial to competitive athletes and others participating in intense training supports activity levels far above what most normally active people experience day to day.
Research on aging has also revealed that higher protein intake may be beneficial for adults as they age, helping to combat the muscle loss associated with getting older. So, experts now recommend as much as 25-50% more protein for an older person of the same size, to help preserve muscle mass and strength.
Muscle mass typically peaks at around age 30 or 40 and declines thereafter, with the amount of decline picking up as people reach their 60s and 70s. Rates of muscle mass decline can reach as high as 8% every decade. That’s why Jessica emphasizes that, “For older adults, it’s particularly important to eat protein with meals and snacks as loss of muscle mass is a precursor to many health issues.” Read more.
For personalized guidance on how much protein you need, USDA has a customizable meal plan tool to help you meet your specific protein and total calorie needs based on your age, gender, and activity level.
Jessica also points out that there are millions of people worldwide who are unable to meet their protein needs due to poverty and food insecurity. In the U.S. and most other developed countries, it’s relatively uncommon for healthy adults to have a protein deficiency. In fact, many Americans are overconsuming protein, especially from animal-based foods.
How Much Protein Is Too Much?
While protein is vital for overall health, more isn’t always better. Consuming excessive amounts of protein can lead to multiple health issues.
“A diet too high in protein can put stress on the kidneys, especially in people with pre-existing kidney conditions,” says Jessica. “Overconsumption can also lead to digestive problems, cardiovascular issues, and unwanted weight gain, as excess protein is converted into fat if not used for energy or muscle repair.”
Some people take protein consumption to an extreme with strict keto or ultra-high protein diets, which can crowd out other important macronutrients. Jessica advises to avoid eliminating any macronutrient group.
“It’s best to take a balanced approach to meals and snacks that include healthy carbs, healthy fats, and adequate—but not excessive—amounts of lean protein spread evenly throughout the day,” she says. “If you are considering protein levels much higher than recommended, it’s best to talk to your health care provider first.”
What Are the Best Sources of Protein?
There are two main categories of dietary protein sources: Animal-based and plant-based. Both provide essential nutrients, but their composition and effects on the body differ slightly.
Animal-Based Proteins
Meat, poultry, fish, eggs, and dairy products are considered “complete” proteins because they contain all nine essential amino acids (the ones our bodies can’t make on our own). These sources are also typically rich in vital vitamins and minerals like vitamin B12, iron, and zinc.
However, red meat can be high in saturated fat, which has been linked to cardiovascular issues when consumed in excess. Fish, especially fatty varieties like salmon and sardines, offer the added benefit of Omega-3s, which promote heart health.
Plant-Based Proteins
Beans, legumes, whole grains, nuts, seeds, and soy products are excellent sources of protein, with many additional nutritional benefits from vitamins, minerals, and phytonutrients.
While plant-based proteins are often labeled “incomplete” because most lack one or more essential amino acids, this is easily addressed by eating a variety of plants.
Jessica suggests, for example, mixing rice and beans together to create a complete protein. She adds, “Some plant-based foods like quinoa and soy are naturally complete proteins. Plant proteins are also typically high in fiber, which supports digestive health and helps to reduce cholesterol.”
Plant-base proteins also have the benefit of being better for the planet, with significantly lower carbon and other greenhouse gas emissions than are associated with animal-based proteins.
Another bonus? Jessica recommends choosing plant-based protein to help save money at the supermarket. “Not only are there many healthy plant-based protein options, but most are also budget-friendly compared to animal proteins like fish, poultry and beef,” she notes.
So, Which Is Better?
For optimal health, if you have no other restrictions—cultural, allergies, etc.—Jessica recommends including both plant and animal protein sources in your diet as each provides a different set of nutrients.
The Dietary Guidelines for Americans recommends eating a variety of protein foods, including seafood, lean meats and poultry, eggs, legumes, nuts, seeds, and soy foods.
However, if you wish to avoid all animal sources of protein, you can still meet your protein needs with knowledge and planning. In this case, it can be helpful to work with a registered dietitian to ensure that you are meeting all your nutrient needs.
Can Protein Help You Reach or Maintain a Healthy Weight?
Protein has been shown to play a key role in weight management.
One of the reasons for this is that protein is more satiating than carbohydrates or fats, meaning it helps you feel fuller for longer. This can prevent overeating and help support people who are trying to reduce their calorie intake to lose excess weight.
Jessica also points out that protein helps preserve muscle mass during weight loss. “It’s crucial to maintain muscle as part of a healthy weight loss program,” she says, “because muscle tissue burns more calories than fat tissue, even at rest.”
While some studies suggest that high-protein diets can aid in weight loss, the research is mixed. What’s clear is that incorporating adequate protein into a balanced diet, along with regular physical activity, can support healthy weight management.
Common Protein Myths
MYTH 1: More Protein Automatically Means More Muscle
One of the most persistent myths surrounding protein is the belief that more protein leads directly to more muscle.
While it’s true that protein is critical for muscle repair and growth, increasing protein intake without engaging in resistance training or other forms of exercise will not lead to increased muscle mass.
Building muscle requires a combination of strength training and adequate nutrition, including but not limited to protein.
MYTH 2: Plant Proteins Are Inferior to Animal Proteins
Another common misconception is that plant proteins are somehow less effective than animal proteins because they are often incomplete. This belief is untrue.
As noted earlier, eating a variety of plant-based proteins throughout the day can provide all the essential amino acids. Additionally, plant-based diets have been shown to offer numerous health benefits, such as reduced risks of heart disease, lower cholesterol levels, and better digestive health due to the high fiber content.
MYTH3: Protein Supplements Are Necessary for Most People
Protein supplements such as shakes and bars are heavily marketed, especially to fitness enthusiasts, but they are not necessary for most people.
With few exceptions, individuals can meet their protein needs through a balanced diet of whole foods. Supplements are convenient but should be reserved for those who truly need them, such as athletes with very high protein requirements, older adults with diminished appetites, or people with restrictive diets.
Understanding and Balance
Protein is an essential nutrient that plays a fundamental role in maintaining and repairing the body’s tissues, supporting the immune system, producing hormones, and much more.
By understanding more about protein and focusing on getting a balanced diet that includes a variety of protein sources, most people can meet their needs without the need for supplements or excessive consumption.
Note: Since everyone’s health history and nutritional needs are so different, please make sure that you talk with your doctor and a registered dietitian to get advice about the diet and exercise plan that‘s right for you.