Protein isn't just fuel for gym-goers -- it's the powerhouse behind nearly every vital function in your body. While fats and carbohydrates often steal the spotlight, protein works quietly behind the scenes as a critical nutrient with an impressive list of benefits.
According to dietitian and clinical director of Berry Street, Marjorie Nolan Cohn, "Protein is a macronutrient because it has 'macro' importance. It has many key functions within the body, [including] supporting our muscles, hormones, digestion and absorption, bones and even breathing. Altogether, proteins are involved in nearly every process that sustains life." Given its significance, it's only natural to wonder how much protein you should be eating.
As a dietitian with years of experience in hospitals and outpatient clinics, my answer to the "how much protein" question is, unfortunately, "It depends." Official guidelines recommend 46 grams of protein daily for adult females and 56 grams for adult males. However, these numbers don't account for individual factors like activity level or health status. Research suggests that most adults need far more than the recommended amounts. For example, higher protein intake in older adults has been shown to combat the typical loss of muscle mass and strength, helping them maintain independence longer.
To dive deeper into this, I reviewed the latest research, tapped into my clinical expertise and consulted with two registered dietitians to better understand daily protein needs and identify the best foods to include in your diet. Here's what I found.
Along with carbs and fats, protein is one of the three essential macronutrients -- nutrients you need in larger quantities -- and serves as the main building block of your body. Found in every cell, protein is a vital component of your bones, muscles, skin, organs, enzymes and hormones.
Proteins are constructed from chains of smaller molecules called amino acids. Of the 20 amino acids your body needs, it can produce 11 on its own. The remaining nine, known as essential amino acids, cannot be made by your body and must be obtained through your diet.
Foods that provide all nine essential amino acids in sufficient amounts are called complete proteins. These are typically found in animal-based foods like meat, fish, eggs and dairy, as well as some plant-based sources like quinoa, soy and chia seeds. Including complete proteins in your meals ensures your body has the full range of amino acids it needs to function optimally.
While the list of protein's functions is extensive, here are some of its key roles:
Although protein isn't your body's primary energy source -- that title belongs to carbs -- it can be broken down and converted into energy when necessary, proving its versatility as a nutrient.
Protein requirements are not one-size-fits-all; they vary based on several circumstances and can change throughout your lifetime.
Some of the primary factors that determine how much protein you need include:
Protein needs are nuanced and can vary significantly. According to the 2020-2025 Dietary Guidelines for Americans, approximately 10%-35% of your calories should come from protein.
Of course, certain populations have higher protein needs, including older adults, those who are pregnant or breastfeeding and highly active individuals.
Here are the current Recommended Daily Allowances (RDA) for various groups:
Keep in mind that the RDA is the minimum amount of protein your body needs to perform its basic functions. Most people's actual daily needs are likely higher.
Research suggests that adults over 65 may need nearly double the RDA for protein, depending on their activity level and health status.
The best way to assess your protein needs is by working with a dietitian or other health care professional. However, there are ways to estimate your goal amount of protein using either your weight or goal calorie intake.
To determine your daily protein requirements based on body weight and specific conditions, multiply your weight in pounds by the appropriate factor listed below:
You can also assess your protein needs based on the amount of calories you consume -- though, fair warning, there is some extensive math involved.
To calculate your daily protein requirement:
Example calculation: If your daily caloric goal is 1,800 and you decide that 15% of your calories should come from protein:
This is a rough estimate. It's advisable to consult with a health care provider or dietitian to tailor your protein intake to your specific individual needs.
No matter your dietary preferences, there are an array of high-protein options to fuel your body.
"Animal protein sources are a tried-and-true protein powerhouse," says Cohn. These foods are rich in protein and are considered complete proteins, meaning they contain all nine essential amino acids your body needs.
Examples include:
Keep in mind that not all animal proteins are created equal. Heart-healthy options like skinless chicken breast and fatty fish like salmon are better choices than fattier cuts of beef or processed meats. Fatty fish also provide omega-3s, which are beneficial for heart health. On the other hand, consumption of heavily processed meats, such as bacon, sausages and hot dogs, should be limited due to their association with an increased risk of certain cancers.
Most plant-based proteins are incomplete, meaning they lack one or more essential amino acid. However, by eating a variety of plant proteins throughout the day, you can easily meet your needs for all nine.
Examples of plant-based protein foods include:
While meat alternatives like Beyond Burger and Impossible Burger are popular plant-based protein options, they tend to be heavily processed and high in sodium or saturated fat. While convenient, these products shouldn't be the cornerstone of your diet.
While it's always best to prioritize whole foods to meet your protein needs, some people may find it challenging to consume enough protein throughout the day. If that applies to you, adding a protein powder to your diet can be a convenient and effective solution.
If you're unsure whether you're meeting your protein requirements, consult with a registered dietitian or health care professional.
That said, specific demographics or groups are more likely to benefit from a protein powder due to their increased protein needs or difficulty meeting their intake goals. The following categories of individuals might get a better boost from protein powder:
Cohn suggests that "when looking for a protein powder, aim to include one without added sugar or a laundry list of ingredients. Rather aim for a protein powder that contains simple, straightforward formulas or ingredients." It's also a good idea to look for products that are third-party tested to ensure label accuracy.
Keep in mind that most protein powders are formulated for adults and are not safe for children. Additionally, people who are immunocompromised, pregnant or breastfeeding should talk with an ob-gyn or other health care professional to make sure the product they choose is safe and appropriate.
We tested 18 protein powders to identify the best options for every need. You can check out our findings here, but our top picks for Best Overall and Best Plant-Based both came from the same brand: Naked Nutrition.
Getting enough protein is just one piece of the puzzle. For optimal health, you'll also want to follow these guidelines:
Studies show that a high-protein diet can support weight loss by reducing appetite, increasing feelings of fullness and boosting metabolism. It can also help you lose body fat while retaining muscle mass. Aim for 0.6-0.9 g of protein per pound of body weight to support weight loss.
The International Society of Sports Nutrition recommends consuming 0.6-0.9 g of protein per pound (or 1.4-2.0 g per kilogram) of body weight. For someone weighing 150 pounds, this would mean aiming for 90-135 g of protein per day.
Yes, eating too much protein can have negative side effects. As Jessica M. Kelly, dietitian and owner of Nutrition that Heals, explains, when we eat more protein than our bodies need, that protein is either "broken down and used for energy, or stored as fat. [Too much protein] can also cause gastrointestinal distress and put extra strain on the kidneys." The latter is particularly true for individuals who may be at a higher risk for kidney disease.
For most healthy adults, protein powder is safe to take daily. That said, there are some things to keep in mind. According to Kelly, "Make sure you know the amount of protein per serving and that you are indeed consuming the recommended amount. There are many different protein powders out there, and you want to make sure you are getting a quality brand, so look for one that is third-party tested for potency, heavy metals and contaminants."
Also, keep in mind that consuming protein powder regularly for long periods may cause unwanted gastrointestinal side effects, including upset stomach, bloating, nausea, diarrhea or constipation.