Protein is often hailed as the building block of life, essential for everything from muscle growth to immune function. But how much protein does a human really need? With conflicting advice from diet trends, fitness influencers, and health organizations, it can be difficult to determine the right amount for optimal health. Factors like age, activity level, and overall health play a crucial role in individual protein needs.
Jana Wieser, Registered Dietitian and Nutrition Therapy Director at Pullman Regional Hospital, discusses the science behind protein requirements and provides practical guidance on how to ensure you're getting the right amount for your body’s needs.
Why Is Protein Important?
Protein is a crucial macronutrient that provides the body with energy and plays a vital role in various functions beyond just muscle growth. It is made up of amino acids that contribute to essential bodily processes, including digestion, blood clotting, hormone regulation, and immune defense. While many associate protein primarily with building muscle, it also supports skin, bones, and connective tissues.
The amount of protein a person needs each day depends on factors like age, activity level, and overall health. Per Wieser, the baseline recommendation for sedentary individuals is about 0.8 grams per kilogram of body weight per day to support basic metabolic functions. However, most adults benefit from consuming 1 to 1.2 grams per kilogram daily.
“If you're somebody who is more active or doing a lot of weight lifting or training for an athletic event, you may need even more than that, like 1.2 to 1.6 grams per kilogram,” she states. “However, research shows that after about 1.6 grams per kilogram, you're going to see diminishing returns.”
Top Protein Sources
Protein can be found in both plant-based and animal-based sources, debunking the common misconception that vegetarians struggle to get enough protein. Wieser notes that rich plant-based sources include grains, legumes, nuts, seeds, and lentils, while animal-based options include meat, poultry, fish, and dairy products like milk, yogurt, eggs, and cottage cheese. However, foods like sour cream and butter do not provide significant protein. With a well-balanced diet, it’s easy to meet protein needs from a variety of sources.
In regard to whether or not plant-based protein is “enough,” Wieser assures plant protein is an acceptable way to fulfill protein needs. “It's really important to make sure you're getting a variety of plants in your diet if you're not using any animal sources of protein, but it's still a perfectly healthy and good way to get protein,” she notes. “You can get all the protein you need from plants.”
Too Little vs. Too Much Protein: Finding the Right Balance
Most Americans get enough protein, but certain groups—such as teenage girls, the elderly, and those experiencing food insecurity—are at higher risk of deficiency. Not consuming enough protein can lead to muscle loss, weakened immunity, poor wound healing, and brittle skin, hair, and nails.
On the other hand, excessive protein intake is generally not harmful for healthy adults, but those with conditions like chronic kidney disease, high blood pressure, or diabetes should be cautious, as too much protein can strain the kidneys. Additionally, high animal protein consumption—especially from sources high in saturated fat—may increase the risk of cardiovascular disease and cancer, while plant-based proteins offer fiber and other beneficial nutrients.
Overall, protein intake should be balanced and sourced from a variety of foods to support overall health. Wieser also cautions about intaking too much protein in one sitting.
“As Americans, we tend to eat a lot of protein at night. Try to space that throughout the day for optimal absorption. Aim for getting twenty to thirty grams in the morning, at lunch, and at dinner. Even if it's less, having some snacks throughout the day can contribute to your protein consumption and can help your body absorb it better. Your body really can't absorb more than twenty to forty grams at one time,” she clarifies. “If you're a meat eater, and having a huge steak at dinnertime, you're really not going to be able to utilize as much as you're eating.”
