By Registered Dietitian Mia Syn, MS, RDN

Protein is one of three essential macronutrients that make up the human diet and plays a key role in the creation and maintenance of every cell in the body. Most Americans easily meet their protein needs but not all food sources of protein are created equal. Here is everything you need to know about the importance of protein and where to get it.

What is protein?

Protein is found throughout the body including muscles, bones, skin and hair. It is made up of over 20 building blocks called amino acids – some of which the body can make and others which are considered “essential” and must come from the food we eat. Besides cells, protein makes up the enzymes that power many chemical reactions in the body. 

How much protein do we need?

The amount of protein you need in your diet will depend on a range of factors including your age, sex, height, weight, level of activity, health status and life stage. The Dietary Guidelines for Americans recommends that healthy adults aim for around 5-to-7-ounce equivalents of protein daily which can be met through a variety of foods including meat, poultry, eggs, seafood, nuts, seeds, beans, peas, lentils and even vegetables.

What foods are protein found in?

Animal foods are the most concentrated source of protein. In addition to protein, they also provide variable amounts of fat and minimal carbohydrates.

  • Meat

  • Fish

  • Poultry

  • Eggs

  • Dairy products

Plant foods also provide protein to varying degrees, with soy products being the most concentrated source. Plant protein foods also tend to provide carbohydrates and varying amounts of fat.

  • Soy foods like tofu, tempeh and edamame

  • Beans and lentils

  • Whole grains

  • Nuts and seeds

What is high quality “complete” protein?

Complete protein foods contain all the amino acids needed to make new protein in the body while incomplete proteins lack one or more of the essential amino acid building blocks. While animal-based foods are good sources of complete protein, most plant-based food sources are considered incomplete, with a few exceptions such as hemp seeds and quinoa. If you choose to restrict animal-based foods, you can still meet your protein needs by varying the plant-based protein foods you consume.

10 reasons why protein is important

  1. Protein is the building block of life

Protein is essential to every cell in the body and is needed for cell repair and synthesis, making it especially important for growth and development in children, teens and pregnant women.

  1. Protein can help with weight loss and management

Protein is a satiating macronutrient. Numerous studies have shown that high protein diets may be a successful tool in aiding weight loss and weight management. (1)

  1. Protein helps with immune function

A protein deficiency has long been known to impair immune function and increase the susceptibility to disease. Protein plays a vital role in activating immune cells and producing antibodies. (2)

  1. Protein is important for bone health

People lose bone mass and density with age, especially women after menopause. Studies suggest that a high protein intake may help reduce hip fracture risk and play a beneficial role in bone mineral density maintenance in older adults. (3)

  1. Protein helps with muscle recovery

There is a reason why body builders and exercise enthusiasts consume protein after a tough workout. Studies show that protein plays a key role in helping to repair and strengthen muscle tissue after exercise. (4)

  1. Protein helps repair the body after injury

When you have a wound or injury, think of protein foods as medicine for repair. Studies suggest that high protein intake may help speed up recovery. (5)

  1. Protein helps preserve muscle mass with age

Sarcopenia, or age-related muscle loss, is a natural part of aging. Consuming a sufficient amount of protein with each meal may help prevent or slow it. (6)

  1. Protein may boost metabolism

Multiple studies suggest that high protein intake may boost metabolism and increase the number of calories you burn. (7)

  1. Protein may help curb sugar cravings

Some studies have shown that adding protein to meals may help curb sugar cravings because of its ability to stabilize blood sugar and prevent spikes and dips. (8)

  1. Protein supports hair, skin and nails

As the structural component of skin, hair and nails, protein is an important “beauty nutrient”.


Protein is an essential macronutrient that plays an important role in the body with benefits ranging from muscle recovery and bone health, to weight loss and immunity. While animal foods are considered high quality complete protein sources, you can still meet your needs from plant foods by varying the types of foods you consume.










Mia Syn, MS, RDN Bio:

Mia Syn is nationally recognized registered dietitian and nutrition expert, Health Advisory Board Member at Forbes and founder of Nutrition By Mia, a popular online wellness destination. She has a master’s in human nutrition from Columbia University and has been featured by dozens of major media outlets including Cosmopolitan and SHAPE and was named one of the top registered dietitians to follow on Instagram by Women’s Health Magazine.