Protein builds muscle, boosts the immune system, and helps with weight loss - here's how much you need a day

Protein builds muscle, boosts the immune system, and helps with weight loss - here's how much you need a day
Steak is one of the best sources of protein.grandriver/Getty Images
  • Protein is made up of amino acids and is one of three types of essential macronutrients.
  • Protein is important because it builds muscle, digests food, and keeps skin firm and healthy.
  • You need to eat at least 0.36 grams of protein per pound of body weight daily.

The human body consists of tens of thousands of proteins, which are found in every cell of your body, making them an essential part of anyone's diet. Protein also provides a number of other health benefits. Here is how much you need and the best protein food sources you can buy.

What is protein?

Protein is one of three types of essential macronutrients, the other two being carbohydrates and fats. They are made up of amino acids, organic compounds, and they help grow and maintain the body's tissues - including muscles, tendons, blood vessels, and skin.

Therefore, eating protein every day is essential to maintain key bodily functions like building tissues and digesting foods.

Why is protein important?

Unlike carbohydrates or fats, your body doesn't store protein, meaning you need to eat it every day. Protein is also the only macronutrient that contains nitrogen, a structural component of amino acids that humans can only acquire through food.

Protein's health benefits include:


How much do you need every day?

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The US Food and Nutrition Board of the Institute of Medicine recommends a daily protein intake of at least 0.36 grams of protein per pound of body weight, or 0.8 grams per kilogram.

Therefore, an adult who weighs 150 pounds should eat at least 54 grams of protein a day. Calorie-wise, protein should take up about 10% to 35% of your daily intake.

However, some people may need more protein, like:

Most American adults get enough protein, though some 46% of adults over 70 don't have adequate intake. Not consuming enough protein results in a protein deficiency, which can reduce your muscle mass, impair your immune response, and reduce bone density, leading to osteoporosis.

"Certain fad diets set us up to have a health halo over all types of protein, thinking more is better. But as in any macronutrient, if you have an overabundance of protein, it will equate to extra calories and be stored as fat or adipose tissue," says Christine Patorniti, a registered dietician and certified diabetes educator in Centennial, Colorado.


Important: A 2020 study review found eating more than the recommended daily allowance (RDA) won't help you lose weight or gain lean muscle unless you are also doing strength training or in a calorie deficit.

Types of protein

Both animal and plant foods have protein. However, animal products are complete proteins, containing all of the nine essential amino acids your body needs to function. Meanwhile, plant-based sources of protein are more likely to be incomplete, lacking a sufficient quantity of one more of the essential amino acids.

Therefore, vegetarians and vegans will need to eat a variety of plant proteins to take all in the amino acids plus other nutrients their bodies need, says Patorniti.

Related Article Module: 8 of the best plant-based sources of protein, according to dietitians

However, compared to animal protein sources, plant proteins may promote lower blood sugar and cholesterol levels. In fact, a large 2020 review found people who ate diets high in plant-based protein had an 8% lower risk of death from any cause over 32 years.

High protein foods

FoodServing Size Protein grams (g) % Daily Value (DV)
Beef, cooked3 ounces (oz) 23.446.8%
Chicken breast, boneless, skinless3 oz25.951.8%
Tuna fish3 oz24.849.6%
Tofu, raw1/2 cup1020%
Large egg1/2 cup6.2512.5%
Black beans1 cup15.2 30.4%
Cheddar Cheese 1 slice6.7813.56%
Peanuts, dry roasted1 oz 7 14%

A powder or drink supplement can help you meet your daily protein requirement, but can also be high in sugar, salt, and preservatives, which could negatively impact your health, says Kelsey Mangano, PhD, an assistant professor and Nutrition Program Director at the University of Massachusetts Lowell. Meanwhile, protein from whole foods contains other important nutrients like vitamins, fiber, and iron.


Insider's takeaway

Protein is a macronutrient composed of amino acids that your body relies on for many critical functions like building muscle and fighting infection. You should aim to eat at least 0.36 grams of protein per pound of body weight

a day, but this varies depending on weight, age, activity level, and goals High protein foods come from both animal and plant sources. Whichever type you choose, make sure to include a variety of sources throughout the day.

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