Protein is one of three macronutrients and an important part of the diet. It is necessary to build strong muscles and produce certain hormones and enzymes. The body does not store protein, so it is important that people consume enough based on their age, health, sex, and activity level.
The recommended daily allowance (RDA) of protein for adults over 19 is
This article will explore what protein is, where it comes from, and how much the body needs. It will also explain how to calculate protein intake and whether it can help build muscle and aid weight loss.
Proteins are made of amino acids, which link together in different combinations to create new proteins that help build muscles and bones. Proteins also create energy and produce enzymes and hormones.
The body produces 11 amino acids, known as non-essential amino acids. There are nine amino acids that the body cannot produce, known as essential amino acids that it must get from food instead.
‘Complete’ proteins are a good source of essential amino acids.
Protein comes from animal and plant sources.
Animal sources, including chicken, beef, fish, or dairy products, contain all the essential amino acids and are high quality or complete protein sources.
Plant proteins, including beans, lentils, and whole grains, are incomplete proteins. Although they may not contain all the amino acids, they are still valuable protein sources.
Soy products derive from soya beans. They include edamame, meat alternatives, and tofu and contain essential amino acids, making them high quality, complete protein sources.
According to the
One gram (g) of protein contains around 4 calories. A person who eats 2,000 calories daily and gets 20% of their calories from protein would consume 100 g of protein, totaling 400 calories.
How to calculate protein intake
Using an online calculator, such as the one provided by the U.S. Department of Agriculture, may help people establish protein requirements.
Alternatively, the following calculation can provide the proper target for protein consumption in either grams or calories.
- First, it’s important to know how many calories a person is likely to consume per day. An example is 2,300 calories.
- A person should choose the percentage of the diet that will be protein. In this example, it will be 20%.
- Multiply the total calories by the percentage of protein to get the number of calories from protein. 2300 x .20 = 460.
- Divide the calories from protein by 4 to get the total grams of protein. 460 / 4 = 115.
Using this example, a person consuming 2,300 calories per day, aiming for 20% of their calories to come from protein, will need to consume 115 g of protein per day.
Including protein as part of a balanced diet has been proven to assist with weight loss.
High quality protein combined with exercise can help build muscle. Eating within 30–60 minutes of finishing exercise may be the most beneficial for building muscle. During this time, skeletal muscles make better use of nutrients in food than they do 3 hours after exercising.
The current recommended daily allowance (RDA) for protein is set at a level that prevents
Active individuals may eat up to 2 g per kilogram (kg) body weight of protein per day. The most active individuals may go as high as 3.5 g per kg body weight. Eating high protein levels for long periods may cause digestive, renal, and vascular problems.
The RDA of protein for females ages 19-50 who are pregnant is still
For teens under 18 who are pregnant, the RDA is 10-30% of total daily caloric intake from high quality protein sources.
The proper amount of protein is important for maintaining balance in the body and rebuilding muscles and bones.
Protein can come from many sources, but only protein from animal sources or soy contains all the essential amino acids the body needs in a single food item. Combining incomplete protein sources makes it possible to get all of the essential amino acids a person needs.
A person should aim to get 10-35% of their total daily calories from protein unless they are very active or seek to build muscle. In this case, calculate 2-3.5g per kg of body weight of protein per day.
A person can talk with a dietitian or nutritionist to discuss their optimal protein intake.