Protein 101

Popular culture has convinced us that we need to consume a lot of protein, usually from meat, poultry, dairy, fish, beans, nuts and seeds. This blog is a deep dive into protein. But, we don’t want you to get bogged down in the numbers. If you’re a relatively healthy adult and you’re eating a wide variety of fruits, vegetables, and whole grains along with small amounts of protein-rich foods, you’re likely getting plenty of protein to meet your needs!

If you want to know more, let’s dive in.

What is protein? Protein is one of three macronutrients our bodies use for energy. The other two are carbohydrate and fat. Protein is necessary for building and repairing cells, creating enzymes and antibodies, and performing other essential functions.

Where Do I Get Protein? There are twenty amino acids that are the building blocks of protein. Our bodies can make most of the amino acids, but there are eight we cannot make: these are called the essential amino acids, and we easily get them from both plant and animal foods. You are probably familiar with animal protein sources. They include beef, pork, lamb, chicken, turkey, fish, seafood, dairy, and eggs. But did you know all plant foods contain protein? In fact, every plant food contains all 20 amino acids. Some plant foods contain more protein than others. Beans, legumes, lentils, nuts and seeds contain the highest amounts of protein of all plant foods, followed by whole grains, then vegetables, and lastly, fruit. You may have heard you need to combine foods to make a complete protein from plants, like rice and beans. However, if you are eating a wide variety of plant foods throughout the day, combining is not necessary. The variety will provide adequate amounts of all amino acids to meet your protein needs.

General Recommendations To meet minimum basic needs for healthy adults, the U.S. Recommended Dietary Allowance (RDA) is 0.8 grams (g) per kilogram (kg) of bodyweight or 0.36 g per pound (lb) of body weight. For the average sedentary man, this amounts to around 56 g per day or a 6 ounce (oz) chicken breast. The average sedentary woman could meet her protein needs with a 5 oz chicken breast. Another rule of thumb for the general population is that getting 10-15% of calories from protein is sufficient, even for people with an active lifestyle.

Estimating Activity-Specific Protein Needs Protein needs are calculated based on body weight and activity type. Using this table, you can calculate the estimated range of protein that will meet your daily needs.

Type of Individual Grams of Protein per pound of body weight Grams of protein per kilogram of body weight

Sedentary Adult 0.36 0.8

Recreational exercise, adult 0.5 - 0.7 1.1 - 1.6

Endurance athlete, adult 0.6 - 0.7 1.3 - 1.6

Adult building muscle mass 0.7 - 0.8 1.6 - 1.8

Athlete restricting calories 0.8 - 0.9 1.8 - 2.0

Estimated upper intake, adult 0.9 2.0

*To convert lb into kg, divide body weight in lb by 2.2.

EXAMPLE: A recreational exerciser weighing 150 lb is estimated to adequately meet all protein needs by consuming a range of 75 to 105 g of protein per day. A range is calculated because individual needs will vary. Calculation: 150 lb x 0.5 g of protein per lb of body weight = 75 g of protein. 150 lb x 0.7 g/lb = 105 g protein.

How Much Is Too Much? It is possible to eat too much protein. The guidelines set the upper limit at 0.9 g per lb of body weight or 2 g per kg of body weight. Regular overconsumption of protein can negatively impact kidney, bone, and liver health, and contribute to kidney stone risk. In addition, people who eat a diet high in animal protein have an increased risk of heart disease and colon cancer, although a diet high in plant protein does not carry the same risks.