A Day’s Protein Necessity

Even if you don’t know what protein is or how much you need, you probably know how it makes you feel. From a filling egg scramble for breakfast to a tasty steak (or tofu) for dinner, you’re probably familiar with the long-lasting satisfaction that protein provides. And, as we’ll see, protein lives up to its reputation.

You know protein is good for you, but you may have some questions. Why does your body need it? How much and when should you eat protein? And what about your activity level? Here’s what protein does and how much your body needs (A Day’s Protein Necessity)

Even if you don’t know what protein is or how much you need, you probably know how it makes you feel. From a filling egg scramble for breakfast to a tasty steak (or tofu) for dinner, you’re probably familiar with the long-lasting satisfaction that protein provides. And, as we’ll see, protein lives up to its reputation.

You know protein is good for you, but you may have some questions. Why does your body need it? How much and when should you eat protein? And what about your activity level? Here’s what protein does and how much your body needs.

What is protein?

Protein is a macronutrient (i.e., nutrients the body needs in sizable amounts). Protein, unlike carbs and fat, is not a major energy source, although it does provide four calories per gram. A building block in the body, protein plays a crucial role in growth and development.

The protein content of almost all animal-derived products—meat, poultry, eggs, dairy, and fish—allows them to be classified as protein sources. Many plant-based foods also contain protein. Beans, peas, nuts, and seeds, for example, have a lot, while vegetables and grains have less, according to the FDA (FDA). Whole grains have more protein than refined grains, which lack the protein-rich part of the grain.

Amino acids make up proteins. According to the FDA, there are 20 different amino acids in total. Nine of the 20 are essential amino acids, meaning the body can not produce them and must obtain them from food. According to the U.S. National Library of Medicine, the body can synthesize the other 11 amino acids from the essential ones or by breaking down proteins.

According to the FDA, a complete protein contains all nine essential amino acids. Soybean is a complete protein. An incomplete protein lacks or has low levels of any of the essential amino acids. Most plant proteins are incomplete.

This means that a wide variety of incomplete proteins can provide all of the essential amino acids for vegetarians, vegans, and plant-food lovers. According to the FDA, incomplete proteins are often deficient in one or two amino acids, so they can often compensate. Grains, for example, are low in lysine, while beans and nuts are low in methionine. With beans and rice or wheat toast with nut butter, you get all the amino acids found in chicken.

According to the U.S. National Library of Medicine, eating foods in combinations at meals is no longer necessary as long as you eat a variety of complementary incomplete proteins throughout the day. 

Why do we need it?

That’s no exaggeration. It’s in every cell in your body, including your muscles.

Dr. Colleen Tewksbury, Ph.D., M.P.H., R.D., senior research investigator and bariatric program manager at Penn Medicine and president of the Pennsylvania Academy of Nutrition and Dietetics.

The American College of Exercise (ACE) explains that protein helps repair microtears in muscle fibers caused by exercise. Damage and repair are what keeps and grows your muscle mass.

But protein isn’t just for athletes: According to the FDA, protein is required for the growth and repair of virtually all cells and body tissues, including skin, hair, and nails, bones, organs, and bodily fluids. That’s why it’s crucial to get enough of it during childhood and adolescence.

According to the FDA, protein aids in blood clotting, immune system response, vision, fluid balance, and the production of enzymes and hormones. It also contains calories, which can be stored or used by the body. (But this isn’t its main gig, which we’ll discuss later.)

What happens when you eat protein?

It’s not like you eat chicken and it goes straight to your biceps. Dietary protein is broken down and reassembled into the body’s proteins. Dr. Tewksbury explains that when you eat protein, your body’s first goal is to break it down into all the different amino acid units it was assembled from.

The liver then reconfigures the amino acids into the protein your body requires. Some proteins in the body help the immune system fight bacteria and viruses. Others aid in DNA synthesis, chemical reactions, or molecule transport, according to the NIGMS.

Because your body can not store excess protein, it will break it down and store it in fat tissue (as triglycerides), according to Merck Manuals. Whitney Linsenmeyer, Ph.D., R.D., nutrition and dietetics instructor at the Doisy College of Health Sciences at Saint Louis University and spokesperson for the Academy of Nutrition and Dietetics, tells SELF that broken-down protein can be converted into glucose and used as emergency fuel in rare cases. However, the body prefers carbs as its primary energy source (followed by dietary fat, if the body is not getting enough carbs). However, it is not ideal, according to Dr. Linsenmeyer. “Ideally, [our bodies] want to build and maintain body tissues.”

Exactly how much protein your body requires

So how much protein is this? According to the U.S. National Library of Medicine, the amount of protein your body needs for tissue growth and repair is determined by sex, age, height, weight, health, activity level, and overall calorie need. As a result, it will vary greatly between individuals.

The recommended daily allowance (RDA) for protein is a good starting point for estimating the minimum protein needs for most healthy individuals (who are sedentary or minimally active). The Protein RDA is 0.8 grams per kilogram of body weight per day or 0.36 grams per pound. For your RDA, multiply your body weight in pounds by 0.36. For example, the RDA for a 200-pound person is 72 grams of protein per day.

More active people will likely require more fluids. Adam M. Gonzalez, Ph.D., C.S.C.S., assistant professor in the Department of Health Professions at Hofstra University, that people who work out and want to maintain or build muscle mass benefit from eating more protein than the RDA.

How much more depends on how much you exercise and your body composition goals, as well as who you ask. The Academy of Nutrition and Dietetics (Academy), Dietitians of Canada (DC), and the American College of Sports Medicine (ACSM) reviewed the research on sports nutrition and agreed that the optimal daily protein intake for active adults and athletes is 1.2 to 2 grams per kilogram of body weight (or 0.5 to 0.9 grams of protein per pound). Most people who exercise should consume 1.4 to 2 grams of protein per kilogram of body weight (0.6 to 0.9 grams per pound) as recommended by the International Society of Sports Nutrition (ISSN).

According to those guidelines, a 200-pound person should consume 100 to 180 grams of protein per day. Dr. Gonzalez says that the more active you are—the more frequent, strenuous, and long your workouts—the higher you will be in that range.

How to space your protein intake

As important as the amount of protein you consume is when you eat it! It’s not just about eating a lot after a workout or at one meal and then skipping the rest of the day’s calories. The body doesn’t have a protein holding tank as it does for carbs, so we can’t store extras for later use.

That’s why it’s best to get your protein in small doses over the course of the day. In addition to keeping you satisfied and energized, eating a good amount of protein throughout the day helps your body direct protein where it’s needed. So look at your daily amount (above) and see how you can spread it out throughout the day.

Protein pacing is also critical for athletes. Dr. Linsenmeyer explains that adequate protein intake at breakfast, lunch, and dinner promotes muscle repair and growth. After a workout, protein is crucial, according to the Academy of Nutrition and Dietetics’ national media spokesperson, Yasi Ansari, M.S., R.D., C.SSD. “But people must understand that more [all at once] is not always better.”

Dr. Gonzalez says your muscles will crave protein for at least 24 hours after working out—most of the time if you exercise regularly. To maximize muscle repair, the Academy/DC/ACSM recommends 15 to 25 grams of protein every three to five hours. Getting 20 to 40 grams (or 0.25 grams per kilogram body weight) every three hours is recommended. As SELF explains, a good target is 20 to 30 grams of protein at a time. To be more precise, convert your body weight in pounds to kilograms (2.2) and multiply by 0.25 or 0.3. So, for a 200-pound person, that’s 23 to 27 grams of protein.

When your muscles need immediate repair, you want a similar amount. Ansari explains that lifting weights for an hour makes your muscles thirstier for protein than a 30-minute cardio workout. Most experts agree that a protein hit (15 to 25 grams per kilogram of body weight) within two hours of exercise maximizes muscle repair, while the ISSN recommends 20 to 40 grams (or 0.25 grams per kilogram of body weight).

In short, how much protein should you consume (A Day’s Protein Necessity)? This nutrient is essential to our bodies, so get the recommended amount no matter what. Get a bit more if you work out. Spread your protein intake throughout the day rather than at one meal.