When it comes to basic nutrition, there’s arguably no more important building block than protein. Protein, most people know, is essential for repairing and rebuilding muscle tissue, but it also serves other crucial purposes. You need protein to make organs and skin. You need protein to produce hair, blood, and connective tissue. Protein produces enzymes and neurotransmitters. It also keeps your immune system in top shape.
Protein itself is made up of smaller molecules known as amino acids. To function properly, the body needs 20 different amino acids. The irony is that while the body makes hundreds of amino acids in the course of a day, it’s unable to make nine of the so-called essential amino acids. We get those amino acids from foods, and they have big jobs. Isoleucine, for instance, aids in the production of hemoglobin, while leucine is the amino acid that helps grow and repair muscle tissue.
“That’s the key important feature,” says registered dietitian Wesley McWhorter. “Especially in regard to overconsumption of protein or eating too little.”
Here comes the inevitable question: How much protein do we really need? It actually isn’t all that complicated, although the rules, so to speak, change if you’re an athlete or someone who spends hours at the gym.
Keep It 100
McWhorter says the general guideline is 0.35 grams of protein for every pound of body weight. So someone who’s 200 pounds needs to eat about 70 grams of protein per day. Most people will not have to work at this: Americans typically consume around 100 grams of protein each day.
But this can be easier or harder depending on your usual diet. Meat and fish are good sources of essential amino acids. Beef, chicken, turkey, salmon—all can be the backbones of a protein-rich diet. A 3-ounce serving of salmon contains 19 grams of protein. The same serving of skinless chicken breast contains 27 grams of protein.
But it's possible to get enough protein on all kinds of diets. Johns Hopkins has a good breakdown of protein-packed foods. You’ll notice that many foods make the cut: Black beans, lentils, peanut butter, eggs, cow’s milk, and soy milk are all rich in protein.
You Might Need More
For athletes and guys who spend hours at the gym, a bigger helping of protein is recommended. One gram of protein per pound of body weight is about right—and extremely easy to remember. “Going above [the usual number] is because of the ‘cannibalism’ that happens when you’re exercising hard,” says McWhorter. “When you’re breaking down muscle, you need to build it back up.”
Getting this much protein can be more of a challenge. Shakes and supplements can be helpful but, as usual, whole foods are generally better. (Many of the amino acids from a shake or other similar sources can be simply secreted in the urine.)
Also keep in mind that protein doesn't do much without the workout beforehand. “If you’re the average guy who’s not exercising a lot, if you sit on the couch and drink a protein shake, you’re not going to have bulging biceps,” McWhorter says.
Don’t Eat Too Much
Just because protein is good for your nutrition doesn’t mean you should necessarily overload your plate. When you’re eating a high-protein diet, you should think about what else is—or isn’t—in your diet. Vegetables and other high-fiber foods should also be a part of your meals. You won’t get that if you’re eating a baked potato and a tomahawk steak (no matter how delicious that is on its own).
Another important factor is how much the body can effectively use. Our bodies have an endless capacity for holding onto fat, but they don’t store protein. It’s being used constantly throughout the day. But eating more protein than you need—a hallmark of the keto diet—will lead to that protein being converted into glucose for energy, or worse.
“If you don’t spread out your protein intake, your body’s not going to use it all. So your body is going to store it as fat,” says McWhorter.
It’s much better to spread out your protein throughout the day, frequently eating some protein over the course of different meals, especially if you’re working out a lot and need to keep repairing muscle. Some eggs in the morning, a piece of fish at lunch, and a dinner plate with, say, chicken, broccoli, and rice is the way to go.