Protein: Are You Getting Enough?

Medically Reviewed by Poonam Sachdev on December 17, 2023
8 min read

You might think that protein is just something you eat. But proteins are the basic building blocks of life. You have them in every cell of your body. Protein is the most plentiful substance in your body after water.

You need protein to grow your muscles, bones, skin, and hair, but also to make up the enzymes that power chemical reactions in your cells, the antibodies that help you fight off infections, and the hormones that send messages from one part of your body to another.

Proteins are made up of smaller parts called amino acids. Foods with protein can contain 20 types of amino acids. Nine of those amino acids are considered essential, meaning our bodies can't make them on their own. Our bodies use all 20 amino acids, in different combinations, to make the proteins we need. 

The proteins in your body are constantly repaired and replaced. That means you need to keep eating foods with protein, containing essential amino acids, to keep your body working as it should. 

Protein is especially crucial when the body is growing or has extra work to do, such as during childhood, teen years, pregnancy, and breastfeeding. 

Like fats and carbohydrates, protein can give you energy. But that's not its main job. Protein has some special roles. Here are just a few of things protein does for you:

It helps your body maintain a proper fluid balance. Having enough protein in your blood helps keep enough water in your blood.

It builds and repairs tissues. This is especially important at times of growth, when you are sick, or when you are recovering from an injury. It's also important as you age, because getting enough protein can help prevent loss of bone and muscle.

It clots your blood. When you get a cut, protein fibers quickly form to plug the cut and stop the bleeding.

It keeps many body systems working. The hemoglobin in your blood that carries oxygen through your body is mostly made of protein. Insulin, the hormone that regulates your blood sugar, is a protein, too.

Eating the right amount of protein might have other benefits, including:

Making you feel full so it's easier to lose weight

Repairing muscles after exercise



About a billion people in the world don't get enough protein in their diets. In some countries, up to a third of children are short on protein and at risk for poor growth and other problems. Most people in the United States, including children, get more than enough. Older adults are less likely, though, to get as much as health groups recommend. 

Older adults who don't get enough protein are more likely to be frail, meaning they are weak, move slowly, feel exhausted, and may lose weight unintentionally. Frailty increases the risk of getting hurt or sick. 

Children with extremely low protein intakes can develop a condition called kwashiorkor. That's a form of malnutrition that can stunt growth. The most recognizable symptom is a bloated belly. It also can cause hair loss, dry, peeling skin, crankiness, and tiredness. The condition is rare in rich countries. 


We all need protein, but we don't need the same amount. Our needs vary, depending on age, weight, and other factors. For example, you need more if you are pregnant or breastfeeding, and people assigned male at birth generally need more than those assigned female. People who are sick, injured, or recovering from surgery may need extra. Some health groups recommend extra protein for athletes.

Most people in the United States get at least as much protein as recommended by the National Academy of Medicine, the group that sets Recommended Dietary Allowances (RDAs) used in government guidelines. Young and middle-aged men are especially unlikely to be low on protein. At ages 19 to 59, many get more than recommended, often from diets heavy on meat, poultry, and eggs. 

Protein requirements by age: 

The National Academy of Medicine recommends that adults get about 0.8 grams of protein a day for every kilogram they weigh. That's about 7 grams for every 20 pounds. It suggests babies and children get a bit more, ranging from 1.2 grams per kilogram for infants to 0.85 grams per kilogram for teens. (To find your weight in kilograms, divide your weight in pounds by 2.2046. Then, multiply that number by 0.8 to figure out how many grams of protein you need as an adult.) Under the guidelines, a 150-pound adult would need about 54 grams of protein per day.

The guidelines mean that, on average: 

  • Babies need about 10 grams a day.
  • School-age kids need 19-34 grams a day.
  • Teens assigned male at birth need up to 52 grams a day.
  • Teens assigned female at birth need 46 grams a day.
  • Adults assigned male at birth need about 56 grams a day.
  • Adults assigned female at birth need about 46 grams a day (71 grams if pregnant or breastfeeding).

To put those amounts in perspective, consider that you get about 7 grams of protein in an ounce of nuts, 8 grams in a cup of milk or a half-cup of cooked beans, and about 20 grams in a 3-ounce portion of chicken or salmon.

You should get at least 10% of your daily calories, but not more than 35%, from protein, according to the academy. So if you eat 2,000 calories a day, 200 to 700 calories should come from protein.

Aging and protein

As we age, getting enough protein becomes more important. That's because we lose muscle naturally, starting in our 30s and speeding up each decade after that. This loss of muscle and strength is called sarcopenia. Eventually, this can increase your risk of frailty, falls, and broken bones and make it harder for you to live on your own. Eating enough protein is one way to slow down muscle loss. It also can keep your bones stronger.

Many aging experts recommend that people over age 65 aim for the high end of recommended daily protein intake, meaning you get up to 35% of your daily calories from protein. 

Pregnancy, breastfeeding, and protein

During pregnancy, you need extra protein to support all the changes in your body and to help your baby grow. Protein is especially important after the first one-third of pregnancy, when the baby grows the most and your body does a lot of extra work. Research suggests about 1 in 8 pregnant women in the United States don't get enough protein during the final two-thirds of pregnancy.

If you breastfeed, you need to keep eating extra calories and protein to keep yourself healthy and nourish your baby. 

Athletes and protein

While the national academy says there's not enough evidence to recommend extra protein for people who do a lot of exercise, some health groups do recommend more for active people. People who run, swim, cycle, or do other endurance sports should aim for 1.2 to 1.4 grams of daily protein for every kilogram they weigh, according to the American College of Sports Medicine, the American Dietetic Association, and Dieticians of Canada. If you lift weights or do other kinds of strength training, the groups recommend 1.2 to 1.7 grams of daily protein for every kilogram you weigh. 

Getting enough protein helps your body recover from exercise and build stronger muscles, the groups say.

You can get too much protein. People who follow diets that are very high in protein or use lots of protein supplements can get into health trouble.

Among the possible effects:

Kidney damage: Too much protein makes your kidneys work harder. If you already have kidney problems, you are at especially high risk. If you have foamy urine, that's a sign that there's too much protein in your urine and you should talk to your doctor right away.

Dehydration: When your kidneys work too hard to deal with extra protein, your body might run low on fluids, causing symptoms like dry mouth, dry skin, and thirst.

Tummy trouble: Too much protein, especially in the form of red meat, can be hard on your digestive system, leading to symptoms such as constipation, diarrhea, and bloating. 

Weight problems: If you are trying to maintain your weight or lose pounds, adding extra calories from protein will work against you if you don't cut calories elsewhere.

Bad breath: Diets high in protein and low in carbohydrates can cause ketosis, which means your body burns fat for energy. Bad breath is a side effect of ketosis. But most ketogenic diets – used as a treatment for some health problems and for weight loss – are much higher in fat than protein.

If your high-protein diet is heavy on red meat, processed meats, and saturated fat, you may also raise your level of unhealthy cholesterol and your risk of heart disease


Just about every type of food has protein. Some foods have more than others. Whether you eat meat or not, you can get enough protein from your diet.

But where you get your protein can make a big difference in your health. Foods that are high in protein that can be part of a healthful diet include:

  • Lean meats such as chicken, turkey, beef, and pork 
  • Fish like salmon, tuna, mackerel, anchovies, and trout 
  • Dairy products like milk, cheese, and yogurt 
  • Beans, peas, and lentils 
  • Nuts and seeds, such as almonds, walnuts, peanuts, chia seeds and sunflower seeds. Nut butters count, too. 
  • Eggs 
  • Quinoa, an edible seed considered a whole grain
  • Soy products such as tofu and tempeh

When you choose from that list, it's important to consider not only your taste preferences, but what you might be getting along with all that protein. The best choices for you depend on your health needs and goals. For example:

To limit saturated fat, you can choose lean cuts of meat over fattier cuts.

To cut back on sodium, you should skip processed meats like hot dogs and sausage.

To get more omega-3s, you might choose salmon, tuna, walnuts, or eggs fortified with omega-3s.

To get more fiber, look to beans, nuts, legumes, and high-protein vegetables like broccoli and Brussels sprouts.

To lower heart disease risk, limit the amount of red meat you eat, especially processed red meat, and eat more fish, poultry, and beans.

If you're watching your weight, try including protein with every meal. It will help you feel full longer. 

If you are a vegan, a a vegetarian, or eat mostly plant foods, get your protein from a variety of plant sources to get all the amino acids you need. Mix and match legumes, nuts and seeds, whole grains, fruits, and vegetables. Vegans – who eat no animal products – might fall short on some amino acids if they don't eat a wide enough variety. Supplements can fill the gap. But research suggests most vegans don't need them.

Protein is an important part of a healthy diet. Most of us get enough, but you may need extra if you are still growing, are pregnant or nursing, are very active, or if you are over age 65. To get the most health benefits, try to choose a variety of high-protein foods.