Foods You Should Eat If You Need More Protein

Although we tend to think of protein as a single thing, it's actually a term for a vast array of molecules made up of smaller components called amino acids (via The Conversation). The human body contains 20,000 or more unique proteins. These proteins do everything from providing structure to cells and tissues to spurring biochemical reactions to powering the immune system. But you gotta eat proteins to make proteins. When we eat dietary protein, the body breaks it down into its constituent amino acids. The body then recombines these amino acids in new ways to form the thousands of proteins it needs to function properly.

The body isn't able to store extra protein in the same way it can store extra carbohydrates or fat for later use. This means it's important to consume enough dietary protein on a daily basis to make sure your body has the raw materials to make the proteins it needs (via SF Gate). When most people think of high-protein foods, they think of meat. It's true that meat is an excellent source of protein, but there are many plant-based sources as well. However, as a 2004 paper published in the Journal of Sports Science & Medicine pointed out, not all dietary proteins are created equal in terms of amino acid content and digestibility. 

So which high-protein foods should you be eating? How much protein do you actually need? And what exactly is your body doing with all that protein you eat?

Edamame

Edamame are immature soybeans, and they're the poster child for plant-based protein. A one-cup serving of cooked edamame contains an impressive 18.5 grams or protein. But what makes edamame and other soy products particularly special is that they're one of only a handful of plant-based foods that serve as a complete protein source (via Healthline).

What's a complete source or protein? As the National Institutes of Health (NIH) explained, all proteins are made up of some combination of 20 different amino acids. Nine of these (phenylalanine, valine, tryptophan, threonine, isoleucine, methionine, histidine, leucine, and lysine) are considered essential because our bodies can't produce them and must get them from food. On the other hand, if it's not getting enough of the 11 nonessential amino acids from food, our bodies can manufacture these by modifying essential amino acids. Some nonessential amino acids, however, including arginine and histidine, are considered "conditionally essential." This means that during certain periods of increased demand (such as during pregnancy or when recovering from an injury), the body can't make sufficient quantities of these amino acids itself and must get at least some of what it needs from food. 

Any food that contains all nine essential amino acids in appropriate quantities is considered a complete protein. All animal products are complete proteins, but almost all plant foods are incomplete proteins, meaning they don't offer all the essential amino acids. But eating a variety of incomplete proteins ensures you get all the essential amino acids.

Eggs

If you're looking to up your protein intake, eggs are a fantastic option. And while egg whites get all the credit when it comes to protein, there's no need to skip the yolk. In fact, according to Science Direct, 50% of the protein is in the white, 40% is in the yolk, and the remaining 10% is in the shell and membrane lining the shell (which even die-hard egg fanatics probably aren't eating). A single whole egg contains 6 to 8 grams of protein and includes all the essential amino acids in the proper proportion (via the Cleveland Clinic).

When it comes to protein quality, there's more to consider than just complete versus incomplete proteins. Digestibility also matters. According to a 2000 paper published in The Journal of Nutrition, the digestibility of a protein represents how efficiently our bodies can actually absorb and use protein from a particular source. Eggs and beef top the list, each with a digestibility score of 98%. Cow's milk and soy come in a bit lower at 95%. The protein in wheat, however, only has a digestibility score of 91%, and other plant sources, such as beans, have even lower values. What does this mean in the real world? If you tend to eat proteins that are less easily digested, you may not be getting as much protein as the Nutrition Facts panel suggests — and you may need to increase your intake or switch to proteins with better digestibility, such as eggs.

Beef jerky

Beef is a fantastic source of protein, and when that beef is dehydrated, the protein content becomes even more concentrated on an ounce-for-ounce basis. According to Healthline, a tiny one-ounce serving of beef jerky contains a hefty 9.4 grams of protein. By comparison, an ounce of cooked beef contains 7 grams of protein (via Taste of Home).

But just how much protein should you be aiming to eat each day? A recommended dietary allowance (RDA) for protein has been set by the U.S. government and is expressed as a formula: 0.8 grams per kilogram of body weight. But as registered dietitian Nancy Rodriguez explained in an interview with Harvard Medical School, she and many other health professionals believe that getting up to twice the RDA is a "safe and good range to aim for." To complicate matters, the Nutrition Facts panel on food packaging uses a set daily value (DV) for protein when calculating what percent of your needs a serving of a particular food provides. The DV for protein is just 50 grams (via the Food and Drug Administration). Based on the RDA formula, this would only be sufficient for a sedentary 139-pound individual. For anyone heavier or more active than that, the DV won't be enough to meet even the RDA, let alone Rodriguez's suggestion for optimal health.

Lentils

If you're looking for more meatless protein sources, lentils are a great option. They're more than 25% protein, and although the exact amount will vary between varieties, you can expect to get about 17.9 grams of protein from one cup of cooked lentils. One thing to note, however, is that lentils contain trypsin inhibitors, substances that block the production of the enzyme trypsin, which helps break down dietary proteins. But research suggests that lentils contain such small amounts of these enzyme blockers that they won't have any noticeable effect on your ability to digest the protein you eat (via Healthline).

According to surveys conducted by the U.S. government, most Americans get plenty of protein. There are, however, some groups at increased risk of not getting enough protein (per UC Davis). While it's totally possible to get enough protein on a vegetarian or vegan diet, the relatively few plant-based sources of complete protein mean that people who don't eat animal products need to pay attention to the plant proteins they eat so that they get the full range of essential amino acids. Individuals with medical conditions that impair absorption of nutrients are also at increased risk for protein inadequacy. People experiencing a period of rapid physiological change (pregnant women or growing infants, for example) have increased protein needs, which means it may be easier to fall behind. As we age, are bodies become less efficient at synthesizing proteins, so we may need more dietary protein to get the job done.

Spirulina

Spirulina is a type of blue-green algae, and is considered one of the oldest lifeforms on Earth. Hundreds of years ago, it was used by the Aztecs as an endurance-booster and disease-fighter. Today, it's risen to superfood stardom, mixed into yogurt and smoothies or taken in capsule form. Its stellar nutritional profile includes an impressive 4 grams of protein in just one tablespoon (via WebMD).

Protein is critical to good health, but can you get too much of a good thing? According to the Mayo Clinic, the answer is yes. Breaking down dietary protein can be taxing for the kidneys, so a very high-protein diet could be dangerous for those predisposed to or who already have kidney disease. And because many forms of dietary protein come bundled with hefty amounts of saturated fat (think meat), eating a lot of these foods may increase your risk for high cholesterol and heart disease. What's more, because the body can't store excess protein for later use, any extra dietary protein that isn't used to make body proteins or burned for energy will be converted to fat and stored.

Experts don't agree on how much protein is "too much" (and it's likely a highly individualized number), but a 2016 paper published in Food & Function suggested an upper limit of 2 grams per kilogram of body weight for most adults or as much as 3.5 grams per kilogram of body weight for individuals well-adapted to a high-protein diet.

Oatmeal

Looking for a protein-packed breakfast but don't have time to cook a big plate of steak and eggs? Oatmeal's got you covered. A 3.5-ounce serving of oats contains 16.9 grams of protein (via NutritionData). And according to a 2012 paper published in Critical Reviews in Food Science and Nutrition, "oats ... are distinct among cereals due to their considerably higher protein concentration. At the same time oats possess a protein quality of high nutritional value and a special protein composition." The majority of the proteins found in oats are from the globulin family, which are more bioavailable than the prolamin group of proteins found in large amounts in other grains. In fact, the protein makeup of oats resembles that of legumes.

Everyone knows you need to eat adequate protein to build strong muscles, but does when you eat that protein matter? As a 2013 paper published in the Journal of the International Society of Sports Nutrition explained, protein timing is a popular health hack claiming that to optimize muscle recovery and growth after exercise, you need to eat adequate amounts of protein within a narrow "anabolic window" surrounding that exercise. After analyzing a number of previously published studies, the paper's authors concluded that when protein was consumed relative to exercise had no significant impact on muscle growth. Getting enough protein overall, however, was correlated to increased muscle mass. So go ahead and eat that oatmeal whenever you feel like it.

Peanuts

If you need a quick protein hit, pop a handful of peanuts. A one-ounce serving has 6.9 grams of the stuff. Don't like or are allergic to peanuts? There are many other high-protein nuts to choose from. (And hey, peanuts are technically a legume anyway!) The same size serving of almonds or pistachios offers 6 grams, while cashews or walnuts provide 4.3 grams. You'll get 3.9 grams of protein in an ounce of pine nuts and 2.6 grams in an ounce of pecans (via MyFoodData).

Without protein, you'd be an amorphous blob. There are more than 100 types proteins in the human body that give us structure and support. The most abundant of these is collagen, which makes up 6% of total body weight. Collagen makes up 30% of our bones and is found in large amounts in muscles, ligaments, tendons, cartilage, and skin. While collagen provides strength and stability, another structural protein called elastin provides stretch and flexibility. Although most people think about the synergy of collagen and elastin when they think about skin health, this dynamic duo is important throughout the body. For example, thanks to collagen and elastin, blood vessels have the strength and suppleness they need to function. Keratin is another sturdy structural protein, and is found in hair, nails, and skin (via Penn State).

Tuna

Tuna is an excellent source of protein, though the exact amount you'll get depends on what type you choose. Three ounces of cooked yellowfin tuna, for instance, contains 26 grams of protein. The same serving size of canned light tuna in oil has about 25 grams of protein, while canned tuna in water has only about 20 grams (via SF Gate).

Although most people focus on protein's ability to build bigger muscles, that's just the tip of the iceberg when it comes to the value of protein. In fact, without protein, your body wouldn't be able to do ... well, basically anything. That's because the protein we eat is used to make enzymes. As Penn State explained, "enzymes are proteins that conduct specific chemical reactions. An enzyme's job is to provide a site for a chemical reaction and to lower the amount of energy and time it takes for that chemical reaction to happen." 

And your body needs to orchestrate a mind-blowingly large number of chemical reactions to keep you alive. In fact, every second, there are more than 100 reactions going on simultaneously in every cell of the body. Luckily, enzymes can catalyze reactions over and over again before eventually being destroyed and rebuilt. If that wasn't the case, there wouldn't be enough hours in the day to eat all the protein you'd need to make enzymes.

Quinoa

Although technically a seed, quinoa is considered a whole grain. You'll get 8 grams of protein in every cup of cooked quinoa (as well as lots of fiber and important micronutrients). Like soy, quinoa is relatively rare among plant foods because it's a complete protein source (via the Harvard School of Public Health).

Proteins and the amino acids that comprise them are necessary for creating hormones. As Penn State explained, "hormones are the chemical messengers produced by the endocrine glands. When an endocrine gland is stimulated, it releases a hormone. The hormone is then transported in the blood to its target cell, where it communicates a message to initiate a specific reaction or cellular process." 

Hormones can be divided into three broad groups based on the molecules they're constructed from (via Lumen Learning). While lipid-derived hormones such as testosterone and estrogen are built from fatty acids, the other two classes of hormones are built from proteins. Amino acid-derived hormones are relatively small molecules built around the amino acids tyrosine and tryptophan. These hormones include melatonin (which regulates sleep), epinephrine and norepinephrine ("fight or flight" hormones produced by the adrenal glands), and thyroxine (produced by the thyroid gland). Peptide hormones are made of much longer chains of amino acids. Peptide hormones include insulin (which drives glucose into the cells and controls blood sugar levels), oxytocin (the "love hormone"), and human growth hormone.

Chicken

Ever wonder why chicken noodle soup is the quintessential immune-boosting meal for when you're feeling under the weather? It's largely thanks to chicken's high protein content. According to Healthline, 3.5 ounces of chicken breast contains 31 grams of protein, while an equal-size portion of wing meat provides 30.5 grams, drumsticks 28.3 grams, and thighs 26 grams.

The immune system's ability to find and destroy foreign invaders relies on the production of a variety of enzymes and antibodies, both of which are proteins (via Penn State). But certain amino acids may be more important for the immune system than others. In a study published in Critical Care Medicine, the authors explained that the amino acid arginine "was demonstrated to enhance cellular immune mechanisms, in particular T-cell function." The researchers also noted that arginine helps preserve the immune system when it's weakened by low overall protein intake. 

Glutamine is another amino acid critical for immune function. A 2018 paper published in the journal Nutrients found that glutamine was essential for lymphocyte proliferation. This is the process by which lymphocytes, a type of immune cell, "remember" specific pathogens so that they can defeat them again in the future. Macrophages also need glutamine to secrete their germ-killing substances and "eat" invading or damaged cells. Glutamine is also used by natural killer cells when they attack bacteria.

Beans

Beans, beans, the magical fruit. The more you eat, the more ... protein you get. A one-cup serving of cooked pinto beans contains 15.4 grams of protein, and other bean varieties aren't fare behind. The same serving size of kidney beans offers 15.3 grams, black beans 15.2 grams, navy beans 15 grams, and lima beans 14.7 grams (via MyFoodData).

The body uses amino acids from dietary protein to make two critically important carrier proteins: hemoglobin and myoglobin. Hemoglobin is a protein found at the center of red blood cells. It picks up oxygen from the lungs and delivers it to every cell in the body as red blood cells travel through arteries. Cells need this oxygen to produce energy and function properly. Then, as the red blood cells travel through the veins, hemoglobin binds to carbon dioxide and helps bring this waste product to the lungs, where it's exhaled (via PubMed Central). 

Myoglobin is similar to hemoglobin in that it helps transport oxygen, but it's found only in muscle tissue. It delivers oxygen to muscle cells, particularly when they're being strained (during exercise, for example). Myoglobin also helps break down nitric oxide, a waste product that builds up in muscle cells. Myoglobin is found in skeletal (regular) muscles, cardiac (heart) muscle, and, to a lesser degree, the smooth muscle that lines your gastrointestinal tract (per StatPearls).

Nutritional yeast

Using nutritional yeast is an easy way to sneak more protein into your diet, especially if you're a vegetarian or vegan. This cheesy-tasting powdered and deactivated yeast can be used in a myriad of ways, including sprinkled on salads or stirred into soups. Per Verywell Fit, you'll get a respectable 8 grams of protein in just 1.5 tablespoons of the stuff. Nutritional yeast is also a complete protein.

Because of the tens of thousands of proteins the body must produce in order to function properly, the vast majority of the dietary protein we eat is used to make bodily proteins. But just like fats and carbohydrates, dietary protein can also be broken down and used for energy, though it's not the body's preferred fuel source. In a balanced diet, only about 10% of the protein we eat is burned as energy — the other 90% is used to make bodily proteins. If a person isn't eating enough fats or carbs, however, more protein may need to be burned for energy to keep the body running, which can hinder the synthesis of bodily proteins (via Penn State). 

When used for energy, a gram of protein yields four calories (via the USDA). At least in theory. In reality, it takes quite a bit of energy to break down dietary protein, which diminishes the net gain. As a 2014 paper published in Nutrition & Metabolism explained, about 15%–30% of the total calories in protein are "lost" during digestion.

Yogurt

Yogurt can be a great way to get more protein in your diet, but make sure you're picking the right type to get the most bang for your buck. As Healthline explained, 8 ounces of regular low-fat yogurt contains a respectable 13 grams of protein, while the same portion size of low-fat Greek yogurt packs in a whopping 24 grams. Greek yogurt is made by straining out the liquid, making Greek yogurt much denser, so you get more protein with each bite.

Eating high-protein yogurt for breakfast could help stave off the pre-lunch munchies. In a 2003 study published in Appetite, participants consumed 160 calories of either low-protein (5 grams), moderate-protein (14 grams), or high-protein (24 grams) yogurt for three days. Researchers tracked participants' subjective feelings of fullness and how much they ate after consuming the yogurt. Those who consumed the high-protein yogurt reported feeling fuller than those who ate the low- or moderate-protein yogurts. The high-protein group also ate dinner 26 minutes later than the low-protein group. 

Those results aren't surprising. According to the Cooper Institute, how full (satiated) you feel after eating something depends on the macronutrient content of that meal. While food that takes up a lot of space in your stomach may trigger signals to stop eating, protein, along with fiber, has the biggest role to play in controlling when you'll be hungry again.

Milk

Milk does a body good for more reasons than its calcium content. It's also a solid source of protein. The lower the fat percentage, the higher the protein content (although the difference isn't substantial, so opt for the type you like best). A 3.5-ounce serving of nonfat milk contains 3.4 grams of protein, while the same amount of 1% milk offers 3.37 grams and whole milk provides 3.15 grams (via SF Gate). There are two proteins in milk: casein (accounting for about 80% of total milk protein) and whey (which makes up the remaining 20%). Both are complete proteins and have high digestibility. In fact, these proteins are often isolated and used as the basis for protein powders and supplements (via Healthline).

But the protein in milk doesn't sit well with everyone. As the Mayo Clinic explained, people with a milk allergy — which is very different from lactose intolerance — have an abnormal reaction to one or both of the proteins in milk and other dairy products. Eating dairy triggers an immune response that can cause hives, swelling in and around the mouth, shortness of breath, gastrointestinal distress, and, in severe cases, anaphylaxis and even death. Per WebMD, nilk is one of the eight most common food allergies.

According to a 2004 paper published in Current Asthma and Allergy Reports, "food allergens are almost always proteins, but not all food proteins are allergens." Certain biochemical characteristics of some food proteins make them more or less likely to trigger allergic reactions.