Protein comes from a wide range of foods, both animal and plant-based. Meat, fish, eggs, and dairy are the most concentrated sources, but legumes, nuts, seeds, and soy products can supply plenty of protein too. Most adults need about 0.8 grams of protein per kilogram of body weight daily at minimum, which works out to roughly 55 grams for a 150-pound person. If you’re physically active, that number climbs to 1.0 to 1.6 grams per kilogram depending on intensity.
Meat, Fish, Eggs, and Dairy
Animal foods pack the most protein per serving and contain all nine essential amino acids your body can’t make on its own. A palm-sized portion of chicken breast (about 3 ounces) delivers around 26 grams. The same amount of beef or salmon provides roughly 22 to 25 grams. A single large egg has about 6 grams, and a cup of Greek yogurt typically contains 15 to 20 grams.
Dairy products like cottage cheese, regular yogurt, and milk are reliable sources too. Cottage cheese is especially dense, with about 14 grams in a half-cup serving. Cheese varies widely: harder cheeses like parmesan have more protein per ounce than softer ones like brie.
Plant-Based Protein Sources
Plants can absolutely supply enough protein, though most individual plant foods don’t contain all nine essential amino acids in ideal proportions. The exceptions are whole soy foods like tofu, tempeh, edamame, and miso, which are complete proteins. Tempeh is particularly impressive at 20 grams per three-quarter cup, and seitan (made from wheat gluten) delivers 18 grams in a 3-ounce serving.
Lentils provide about 10.5 grams per half cup cooked. Tofu comes in around 7 grams per 3 ounces. Pumpkin seeds offer 8.5 grams per ounce, making them one of the higher-protein snacks you can grab. Chickpeas, black beans, and other legumes fall in a similar range to lentils.
If you eat a variety of legumes, grains, nuts, and seeds throughout the day, you’ll get all the amino acids you need without carefully combining foods at every meal. Classic pairings like rice and beans or hummus and pita do complement each other, but your body pools amino acids over the course of a day rather than requiring a perfect combination at each sitting.
Not All Protein Is Absorbed Equally
Your body doesn’t extract the same amount of usable protein from every food. Scientists measure this using a digestibility score that accounts for amino acid quality and how well your gut absorbs them. Soy scores around 91 out of 100, close to animal proteins. Peas score about 70, and wheat comes in at roughly 48. This doesn’t mean wheat is useless for protein, but it does mean you’d need to eat more of it (or pair it with other sources) to get the same benefit.
In practical terms, if you eat mostly plant-based, aiming slightly higher than the minimum protein recommendation helps compensate for lower digestibility. Soy-based foods are the clear standout among plant proteins for quality.
How Much You Actually Need
The baseline recommendation of 0.8 grams per kilogram of body weight per day is designed for sedentary adults and represents the minimum to avoid deficiency, not necessarily the optimal amount. For moderate physical activity, 1.3 grams per kilogram is a better target. For intense exercise or strength training, research supports up to 1.6 grams per kilogram.
The average American already eats about 1.2 to 1.4 grams per kilogram daily, which is above the minimum but within the normal range. For a 150-pound person, that translates to roughly 80 to 95 grams of protein a day.
Getting Protein on a Budget
Some of the cheapest protein sources are also the most effective. Eggs, canned tuna, chicken breast, and dried beans consistently rank as the best value per gram of protein. A dozen eggs costs a few dollars and delivers about 72 grams of protein total. Dried black beans and lentils are even cheaper per serving and store for months in your pantry.
Unflavored protein powder (whey or a pea-rice blend) is another cost-effective option if you just want to boost the protein content of meals you’re already making. You can stir it into oatmeal, smoothies, or soups without significantly changing the flavor.
What Protein Does in Your Body
Protein isn’t just about muscle. Your body uses it to build antibodies that fight infections, produce enzymes that drive virtually every chemical reaction in your cells, and create hemoglobin that carries oxygen in your blood. It forms the structural framework of your bones, skin, and connective tissue. Hormones and signaling molecules that let your cells communicate with each other are built from protein too.
When you eat protein, your digestive system breaks it into individual amino acids, which your body then reassembles into whatever it needs. There are 20 amino acids total, and nine of them are “essential,” meaning you have to get them from food because your body can’t manufacture them.
Signs You’re Not Getting Enough
True protein deficiency is uncommon in developed countries, but it does happen, especially in people with very restrictive diets, eating disorders, or certain medical conditions. The signs tend to build gradually. Muscle loss is one of the earliest, because your body breaks down muscle tissue to free up amino acids for more critical functions like keeping your heart and immune system running.
Other signs include hair that becomes brittle or falls out faster than normal, dry or pale skin, swelling in the hands and legs (caused by low levels of a blood protein called albumin), frequent infections, slow wound healing, and unexplained fatigue. In severe cases, particularly in people with anorexia, the body can even break down heart muscle, which is one of the most dangerous consequences of prolonged protein starvation.
Weight changes can go in either direction. Some people lose weight from overall calorie and protein restriction. Others actually gain weight over time because muscle loss slows metabolism, so the same number of calories that once maintained their weight now produces a surplus.
Can You Eat Too Much?
For people with healthy kidneys, there’s no strong evidence that high protein intake causes kidney damage. Large observational studies have found that increased protein didn’t affect kidney function in people with normal renal health. The concern is real, however, for people who already have reduced kidney function or only one kidney. In those cases, keeping intake below 1.2 grams per kilogram and watching sodium is generally advised.
Intakes above 1.5 grams per kilogram per day are generally considered “high protein.” Most people eating a standard diet land well below that threshold without trying. If you’re deliberately eating high-protein for athletic or weight-loss goals, staying hydrated and getting adequate fiber helps your kidneys and digestive system handle the extra load.