Protein foods are any foods that supply a significant amount of protein, one of the three macronutrients your body needs in large quantities every day. Meat, poultry, fish, eggs, dairy, beans, lentils, nuts, seeds, and soy products all qualify. Your body uses the protein from these foods to build and repair muscle, make enzymes and hormones, support your immune system, and maintain skin, hair, and bone.
What Protein Does in Your Body
At least 10,000 different proteins keep your body running. Some form the physical structure of your muscles, bones, and skin. Others work as enzymes, powering the thousands of chemical reactions happening in your cells at any given moment. Hemoglobin, the molecule that carries oxygen through your blood, is a protein. Antibodies that fight off viruses and bacteria are proteins. Even many hormones that coordinate signals between your organs are proteins.
When you eat protein food, your digestive system breaks it down into smaller building blocks called amino acids. Your body then reassembles those amino acids into whatever proteins it needs. Nine of these amino acids are “essential,” meaning your body cannot produce them on its own. You have to get them from food.
Animal Protein Sources
Animal foods tend to be the most concentrated protein sources, and they’re almost always “complete” proteins, meaning they contain all nine essential amino acids in adequate amounts. The most common options include:
- Poultry: A 3-ounce cooked serving of chicken or turkey (roughly the size of a deck of cards) provides about 21 to 26 grams of protein.
- Beef and pork: A similar 3-ounce portion delivers 22 to 26 grams, depending on the cut.
- Fish and seafood: Salmon, tuna, shrimp, and other seafood typically provide 20 to 25 grams per 3-ounce serving, with the added benefit of omega-3 fatty acids in fatty fish.
- Eggs: One large egg contains about 6 grams of protein. Two or three eggs at breakfast gets you to 12 to 18 grams.
- Dairy: A cup of milk has about 8 grams, a cup of Greek yogurt around 15 to 20 grams, and an ounce of cheese (picture three or four dice) provides 6 to 7 grams.
Plant Protein Sources
Plant foods generally contain less protein per serving than animal foods, and most are “incomplete,” meaning they’re low in one or more essential amino acids. But this is easy to work around. You don’t need to combine specific foods at each meal. As long as you eat a variety of plant proteins throughout the day, your body gets all the amino acids it needs.
Some of the best plant protein sources, based on data from Johns Hopkins Medicine:
- Lentils: 9 grams per half cup cooked
- Hummus (chickpeas): 7 grams per third of a cup
- Quinoa: 6 grams per third of a cup cooked
- Nuts: 4 to 6 grams per ounce (about a small handful)
- Beans and peas: 7 to 9 grams per half cup cooked
A few plant foods stand out as complete proteins: soy products like tofu, edamame, and tempeh contain all nine essential amino acids. Quinoa and chia seeds are also complete. Soybeans score nearly as high as beef on protein quality scales that measure how well your body absorbs and uses the amino acids (0.91 versus 0.92 on a 0-to-1 scale).
Plant-Based Meat Alternatives
Newer plant-based meat products made from soy, pea protein, or other sources are similarly high in protein compared to animal meat. A recent review of analytical data on 45 nutrients found that plant-based meat and animal meat have comparable protein content and overall nutrient density. Plant-based versions tend to be lower in saturated fat and higher in fiber, while also providing more vitamin E, magnesium, calcium, and folate than animal meat. They do tend to be higher in sugar and carbohydrates.
How Much Protein You Need
The Recommended Dietary Allowance is 0.8 grams of protein per kilogram of body weight, or about 0.36 grams per pound. For a 140-pound person, that works out to roughly 53 grams per day. For a 180-pound person, it’s about 65 grams. This is the minimum to prevent deficiency in a sedentary adult, and it amounts to only about 10% of total daily calories.
If you’re trying to lose weight while preserving muscle, research supports eating more than the baseline. Studies show that intakes of 1.2 to 1.6 grams per kilogram of body weight per day help preserve lean mass and improve body composition during calorie restriction. For a 160-pound person, that’s 87 to 116 grams daily. Eating above 1.3 grams per kilogram is associated with gains in muscle mass, while dropping below 1.0 gram per kilogram increases the risk of muscle loss.
Practical Ways to Estimate Servings
You don’t need a food scale. A 3-ounce portion of cooked meat, poultry, or fish is roughly the size of your outstretched palm or a deck of cards. A tablespoon of peanut butter is about the size of a standard postage stamp’s width, and two tablespoons (7 grams of protein) is the size of a ping pong ball. An ounce of nuts, which gives you 4 to 6 grams, fits in one cupped handful. An ounce of hard cheese looks like three or four dice stacked together.
Using these visual cues, a day of adequate protein for most people could look like: two eggs at breakfast (12 grams), a palm-sized chicken breast at lunch (25 grams), a handful of almonds as a snack (5 grams), and a piece of fish with half a cup of lentils at dinner (roughly 30 grams). That totals about 72 grams with no measuring required.
Complete vs. Incomplete Proteins
Complete proteins contain all nine essential amino acids in sufficient amounts. Fish, poultry, eggs, beef, pork, dairy, and whole soy foods (tofu, edamame, tempeh, miso) are all complete. Incomplete proteins, which include most legumes, grains, nuts, seeds, and vegetables, contain the essential amino acids but in lower amounts for at least one.
The old advice that you need to carefully combine incomplete proteins at every meal (like rice and beans together) is outdated. Your body maintains a pool of amino acids that it draws from throughout the day. Eating a variety of protein sources across your meals is enough. If you had lentils at lunch and rice at dinner, your body can use the amino acids from both. The goal is balance over the course of 24 hours, not perfection at every sitting.