The best protein to eat depends on your goal, but if you’re looking for a single standout, whole eggs, chicken breast, and fish consistently rank at the top for quality, digestibility, and nutrient density. Milk protein scores highest on laboratory measures of protein quality, with a digestibility score of 1.18 out of 1.0 (scores above 1.0 are possible on this scale). But real-world eating involves more than lab scores. The best protein is the one that fits your body, your goals, and your plate.
How Protein Quality Is Measured
Not all protein is created equal. Scientists rank protein sources by how completely your body can digest and use their amino acids, the building blocks your cells need. The current gold standard is called DIAAS (Digestible Indispensable Amino Acid Score), which measures how well each essential amino acid in a food gets absorbed individually. On this scale, milk protein concentrate scored 1.18, whey protein isolate ranked close behind, and animal proteins generally outperformed plant sources. A corn-based cereal scored just 0.01, essentially providing almost no usable protein despite technically containing some.
The practical takeaway: animal proteins like dairy, eggs, meat, and fish deliver amino acids your body can absorb more efficiently than most plant proteins. That doesn’t mean plant proteins are useless. It means you may need to eat a bit more of them or combine different sources to get the same effect.
Best Proteins for Building Muscle
If you’re trying to build or maintain muscle, the amino acid leucine is what matters most. Leucine acts as the “on switch” for muscle repair and growth after exercise. Whey protein contains about 13.6% leucine by weight, making it the richest source available. Casein (the other protein in milk) comes in at around 10.2%, and soy protein isolate at 8.0%.
That gap in leucine content translates directly into results. Studies comparing muscle protein synthesis (the process your body uses to rebuild muscle tissue) show that plant proteins like soy and wheat produce a lower muscle-building response than animal proteins, even when the total grams of protein are matched. For someone lifting weights or recovering from exercise, whey protein, chicken breast, eggs, and fish are the most effective choices per gram consumed.
A standard 3-ounce portion of chicken, beef, pork, or fish provides about 21 grams of protein. A single egg delivers 6 grams. To hit the same muscle-building threshold from plant sources, you’d typically need larger portions or strategic combinations.
Best Proteins for Feeling Full
If your goal is weight management, satiety matters as much as protein quality. A study comparing whey, casein, soy, and pea protein found that casein and pea protein were the clear winners for appetite suppression. Both reduced hunger significantly more than soy over a four-hour window and triggered higher levels of peptide YY, a gut hormone that signals fullness to your brain. Whey fell somewhere in the middle.
This is one area where a plant protein actually outperforms some animal sources. Pea protein matched casein for satiety, likely because both digest slowly, keeping amino acids trickling into your bloodstream for hours. If you’re trying to eat less without feeling deprived, slower-digesting proteins like casein (found in cottage cheese and Greek yogurt) or pea protein can help you stay satisfied between meals.
Highest Protein Foods by Density
When you’re trying to hit a protein target without overeating, calorie efficiency matters. These foods pack the most protein per ounce:
- Beef or turkey jerky: 10 to 15 grams per ounce
- Dry roasted edamame: 13 grams per ounce
- Chicken, turkey, beef, pork, lamb, or fish: 7 grams per ounce
- Low-fat hard cheese: 7 grams per ounce
- Shrimp, crab, and lobster: 6 grams per ounce
- Eggs: 6 grams each
- Nuts and seeds: 4 to 6 grams per ounce
A piece of chicken or fish the size of a deck of cards (about 3 ounces) gives you roughly 21 grams of protein. That’s a useful mental shortcut for meal planning.
Plant Proteins Are Better Than Their Reputation
Plant proteins have long been called “incomplete” because individual plant foods tend to be low in one or more essential amino acids. But this label is somewhat misleading. Research published by the American Heart Association confirmed that plant foods collectively contain all essential amino acids. A diet built on staples like rice, beans, potatoes, and corn, with some vegetables and fruit, provides every amino acid your body needs. You don’t even need to combine them in the same meal. Your body pools amino acids throughout the day.
Where plant proteins genuinely fall short is digestibility and leucine content. You’ll absorb less usable protein from a cup of lentils than from a chicken breast of equivalent protein content. For most people eating a varied diet, this difference is easy to overcome by simply eating a bit more total protein or including a wider range of plant sources. For athletes pushing hard, though, it can be worth supplementing with a high-leucine option like whey or strategically combining legumes with grains.
Long-Term Health Favors a Mix
Protein quality for muscle and protein quality for longevity aren’t the same conversation. A large study tracking over 400,000 people for 16 years found that higher plant protein intake was associated with lower rates of death from cardiovascular disease and all causes. Participants who replaced just 3% of their daily calories from animal protein with plant protein were 10% less likely to die during the study period.
This doesn’t mean animal protein is dangerous. It likely reflects the overall dietary pattern: people eating more beans, lentils, and nuts tend to eat more fiber, more antioxidants, and less processed meat. The lesson isn’t to avoid chicken or fish. It’s that leaning on plant proteins for a meaningful portion of your intake offers cardiovascular benefits that pure muscle-building metrics won’t capture.
How Much You Need
The baseline recommendation for adults is 0.8 grams of protein per kilogram of body weight, which works out to about 55 grams daily for a 150-pound person. Athletes and highly active people benefit from 1.2 to 1.5 grams per kilogram. The 2025 Dietary Guidelines for Americans recently shifted the general recommendation upward to 1.2 to 1.6 grams per kilogram, translating to roughly 82 to 108 grams per day for someone weighing 150 pounds.
For healthy kidneys, this range is considered safe. But pushing protein intake to extremes, well beyond 1.6 grams per kilogram, can stress your kidneys over time, even if they’re currently healthy. There’s no benefit to consuming massive quantities beyond what your body can use for muscle repair and daily function. Spreading your protein across three or four meals tends to be more effective than loading it all into one sitting, since your body can only process so much at once for muscle-building purposes.
Putting It Together
For most people, the best approach is building meals around a core of high-quality, lean animal proteins (chicken, fish, eggs, Greek yogurt) while regularly including plant proteins like beans, lentils, edamame, and nuts. This combination gives you the digestibility and leucine content that support muscle health, the slow-digesting proteins that keep you full, and the long-term cardiovascular benefits that come with plant-based eating. If you follow a fully plant-based diet, focus on variety, eat slightly more total protein to compensate for lower digestibility, and consider pea protein as a supplement that rivals dairy for both satiety and amino acid content.