Key Takeaways

• Protein isn't just "good for you," it's essential. It builds and repairs tissues, forms blood components, antibodies, and enzymes, and supports countless cellular processes your body depends on daily.
• Target at least 1.2-1.6 grams, and up to 2.2 grams, of protein per kg of body weight daily (0.55-1g per lb). This range supports muscle maintenance, healthy aging, and satiety, particularly for active individuals.
• Protein quality matters as much as quantity. High-quality proteins are fully digestible and deliver all nine essential amino acids. Top sources include whey, milk proteins, eggs, chicken, turkey, beef, and fish. For plant-based diets, prioritize soy protein isolate, pea protein isolate, and pea/rice blends.
• Relying on lower-quality protein sources means you may need to eat significantly more volume to meet the same amino acid requirements, and even then your body may still come up short.

Everywhere you look, there's a new high-protein food hitting shelves. There are protein powders and bars, protein chips, protein desserts, even protein water (yes, really). There's a market for it because protein matters, and people, now more than ever, know it.

Most gymgoers think of protein as a muscle-builder, which it is. But your body also relies on this macronutrient to build and repair tissues like hair, skin, and connective tissue; to form blood components, antibodies, and enzymes; and to support countless cellular processes. While your body can use protein for energy, it prefers carbs and fat.

Protein isn't just for lifters. It's one of the fundamental building blocks of your entire body. And while there are more options than ever for increasing your protein intake, little conversation revolves around protein sources and quality. So, what matters more: How much protein do you eat, or the quality of the protein itself?

So, how much protein should you consume?

The longstanding U.S. Recommended Dietary Allowance (RDA) was 0.8 grams per kilogram of body weight (0.36 g/lb), approximately 50 grams for a 150-pound person. This amount was designed to meet what was considered the needs of most healthy adults. However, the 2025-2030 Dietary Guidelines now recommend 1.2-1.6g/kg, reflecting what many experts have been recommending for years.

Experts note that the RDA is primarily based on sedentary adults and may not reflect the daily needs of those who participate in physical activity or those trying to increase muscle. Some suggest consuming up to 2.2 grams of protein per kilogram of body weight (or 1 gram per pound), which is about 150 grams of protein for a 150-pound adult. This amount may help maintain muscle, support healthy aging, and promote satiety during weight loss.

Some research has shown that it may be beneficial to spread out your protein intake across several meals. However, a more recent 2023 study challenged this notion. The study found that muscle protein synthesis was greater in magnitude and sustained for longer in participants who ingested 100 grams of protein compared to 25 grams. And don't worry about eating protein within an hour of your workout—common gym lore known as the "anabolic window". Researchers found that your overall protein intake matters significantly more than the exact timing. It is most important to prioritize hitting your overall protein intake however it best fits into your schedule and you'll see progress.

To find your protein target per meal:

1. Find your body weight in pounds.
2. Multiply your body weight by 0.55-1, depending on your total protein goals.
3. Divide by the number of meals you have each day.

Note: Up to 1g per pound is a commonly used, safe guideline for optimizing muscle gain or preserving muscle during fat loss, not a universal requirement. Individual needs may vary.

What makes protein high quality?

All protein is made up of amino acids, and each one plays a specific role in how your body functions. Of the twenty total amino acids, nine of them are essential—meaning you can't make them yourself and must get them from your diet.

Protein quality is defined by how efficiently it is digested and whether it delivers all the amino acids needed for your body to function and grow. Here's a quick rundown of the most common ways protein quality is measured:

Protein digestibility corrected amino acid score (PDCAAS)

PDCAAS is a long-standing method for evaluating protein quality, scored on a scale from 0 to 1. Researchers analyze a protein's amino-acid profile, compare it to human requirements, identify the "limiting" amino acid, and then multiply that value by how well the protein is digested based on known digestibility values. Because scores are capped at 1.0, different proteins can appear identical on paper even when they differ in practice.

Digestible indispensable amino acid score (DIAAS)

DIAAS measures the digestibility of each essential amino acid at the end of the small intestine, where absorption occurs, offering a more accurate picture than fecal-based PDCAAS estimates because DIAAS scores aren't capped at 1.0. In practice, this means a protein like whey can score above 1.0 on DIAAS, more accurately reflecting its superior quality. The result is a clearer picture of how much usable protein your body actually receives.

However, according to a report by the Food and Agriculture Organization (FAO), there are a few limitations to using DIAAS. Despite its comparative accuracy to PDCAAS, it requires invasive animal studies that are expensive, operationally difficult, and can raise some ethical concerns.

How to identify high-quality protein in real life

Most foods and supplements don't advertise their protein quality scores, and there isn't, unfortunately, a single database that compiles those scores in any one place. If you look hard enough, there are some studies—such as this one from the Journal of Nutrition—that list popular protein sources by quality score. A few high-quality protein sources include:

Animal proteins

• Whey protein (protein bars and shakes are a good choice): 1.00
• Milk proteins (casein, whey blends): 1.00
• Eggs & egg whites: 1.00
• Chicken, turkey, beef: 0.92-1.00
• Fish: 0.90-1.00

Source: Glanbia

Plant-based proteins

• Tofu/tempeh: 0.90-0.95
• Soy protein isolate: 1.00
• Pea protein isolate: 0.82-0.89
• Rice + pea protein blends: 0.90-1.00

Generally speaking, animal proteins score higher because they're more digestible and deliver all nine essential amino acids in optimal amounts. Plant proteins aren't "bad," but they tend to be less complete and less bioavailable. If you avoid animal proteins, you just need to be more intentional.

Registered dietitian and vegan nutrition expert Virginia Messina explains:

For those eating a vegan diet and getting all of their protein from plants, diets should always include legumes — beans, peanuts, and soyfoods — to ensure adequate intake of the essential amino acid lysine.

Does protein quality or quantity matter more?

They both matter.

You need enough protein to support your body's basic functions and maintain muscle mass, which is a predictor of longevity. But if you rely heavily on lower-quality protein sources (like oats, legumes, and brown rice), you'll need to eat significantly more to reach your total protein target, and your body has to work harder to extract the essential amino acids it needs.