Protein 101: How Much You Actually Need and the Best Sources to Get It

Walk into any gym, scroll through any fitness account on social media, or pick up almost any health magazine, and you’ll be bombarded with messages about protein. Protein shakes, protein bars, high-protein everything. It’s become the most marketed macronutrient of our time.

But beneath all the noise, there are genuinely important things to understand about protein — what it does in your body, how much you actually need (which is different from what supplement companies want you to believe), and the best ways to get it from real food.

What Is Protein and Why Does It Matter?

Protein is one of the three macronutrients — along with carbohydrates and fat — that provide your body with energy and structural materials. But protein is unique in that its primary role isn’t energy provision. Protein is the body’s primary building material.

Every cell in your body contains protein. Muscles, organs, skin, hair, nails, enzymes, hormones, neurotransmitters, and antibodies are all made from protein. When you eat protein, your digestive system breaks it down into amino acids — the individual building blocks — which are then absorbed and used to repair and build tissues, produce hormones and enzymes, support immune function, and maintain fluid balance.

There are 20 amino acids in total. Your body can synthesize 11 of them on its own. The remaining 9 — called essential amino acids — must come from your diet. Foods that contain all 9 essential amino acids in adequate proportions are called complete proteins. Animal foods (meat, fish, eggs, dairy) are generally complete proteins. Most plant foods are not, which is why variety matters on a plant-based diet.

How Much Protein Do You Actually Need?

This is where things get nuanced, because the answer varies significantly depending on who you are and what your goals are.

The official Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day. For a 70kg (154 lb) person, that’s 56 grams per day. But the RDA represents the minimum needed to prevent deficiency in sedentary adults — it’s not necessarily optimal for health, and it’s definitely not optimal for active people.

More recent research suggests that significantly higher intakes are beneficial for most people:

For general health in moderately active adults: 1.2–1.6g per kg body weight. For a 70kg person, that’s 84–112g per day.

For building or maintaining muscle mass: 1.6–2.2g per kg body weight. For the same 70kg person, that’s 112–154g per day.

For older adults (over 65): Research consistently shows that older adults need more protein than younger people — at least 1.2–1.6g per kg — to combat age-related muscle loss (sarcopenia), which begins as early as your 30s and accelerates with age.

For weight loss: Higher protein intake (1.6–2.4g per kg) during caloric restriction helps preserve lean muscle mass while losing fat.

These numbers might sound high compared to what you’re currently eating, but they’re very achievable with a little planning.

Signs You Might Not Be Getting Enough Protein

Many people undereat protein without realizing it, particularly those following plant-based diets or those who skip breakfast and lunch. Signs of chronically low protein intake include:

Persistent hunger and cravings — protein is the most satiating macronutrient. When you’re consistently hungry shortly after eating, inadequate protein is often a factor.

Slow workout recovery — muscles need amino acids to repair after exercise. Without sufficient protein, recovery takes longer and performance suffers.

Loss of muscle tone — particularly noticeable over months or years of chronically low intake.

Brittle hair and nails — both are made primarily from protein. Deficiency often shows up here first.

Frequent illness — protein is essential for immune function. Low intake impairs your body’s ability to produce antibodies and immune cells.

Difficulty concentrating — neurotransmitters like dopamine and serotonin are synthesized from amino acids. Insufficient protein can affect mood and cognitive function.

The Best Food Sources of Protein

Animal Sources

Chicken breast: 31g protein per 100g cooked. One of the leanest, most protein-dense foods available.

Canned tuna: 25g protein per 100g. Affordable, shelf-stable, and incredibly versatile. Choose tuna in water over oil to keep calories lower.

Salmon: 25g protein per 100g cooked, plus exceptional omega-3 content. One of the best overall foods you can eat.

Eggs: 6g protein per egg. Complete protein, rich in choline, vitamin D, B12, and virtually every other essential nutrient. Whole eggs are far more nutritious than egg whites alone.

Greek yogurt: 10g per 100g (plain, full-fat). Also provides probiotics, calcium, and B vitamins.

Cottage cheese: 11g per 100g. High in casein protein, which digests slowly — making it ideal before sleep to support overnight muscle repair.

Plant Sources

Lentils: 9g per 100g cooked. Also one of the best sources of iron, folate, and prebiotic fiber.

Chickpeas: 9g per 100g cooked. Incredibly versatile — use in soups, stews, salads, roasted as a snack, or blended into hummus.

Edamame: 11g per 100g. One of the few plant foods that is a complete protein.

Tempeh: 19g per 100g. Fermented, more digestible than tofu, and one of the highest plant protein sources available.

Tofu (firm): 8g per 100g. Takes on any flavor beautifully — versatile enough to use in almost any cuisine.

Hemp seeds: 10g per 3 tablespoons. Also a complete protein and one of the best plant sources of omega-3 fatty acids.

Quinoa: 4g per 100g cooked. A complete plant protein that works as a grain substitute.

Black beans: 8g per 100g cooked. Rich in fiber, antioxidants, and iron as well.

Timing: Does It Matter When You Eat Protein?

For general health and weight management, total daily protein intake matters far more than precise timing. However, research does support a few timing principles worth noting:

Distribute protein across meals. Rather than eating very little protein at breakfast and lunch and loading up at dinner, spreading intake across 3–4 meals of 25–40g each maximizes muscle protein synthesis. The body can only utilize a certain amount of protein per meal for muscle building — the rest is used for energy or excreted.

Prioritize protein at breakfast. Eating protein in the morning significantly reduces hunger and cravings throughout the day. A high-protein breakfast is one of the most consistent findings in appetite regulation research.

Post-exercise protein. Consuming 20–40g of protein within a couple of hours after resistance training supports muscle repair and growth. However, the anabolic window is wider than once thought — total daily intake is more important than precise post-workout timing.

Do You Need Protein Supplements?

For most people eating varied whole foods, the answer is no. Protein supplements (powders, bars, shakes) are convenient and can fill gaps, but they’re not magic and they’re certainly not necessary. Whole food sources of protein come packaged with other valuable nutrients — vitamins, minerals, fiber, healthy fats — that protein supplements lack.

That said, protein powder can be a genuinely useful tool for people who struggle to meet their targets through food alone — particularly athletes, very active individuals, those following plant-based diets, or people who simply don’t have time for full meals. A high-quality whey or plant-based protein powder added to smoothies or oatmeal is a practical solution in those circumstances.

→ Read Next: The Complete Guide to Plant-Based Protein Sources

The Bottom Line

Protein is genuinely important — probably more so than most people realize. But you don’t need to obsess over it or spend a fortune on supplements. Focus on building meals around quality whole food protein sources at every meal, spread intake throughout the day, and prioritize protein particularly at breakfast. Whether you eat meat, follow a plant-based diet, or fall somewhere in between, hitting adequate protein targets is entirely achievable with a little planning and the right foods in your kitchen.