How Much Protein Do You Actually Need Per Day?

💡 TL;DR: The official RDA of 0.8 g of protein per kg of body weight is the floor that prevents deficiency, not the amount that helps you thrive. Most active adults do better around 1.2 to 1.6 g/kg, people building muscle up to about 1.6 to 2.2 g/kg, and adults over 65 around 1.0 to 1.2 g/kg to slow muscle loss. Total daily protein matters more than exact timing, and for healthy kidneys a higher intake is safe.

Ask ten people how much protein you need in a day and you will get ten answers, from the number on a cereal box to a bodybuilder's shake schedule. The confusion is understandable, because the single official figure most often quoted, the RDA, was never meant to answer the question people are actually asking. It tells you the minimum to avoid a deficiency, not the amount that keeps your muscles, appetite and metabolism working at their best. This guide walks through what the evidence really says, by body weight, age and goal, and how to hit a sensible target with real food.

The RDA is a floor, not a target

The Recommended Dietary Allowance for protein is 0.8 grams per kilogram of body weight per day, or about 0.36 grams per pound. For a 70 kg (154 lb) adult that is roughly 56 grams a day; for a 140 lb sedentary person, Harvard Health puts it at about 53 grams. The "Daily Value" of 50 grams you see on packaged food comes from the same baseline. The catch is what the RDA is for: it is set to cover the needs of nearly all healthy people, which makes it the amount that keeps you from getting sick, not the amount that helps you flourish. The Institute of Medicine also gives a much wider Acceptable Macronutrient Distribution Range of 10 to 35% of daily calories from protein, and even the bottom of that range works out higher than the RDA for most people.

How much protein do you actually need?

The honest answer is that it depends on your body weight, your activity and your goal. Grams per kilogram is the most reliable way to scale it, because a 55 kg office worker and a 95 kg athlete have very different needs. The table below sums up where the research lands for healthy adults.

Your situation	Protein target (per kg/day)	Example: 70 kg adult
Sedentary, general health	0.8 to 1.0 g/kg	56 to 70 g
Active, regular exercise	1.2 to 1.6 g/kg	84 to 112 g
Losing weight (preserve muscle)	1.2 to 1.6 g/kg	84 to 112 g
Building muscle, strength training	1.6 to 2.2 g/kg	112 to 154 g
Older adult (65+)	1.0 to 1.2 g/kg	70 to 84 g

These ranges come from bodies like the International Society of Sports Nutrition, which recommends 1.4 to 2.0 g/kg for physically active people, and from clinical guidance for older adults. If you are sedentary and healthy, the lower end is plenty. If you train, are dieting, or are getting older, aiming higher is where the real benefits show up.

Why most people do better above the RDA

Three well-studied benefits push the useful amount above the bare minimum. The first is muscle. Protein supplies the amino acids that build and repair muscle, and this matters most when you exercise. A large 2018 systematic review and meta-analysis of 49 trials found that pairing resistance training with more protein increased muscle and strength, with gains rising up to about 1.6 g/kg per day and then leveling off. If you lift or want to hold onto muscle, that is a practical ceiling for most people. It is also why protein and strength training work as a pair for a longer, stronger life.

The second is appetite and weight. Protein is the most filling of the three macronutrients, so a higher-protein meal tends to keep you satisfied for longer and can make it easier to eat fewer calories without feeling deprived. When you are losing weight, enough protein also protects lean muscle, so more of what you lose is fat. The third is simply recovery and everyday resilience: adequate protein supports your immune system, tissues and enzymes, the quiet maintenance your body runs on around the clock.

Protein and healthy ageing

From around your forties, muscle slowly starts to slip away in a process called sarcopenia, and the body also becomes a little less efficient at turning protein into muscle. That is why expert groups such as PROT-AGE and ESPEN recommend older adults aim for 1.0 to 1.2 g/kg per day, more than the RDA, rising to 1.2 to 1.5 g/kg during illness or recovery. Getting enough protein, paired with some resistance exercise, is one of the most effective ways to stay strong, mobile and independent later in life. It is part of the same story as how the body and mind can keep adapting well into old age. This is general information, not medical advice, so check with your doctor if you have a health condition.

Timing: total matters most, spacing helps

You may have heard you must eat protein within minutes of a workout, or that your body can only use a fixed amount at once. The evidence is calmer than that. The single biggest lever is your total protein for the day: hit that, and the finer details matter far less. That said, spreading protein across meals is a smart habit. To maximise muscle building, research suggests 20 to 40 grams per meal (roughly 0.25 to 0.4 g/kg), every three to four hours, with each meal carrying enough of the amino acid leucine to switch on muscle repair. In practice that means a protein source at breakfast, lunch and dinner, rather than almost none in the morning and a huge dinner.

Protein quality: animal, plant, and how to combine

Not all protein is equal. Complete proteins, which contain all nine essential amino acids in good amounts, come mostly from animal foods: meat, fish, eggs and dairy, plus soy. Most plant proteins are lower in one or two amino acids, which is why variety is the key: combine legumes with grains, nuts and seeds across the day and you cover the gaps easily. Plant eaters may aim a little higher on total protein, because it is digested slightly less efficiently, but excellent options exist, from lentils and beans to tofu, tempeh and edamame. You do not need supplements to get there; whole foods do the job, with protein powder as a convenience rather than a requirement.

Best protein sources

Hitting your target is easier when you know roughly what foods deliver. These are approximate values per 100 grams (cooked, where relevant), based on USDA data.

Food	Protein (per 100 g)	Notes
Chicken breast, cooked	about 31 g	Lean, complete protein
Canned tuna or cooked salmon	about 25 to 26 g	Adds omega-3 fats
Lean beef, cooked	about 26 g	Rich in iron and B12
Greek yogurt, plain	about 10 g	Easy high-protein snack
Firm tofu	about 9 to 10 g	Complete plant protein (soy)
Cooked lentils	about 9 g	Also high in fibre
Eggs	about 6 g each	Very high quality protein

A day that reaches 100 grams is not as hard as it sounds: two eggs at breakfast, a can of tuna or a chicken breast at lunch, Greek yogurt as a snack, and a palm-sized portion of fish or tofu with lentils at dinner will get most people there.

Can you eat too much protein?

For most healthy people, the fear of "too much" protein is overstated. The most common worry is the kidneys, but a 2018 meta-analysis of healthy adults found that higher-protein diets did not harm kidney function compared with lower intakes; the temporary rise in filtration appears to be a normal adaptation. The important exception is people with existing kidney disease, who should follow their doctor's advice. Very high intakes offer no extra muscle benefit past the plateau, can crowd out other nutritious foods, and are simply unnecessary. As with most things in nutrition, more is better only up to a point, and after that it is just more. Again, this is general information, not medical or dietary advice for your specific situation.

FAQ

Source: Harvard Health, "How much protein do you need every day?"; Morton et al. (2018), British Journal of Sports Medicine; ISSN Position Stand: Protein and Exercise (2017).

About the author

Dao Huy (Lucas) is a professional Vietnamese translator working across English, Vietnamese, Chinese and French (EN to VI to ZH to FR), with 7+ years in medical, legal, financial and academic translation. I write these explainers out of curiosity and a habit of reading the primary research. Nutrition is a field where a single number, like grams of protein per kilogram, gets flattened as it travels from a study into a headline, and I enjoy putting the nuance back.

If you need that same careful, accurate work across languages, I offer English to Vietnamese translation, certified Vietnamese document translation and multilingual localization. You can read more or get a quote at daohuy.com.