How Much Protein Per Day Do You Actually Need?
Most people think they're eating enough protein. Most people are wrong.
A 2018 analysis published in the American Journal of Clinical Nutrition found that around 46% of older adults — and a surprising number of younger, active adults — consistently fall short of the protein their body actually needs. Not by a little, either. By enough to noticeably affect muscle mass, recovery, and energy.
If you've ever finished a gym session and wondered why your progress has stalled, or you're cutting calories and watching the scale drop along with your strength, protein intake is worth looking at seriously.
This guide breaks down the real numbers: what the science says, how much protein per day you actually need based on your goal, the best foods to hit that target, and how to track it without obsessing over every gram.
The Science Behind Protein Requirements
Protein is made up of amino acids — your body uses them to build and repair muscle tissue, produce enzymes and hormones, support immune function, and keep you feeling full between meals.
Unlike carbohydrates and fat, your body doesn't store amino acids. You need a regular supply from food. When you don't get enough, your body starts breaking down muscle tissue to meet its needs — which is the opposite of what most people want.
The official Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day. For a 75kg (165lb) person, that works out to about 60g of protein per day.
Here's the catch: the RDA is not a target. It's a minimum — the floor, not the ceiling. It was designed to prevent deficiency in sedentary adults, not to optimise body composition, support athletic performance, or help with weight management.
Sports nutrition research has moved well beyond that number. Studies consistently show that active adults benefit from significantly higher daily protein intake, and the effects on muscle retention, fat loss, and recovery are well documented.
How Much Protein Do You Actually Need?
The right amount depends on your goal, your body weight, and how active you are.
For General Health (Sedentary or Lightly Active)
If you're not training intensively, the 0.8g/kg RDA is a hard floor — don't go below it. A more useful target for general health and healthy ageing is 1.0–1.2g per kg of body weight per day. For a 75kg person, that's roughly 75–90g daily.
This range supports muscle maintenance, immune function, and metabolic health without requiring dramatic dietary changes. Older adults (65+) benefit from pushing toward the higher end, since the body becomes less efficient at using dietary protein as we age — a phenomenon researchers call "anabolic resistance."
For Weight Loss
When you're in a calorie deficit, keeping protein high protects your muscle mass. Your body is looking for energy wherever it can find it — and if protein intake drops, muscle tissue becomes fair game.
Research supports 1.2–1.6g per kg of body weight as a practical target during fat loss phases. Some studies go higher (up to 2.4g/kg) for very lean individuals or those doing heavy resistance training while cutting.
A 70kg woman aiming to lose weight would target roughly 84–112g of protein per day. A 90kg man would aim for 108–144g per day. The higher intake also helps because protein is more satiating than carbs or fat — you stay fuller on fewer calories.
For Muscle Building
The most commonly cited target for maximising muscle protein synthesis is 1.6–2.2g per kg of body weight per day. These numbers come from a 2017 meta-analysis by Morton et al. published in the British Journal of Sports Medicine, which reviewed 49 studies and over 1,800 participants.
Going above 2.2g/kg shows diminishing returns in most research — your body can only use so much for muscle building at once, and the excess gets used for energy or excreted. For a 75kg person training for muscle gain, that's a target of around 120–165g of protein daily.
Spreading that protein across 3–5 meals also matters. Research suggests each meal should include at least 20–40g of protein to maximally stimulate muscle protein synthesis. Eating 150g in one sitting doesn't give you the same results as spreading it evenly through the day.
For Endurance and Strength Athletes
If you're running marathons, cycling long distances, or lifting competitively, your protein needs are higher than the general population. Endurance athletes tend to fall in the 1.4–1.7g/kg range, while strength athletes sit closer to the 1.6–2.2g/kg end — similar to muscle building targets, but for different reasons (repair from high training volume rather than hypertrophy).
Best High-Protein Foods to Hit Your Daily Target
You don't need protein shakes to hit your numbers — though they help. These whole foods make it straightforward.
Animal sources (per typical serving):
- Chicken breast (100g cooked) — 31g protein
- Tuna (1 can, 185g drained) — 39g protein
- Salmon fillet (150g) — 30g protein
- Lean beef mince (100g cooked) — 26g protein
- Greek yoghurt (200g, full fat) — 17g protein
- Cottage cheese (200g) — 22g protein
- Eggs (2 large) — 12g protein
Plant sources (per typical serving):
- Edamame (150g) — 19g protein
- Tempeh (100g) — 19g protein
- Lentils (200g cooked) — 18g protein
- Chickpeas (200g cooked) — 15g protein
- Tofu (150g firm) — 15g protein
- Quinoa (200g cooked) — 8g protein
When whole food isn't enough:
- Whey protein shake (1 scoop) — 20–25g protein
- Casein protein shake (1 scoop) — 24–26g protein
A practical day hitting 150g of protein might look like: Greek yoghurt and eggs at breakfast (29g), chicken and lentils at lunch (49g), a protein shake post-workout (22g), and salmon with edamame at dinner (49g). That's entirely achievable with normal food — no eating until you're uncomfortable.
How to Track Your Protein Intake Without Losing Your Mind
Manual food logging — weighing everything, searching databases, calculating macros — is accurate but time-consuming. Most people stick with it for a week, then quietly give up.
The smarter approach is letting AI do the heavy lifting. With Nutrify AI, you photograph your meal and the AI identifies the food, estimates the portions, and logs the macros automatically. No barcode scanning, no hunting through a database of 8 million foods hoping someone else entered the same thing correctly.
You set your daily protein target — the app calculates it based on your weight, goal, and activity level — and it tracks in real time how close you are. Hit your target and the app shows you. Miss it at 8pm and it flags a quick snack suggestion to close the gap.
The difference between people who consistently hit their protein goals and people who don't is rarely motivation. It's usually awareness. When you can see the number in real time throughout the day, you make different choices.
Common Protein Myths — Debunked
"Your body can only absorb 30g of protein per meal."
Not true. Your body absorbs all the protein you eat — absorption isn't the limiting factor. What research actually shows is that around 20–40g per meal is optimal for stimulating muscle protein synthesis. Above that, the extra protein is still digested and used for other purposes (energy, etc.) — it's not wasted, it just doesn't contribute more to muscle building in that sitting.
"High protein diets damage your kidneys."
This concern comes from studies on people with pre-existing kidney disease, where high protein intake can accelerate decline. In healthy adults, there's no solid evidence that a high protein diet causes kidney problems. A 2016 review in the Journal of Nutrition and Metabolism found no adverse effects on kidney function in healthy individuals eating up to 2.8g/kg per day.
"Plant protein doesn't count the same as animal protein."
Plant proteins are often lower in one or more essential amino acids — particularly leucine, which is key for muscle protein synthesis — and they tend to be less bioavailable. But this doesn't mean plant protein is useless. It means you may need to eat slightly more of it, and combining different sources (legumes and grains, for example) helps cover the full amino acid profile. For vegans, aiming toward the higher end of protein recommendations is a practical strategy.
"More protein always means more muscle."
Beyond roughly 2.2g/kg per day, additional protein doesn't produce additional muscle growth in most studies. It can still be useful during aggressive cuts (to preserve muscle while in a deficit), but if your goal is pure muscle building, the ceiling is lower than supplement marketing would have you believe.
Start Tracking Protein the Easy Way
Knowing your daily protein target is step one. Actually hitting it consistently is what moves the needle — and that's where most people get stuck.
Nutrify AI removes the friction. Photograph your meals, let the AI calculate the macros, and watch your protein total build through the day. Set your goal once, and the app keeps score for you.
Download Nutrify AI free on iOS and Android →
No manual logging. No spreadsheets. Just a running total that keeps you on track.
