How much protein do you need per day based on your goal

Why protein is the king of macronutrients

If you could only optimise one aspect of your diet, protein should be it. The research is emphatic: a 2018 meta-analysis in the British Journal of Sports Medicine covering 49 studies and 1,863 participants found that protein supplementation produced an average gain of 0.3 kg of fat-free mass and 2.5 kg on the 1RM — a 9% strength improvement, in the paper's own words — when combined with resistance training. But protein is not only about muscle. It is the most satiating macronutrient (it keeps hunger away longer), it carries the highest thermic effect (your body spends 20-30% of protein calories just digesting it, versus 5-10% for carbohydrate and 0-3% for fat), and it is essential for bone health, immune function and tissue repair.

How much protein you need for your goal and your body

The answer depends on your weight, your activity level and your goal. The official reference figure (0.8 g/kg/day, the Institute of Medicine RDA; the WHO has used 0.83 g/kg/day since 2007) was set to prevent deficiency in the general population, not to optimise body composition. Modern research has revised those numbers substantially:

• Sedentary with no specific goal: 1.0-1.2 g per kg of bodyweight. An 80 kg man would need 80-96 g/day. Enough to maintain existing muscle mass and general health
• Losing fat with moderate exercise: 1.6-2.0 g per kg. Example: a 65 kg woman needs 104-130 g/day. High protein during a calorie deficit is critical: a McMaster University study (2016) found that people in a deficit eating 2.4 g/kg gained muscle while losing fat, something long considered impossible
• Building muscle: 1.6-2.2 g per kg. Morton's meta-analysis (BJSM 2018) puts around 1.6 g/kg/day as the point where extra lean-mass gains stop being detectable, but its confidence interval reaches 2.2, which is why the authors themselves suggest aiming for around 2.2 g/kg if maximising is the objective; Schoenfeld and Aragon, in a 2018 review in the Journal of the ISSN, recommend splitting it across at least four servings of about 0.4 g/kg
• Over 60: 1.2-1.6 g per kg. Sarcopenia, the age-related loss of muscle, begins around 30 and accelerates after 60. Raising protein alongside strength training is the best strategy against it
• Pregnancy and breastfeeding: 1.2-1.5 g per kg. Amino acid requirements rise to support fetal development and milk production

The definitive ranking of protein sources

Not all protein is equal. Quality comes down to two things: the amino acid profile (it should contain all nine essentials in useful proportions) and digestibility (what share your body actually absorbs). PDCAAS — the Protein Digestibility Corrected Amino Acid Score — runs from 0 to 1, where 1 is perfect.

• Whey protein: PDCAAS 1.0. 80-90 g of protein per 100 g of powder. Fast absorption, which is why it suits post-training. The most studied and most effective supplement option
• Whole egg: PDCAAS 1.0. 13 g of protein in two eggs (155 kcal). The yolk carries choline (essential for the brain), vitamin D and half the protein. Do not throw it away
• Skinless chicken breast: PDCAAS 0.92. 31 g of protein per 100 g (165 kcal). The best protein-to-calorie ratio of any meat. Grill it, bake it or shred it
• Wild salmon: PDCAAS 0.88. 25 g of protein per 100 g (208 kcal). It also brings 2.3 g of omega-3 (EPA+DHA) — the American Heart Association recommends two portions of oily fish a week
• Plain Greek yogurt: PDCAAS 1.0. 10 g of protein per 100 g (59 kcal). Rich in probiotics, calcium and vitamin B12. The best protein snack there is
• Lentils: PDCAAS 0.52. 9 g of protein per 100 g cooked (116 kcal). Low in lysine, an essential amino acid — combined with rice or bread they form a complete protein. They also bring 8 g of fibre per 100 g
• Firm tofu: PDCAAS 0.56. 8 g of protein per 100 g (76 kcal). Soy is the legume with the best amino acid profile. Soy phytoestrogens are safe at normal intakes according to current evidence

Distribution and timing: when to eat protein

The obsession with a 30-minute post-workout "anabolic window" is largely a myth. A meta-analysis by Schoenfeld, Aragon and Krieger (2013) concluded that what really matters is the daily protein total, not the precise moment you eat it. That said, the nuances are worth knowing:

• Spread protein across 3-5 meals of 25-40 g each. Your body cannot channel much more than 40 g from a single meal into muscle protein synthesis; the surplus is used as energy or excreted
• The minimum dose per meal to trigger muscle protein synthesis is 20-25 g. Below that the stimulus is not sufficient
• Before bed: 30-40 g of casein, a slow-digesting protein, improves overnight muscle protein synthesis according to a Maastricht University study. A large glass of milk or a bowl of cottage cheese does the job
• Post-workout: you do not need to sprint to the changing room for a shake. You have at least two to three hours after training to eat a protein-rich meal. The urgency is supplement marketing, not physiology

The five most common protein mistakes

• Believing you need supplements: you can hit your protein target perfectly well with real food. Shakes are a convenience, not a requirement. If you struggle to get there, whey is practical — but never obligatory
• Not counting plant protein: many people count chicken and eggs but ignore the 15 g in 200 g of chickpeas or the 8 g in a large glass of milk. It all adds up
• Eating all your protein in one meal: a 300 g steak has 75 g of protein, but only around 40 g of it can go into muscle. The rest is oxidised. Better to spread it across three or four servings
• Avoiding protein for fear of kidney damage: this myth has been refuted in more than 30 studies. In people with healthy kidneys there is no evidence that high protein (up to 3 g/kg) causes any renal problem
• Not adjusting while losing weight: when you lose weight you need MORE protein, not less. In a calorie deficit, high protein is what stops your body burning muscle for energy

How to hit your protein target without stress

The trick is simply including a protein source in every meal and snack. You do not need chicken at every sitting or a life built on shakes. A typical day for someone who needs 130 g might look like this: breakfast with Greek yogurt and eggs (30 g), lunch with chicken or fish (35 g), an afternoon snack of cottage cheese or nuts (15 g), and dinner with legumes or meat (35 g). That is 115 g with no supplements at all. Add a coffee with milk (5 g) and a little cheese (10 g) and you are at 130 g. With Renzy, every scanned meal shows your protein grams automatically and the dashboard tells you in real time how far you are from your daily target.