How Much Protein Should You Eat Per Day? (Science-Based Guide)

Protein Requirements by Goal

The Science: What the Research Actually Says

A 2018 meta-analysis in the British Journal of Sports Medicine analysed 49 studies covering 1,863 participants. It found protein supplementation significantly increased muscle mass from resistance training, with gains plateauing at approximately 1.62g per kg per day during a caloric surplus. During fat loss phases, higher intakes of 1.8–2.4g/kg help preserve lean mass.

Fat Loss vs Muscle Gain: Different Protein Needs

Muscle gain: 1.6–2.0g/kg is sufficient when eating in a caloric surplus. The extra calories and carbohydrates provide an anabolic environment that means you do not need to push protein extremely high.

Fat loss: Higher protein (1.8–2.4g/kg) is more important during a deficit because the risk of muscle breakdown increases when calories are restricted. Protein becomes even more “expensive” metabolically — your body uses it for energy if intake of other macros is too low.

The Too-Much Protein Myth

For healthy adults with normal kidney function, high protein intakes (up to 3.5g/kg) have not been shown to cause kidney damage in research. The concern about protein and kidneys applies specifically to people with existing kidney disease. For healthy people, the practical upper limit is simply what you can comfortably fit into your calorie budget.

Best Protein Sources

Animal sources: Chicken breast (31g/100g), tuna (26g), Greek yoghurt (10g), eggs (13g/100g), cottage cheese (11g), lean beef (26g).

Plant sources: Tofu (17g/100g), tempeh (19g), edamame (11g), lentils (9g cooked), black beans (8g). Combine plant sources to ensure complete amino acid profiles.