Protein Per Kg of Bodyweight: How Much Do You Actually Need?

Protein is the most debated macronutrient in fitness — and also the most misunderstood. Government recommendations tell you one thing; bodybuilding forums tell you another; your trainer may say something different entirely. The evidence base has actually converged quite clearly in recent years. Here's what it says.

The RDA Is Not an Optimal Sports Intake

The Recommended Dietary Allowance (RDA) for protein in the United States is 0.8 g per kg of bodyweight per day. This figure represents the minimum intake needed to prevent protein deficiency in the average sedentary adult — not the optimal intake for someone who exercises regularly. Treating the RDA as your protein target if you train is like treating the minimum speed limit as your target driving speed.

Protein Targets by Goal

• Sedentary adults: 0.8–1.0 g/kg — meets basic needs
• Active adults (recreational exercise 2–3x/week): 1.2–1.6 g/kg
• Muscle gain (resistance training 3–5x/week): 1.6–2.2 g/kg
• Fat loss while preserving muscle: 2.3–3.1 g/kg — higher protein counters muscle protein breakdown in a calorie deficit
• Endurance athletes: 1.4–1.7 g/kg — muscle repair from volume training
• Older adults (50+): 1.2–1.6 g/kg — counteracts age-related muscle loss (sarcopenia)

For a practical example: a 75 kg person aiming to build muscle should target 120–165 g of protein per day. At 3–4 meals, that means roughly 30–55 g of protein per meal.

Does More Protein Always Mean More Muscle?

Not beyond the threshold. Once protein intake exceeds approximately 2.2 g/kg/day, additional protein provides no further anabolic benefit — it is simply oxidized for energy or excreted. This is why intakes at 3–4 g/kg, sometimes promoted in bodybuilding communities, offer no advantage for muscle growth and may displace carbohydrates that are valuable for training performance.

Best Protein Sources for Hitting Your Target

• Chicken breast: ~31 g protein per 100 g
• Greek yogurt (plain, 0%): ~10 g per 100 g
• Cottage cheese: ~11 g per 100 g
• Eggs: ~13 g per 100 g
• Canned tuna: ~25 g per 100 g
• Tempeh: ~19 g per 100 g
• Edamame: ~11 g per 100 g
• Whey protein powder: ~25 g per 30 g serving

Does Protein Timing Matter?

Total daily protein matters far more than precise timing. That said, distributing protein across 4+ meals (roughly every 3–4 hours) provides repeated stimulation of muscle protein synthesis throughout the day — superior to consuming the same total in 1–2 large meals. Pre-sleep protein (30–40 g of casein or cottage cheese) has also shown benefits for overnight muscle protein synthesis in multiple studies.