How Much Protein Do You Need Per Day?

The minimum versus the optimum

Official reference intakes, such as the Recommended Dietary Allowance of 0.8 g/kg per day used in North America and the similar population reference intake set by EFSA in Europe, are designed to prevent deficiency in most healthy adults. They were never intended to describe what maximises muscle growth or athletic performance.

For people who lift weights, sports nutrition organisations recommend considerably more. The ISSN position stand suggests 1.4 to 2.0 g/kg per day for most exercising individuals, and a joint statement from the American College of Sports Medicine and dietetic organisations suggests 1.2 to 2.0 g/kg. Our protein calculator uses these ranges as its starting point.

What the meta-analyses say

The most cited analysis on this topic, published in 2018, pooled 49 randomised trials involving more than 1,800 participants. It found that protein supplementation improved resistance-training gains in muscle mass and strength. The benefit for fat-free mass plateaued at an intake of about 1.6 g/kg per day on average, but the upper end of the confidence interval was around 2.2 g/kg. That is why 1.6 g/kg is often described as a solid target, and 2.2 g/kg as a level that covers almost everyone.

Protein appeared less influential than training itself, and its effect was smaller in people who were older or less trained. In other words, protein amplifies the response to training rather than replacing it.

Targets by goal

Your best target depends on your goal, body composition and training. During a calorie deficit, higher intakes may help preserve lean mass, which is why recommendations for dieting lifters tend to be higher. For people with obesity, calculating protein based on target or lean body weight, rather than total weight, often gives a more practical number.

• General health, sedentary adult: 0.8 to 1.0 g/kg
• Active adult or endurance athlete: 1.2 to 1.6 g/kg
• Building muscle in a surplus or at maintenance: 1.6 to 2.2 g/kg
• Fat loss while lifting, especially when lean: 1.8 to 2.7 g/kg
• Older adults who train: many researchers suggest at least 1.2 to 1.6 g/kg

How to split protein across meals

Muscle protein synthesis appears to respond to each protein-containing meal, so distributing intake across the day is a practical strategy. A review by Schoenfeld and Aragon suggested a target of about 0.4 g/kg per meal across at least four meals to reach roughly 1.6 g/kg per day, with up to about 0.55 g/kg per meal across four meals to reach 2.2 g/kg.

The old idea that the body can only use 20 to 30 grams of protein at a time is an oversimplification. Larger doses are not wasted; they may simply be used more slowly or for other purposes. Recent research suggests that a large protein dose can extend the muscle-building response over a longer period. Distribution is a useful optimisation, but total daily intake matters more.

Protein quality

Proteins differ in digestibility and amino acid content. Animal proteins such as dairy, eggs, meat and fish generally provide all essential amino acids in proportions that closely match human needs and are rich in leucine, an amino acid that acts as a key signal for muscle protein synthesis. Most plant proteins are somewhat lower in leucine or other essential amino acids and slightly less digestible.

Plant-based eaters can compensate by eating a little more total protein, choosing soy and blended protein sources, and combining legumes with grains. Research has shown that well-planned high-protein vegan diets can support muscle gain similar to omnivorous diets when total protein is matched.

Is high protein safe?

In healthy adults, studies of protein intakes well above 2 g/kg have not shown harmful effects on kidney function or bone health. The ISSN notes that intakes up to around 3 g/kg have been used in research without adverse effects in healthy, trained people. People with existing kidney disease are a separate case and should follow individual medical guidance.

Practical ways to hit your target

Build each meal around a protein source, then add carbohydrates, vegetables and fats. Keep convenient options available for busy days. A protein shake is optional but can be helpful if your schedule makes whole-food meals difficult.

• 150 g cooked chicken breast: about 45 g protein
• 200 g Greek yogurt: about 18 to 20 g
• 3 large eggs: about 18 g
• 100 g firm tofu: about 12 to 17 g depending on type
• 1 cup cooked lentils: about 18 g
• 1 can of tuna (drained, ~110 g): about 25 g