How Much Protein Do You Need Per Day?

The Official Recommendation vs What Active People Actually Need

The Australian recommended daily intake (RDI) for protein is 0.84g per kilogram of body weight for adult men and 0.75g per kilogram for adult women. These numbers represent the minimum required to prevent deficiency in sedentary adults. They are not targets for people who exercise, age actively, or want to build or preserve muscle mass.

For anyone who trains regularly or is trying to change their body composition, the current research points to a significantly higher range.

Protein Targets by Goal

For Muscle Building

The most cited and widely supported range from sports nutrition research is 1.6 to 2.2g of protein per kilogram of body weight per day for people aiming to build muscle. This range comes from multiple meta-analyses published over the past decade, including work by researchers like Stuart Phillips at McMaster University and the comprehensive 2018 meta-analysis published in the British Journal of Sports Medicine.

A practical example: a 75kg person trying to build muscle should aim for roughly 120 to 165g of protein per day. The lower end of that range (around 1.6g per kg) captures most of the benefit. Going beyond 2.2g per kg does not appear to produce additional muscle-building results for most people.

For Weight Loss While Preserving Muscle

During a calorie deficit, protein needs actually increase. When you are eating less than your body burns, muscle protein is at risk of being broken down for energy. Research suggests that 1.8 to 2.4g per kilogram is appropriate when dieting, particularly if you are strength training. Higher protein intake during a deficit also helps with satiety, making it easier to maintain the calorie reduction.

For General Health and Active Living

If you exercise regularly but are not specifically trying to build muscle or lose fat, 1.2 to 1.6g per kilogram is a reasonable and well-supported target. This is significantly above the official RDI but more achievable through whole food alone without supplementation for many people.

For Older Adults

Protein needs increase with age because of a phenomenon called anabolic resistance: the body becomes less efficient at using dietary protein to build and maintain muscle. Research suggests adults over 65 benefit from 1.6 to 2.0g per kilogram, distributed across meals rather than concentrated in one sitting. This is an area where protein supplementation is genuinely useful.

Does Protein Timing Matter?

There was a period when the "anabolic window" concept was heavily promoted in fitness circles: the idea that you had to consume protein within 30 minutes of training or the session was wasted. The research has not supported that strict timeline.

What the evidence does suggest is that total daily protein intake matters more than the precise timing of any individual meal. Spreading protein reasonably evenly across 3 to 4 meals through the day appears to be slightly more effective for muscle protein synthesis than eating the same total amount concentrated in one or two large meals. Each meal should ideally contain at least 20 to 30g of protein to maximise the per-meal muscle-building response.

Training around meal times is sensible, but obsessing over a precise post-workout window is not necessary for most people.

Protein Quality: Not All Grams Are Equal

Protein quality refers to how completely a food provides the essential amino acids your body cannot make itself. Animal proteins (meat, fish, eggs, dairy) are generally complete. Most plant proteins are not, though a well-varied plant-based diet can provide all essential amino acids across the day.

For supplementation purposes, this means that 30g of protein from a whey isolate delivers more usable amino acids for muscle building than 30g of protein from a plant source with an incomplete amino acid profile. If you are using plant protein, a pea-rice blend or another combination that covers the full essential amino acid spectrum is worth prioritising.

Meeting Your Target Through Food First

The most straightforward way to increase protein intake is through whole food. A 150g chicken breast provides around 45g of protein. Two eggs provide roughly 12g. A 170g tin of tuna delivers about 35g. 200g of Greek yogurt contributes around 20g. A 100g serve of cooked lentils provides about 9g.

A day that includes one of each of those items already delivers around 120g of protein, which hits the daily target for a 75 to 80kg person aiming to build muscle. Protein powder becomes most useful when whole food options are inconvenient, when you are travelling, or when your protein target is high enough that reaching it through food alone becomes impractical or expensive.

When More Is Not Better

Protein above roughly 2.2g per kilogram per day does not appear to produce additional muscle-building benefit for most people. Very high protein intakes are not dangerous for people with healthy kidneys, but they are unnecessary and expensive. Calories devoted to excess protein beyond what the body can use for muscle protein synthesis are simply metabolised for energy, like any other macronutrient.

The exception is during aggressive fat loss phases, where some research supports intakes up to 3g per kilogram for trained individuals, primarily to preserve muscle while in a steep calorie deficit. This is a specific context, not a general recommendation.

Practical Daily Example

A 75kg person training 4 days per week with a goal of building muscle. Target: 1.8g per kg = 135g protein per day.

• Breakfast: 3 eggs plus 150g Greek yogurt = approximately 32g
• Lunch: 150g chicken breast with vegetables = approximately 45g
• Afternoon snack: 1 serve of whey isolate = approximately 27g
• Dinner: 150g salmon plus legumes = approximately 35g

Total: approximately 139g. Target met without a second protein supplement serve and without tracking obsessively. The role of the protein powder here is a single convenience serve that fills the mid-afternoon gap.