How Much Protein Do I Need Per Day?

The amount of protein you need each day depends on your body weight, age, and goals. The widely cited recommendation of 0.8 g per kg is the bare minimum for survival — not the optimal amount for health, muscle maintenance, or fat loss. This guide explains exactly how much protein you actually need.

Quick Reference — Protein Needs by Goal

Why the Standard 0.8 g/kg Recommendation Is Too Low

The recommended dietary allowance (RDA) for protein is 0.8 g per kilogram of body weight per day. This figure is widely cited on food packaging, in government guidelines, and by general practitioners. But it is frequently misunderstood.

The RDA is defined as the minimum amount needed to prevent deficiency in 97.5% of the sedentary population — not the optimal amount for health, performance, or body composition. For most people with any health or fitness goal, 0.8 g/kg is a floor, not a target.

Multiple systematic reviews and meta-analyses have found that protein intakes of 1.6–2.2 g/kg per day produce significantly better outcomes for muscle retention, fat loss, satiety, and metabolic health in active adults compared to the RDA.

How Much Protein You Need — By Goal

For General Health and Sedentary Adults

If you do not exercise regularly and have no specific body composition goals, the RDA of 0.8 g/kg is an adequate minimum. A slightly higher intake of 1.0–1.2 g/kg is preferable as it provides a buffer against age-related muscle loss (sarcopenia) and supports immune function, enzyme production, and tissue repair.

For People Who Exercise Regularly

Exercise — particularly resistance training — increases the rate of muscle protein synthesis and breakdown. To support net muscle retention and recovery, active adults need significantly more protein than the RDA. The current evidence-based recommendation for active adults is 1.4–1.8 g/kg per day.

For Fat Loss

This is when protein intake matters most. During a calorie deficit, the body is at risk of breaking down muscle tissue for energy — a process called catabolism. High protein intake is the primary defence against muscle loss during fat loss.

Research supports 1.8–2.4 g/kg per day during active fat loss phases, with some studies suggesting even higher intakes (up to 3.1 g/kg) may be beneficial for lean athletes cutting weight. For most people, 2.0–2.2 g/kg is a practical and effective target.

For Muscle Building

The relationship between protein intake and muscle gain plateaus at approximately 1.6–2.2 g/kg per day for most people. Consuming more than this does not produce additional muscle gain — excess protein is simply used for energy. The key variables for muscle growth beyond protein are total calorie surplus, training volume, and sleep.

For Older Adults (Over 65)

Ageing reduces the sensitivity of muscle to protein — a phenomenon called “anabolic resistance.” Older adults need more dietary protein than younger adults to achieve the same muscle protein synthesis response. The current recommendation for adults over 65 is 1.2–1.6 g/kg per day as a minimum, with active older adults benefiting from 1.6–2.0 g/kg.

Adequate protein intake in older adults is strongly associated with reduced risk of sarcopenia, falls, fractures, and functional decline.

Protein Requirements by Body Weight

Here are practical daily protein targets across different body weights for the most common goals:

Best High-Protein Foods

Meeting a daily target of 120–160 g protein requires choosing protein-rich foods consistently. Here are the most efficient sources ranked by protein per 100 g:

Timing — Does When You Eat Protein Matter?

Protein timing is less important than total daily protein intake — but it is not irrelevant. Current evidence supports the following:

• Spread protein across 3–5 meals — muscle protein synthesis is maximised with doses of 20–40 g per meal. Eating all your protein in one meal is significantly less effective than spreading it throughout the day.
• Pre- and post-workout protein — consuming protein within a few hours of training (either before or after) supports muscle protein synthesis. The “anabolic window” is not as narrow as once believed — eating within 2–3 hours either side of training is sufficient.
• Protein before bed — 30–40 g of slow-digesting protein (casein, cottage cheese, Greek yoghurt) before sleep has been shown to support overnight muscle protein synthesis and improve next-day recovery.

Plant vs Animal Protein — Does the Source Matter?

Animal proteins (meat, fish, eggs, dairy) are generally considered “complete” proteins — they contain all nine essential amino acids in adequate proportions. Plant proteins are often “incomplete” — they are low in one or more essential amino acids.

However, this does not mean plant-based diets cannot meet protein needs. People following plant-based diets should:

• Eat a variety of protein sources — combining complementary plant proteins (e.g. rice and beans, hummus and bread) provides all essential amino acids over the course of the day
• Target slightly higher protein intake — plant proteins have lower digestibility than animal proteins. A 10–20% higher total intake compensates for this difference
• Consider leucine-rich sources — leucine is the amino acid most directly responsible for triggering muscle protein synthesis. Soy, edamame, lentils, and hemp seeds are among the best plant sources

Is Too Much Protein Harmful?

For healthy adults with normal kidney function, there is no evidence that high protein intakes (up to 3.5 g/kg per day) cause harm. The concern that high protein damages kidneys applies to people with pre-existing kidney disease — in whom protein restriction may indeed be advised — but does not apply to healthy individuals.

The practical upper limit for most people is set by calorie budget rather than safety — at 4 kcal per gram, very high protein intakes leave little room for carbohydrates and fat at typical calorie targets.

Frequently Asked Questions

The Bottom Line

The government RDA of 0.8 g protein per kg per day is a minimum, not an optimal target. For most active adults, 1.4–2.2 g/kg per day produces significantly better outcomes for muscle mass, fat loss, satiety, and metabolic health.

Set your protein target based on your body weight and goal — fat loss requires the most protein (1.8–2.4 g/kg), muscle building needs 1.6–2.2 g/kg, and general health in active adults is well served by 1.4–1.8 g/kg. Spread intake across 3–5 meals, prioritise complete protein sources, and adjust based on real-world progress.