How much protein do you actually need?

The protein question

Protein is one of the most discussed nutrients in health and fitness. From gym-goers trying to build muscle to older adults aiming to maintain strength, understanding your protein needs is crucial. But with so much conflicting advice, what does the evidence actually say?

What protein does for your body

Protein isn't just about muscle. It's involved in:

• Building and repairing tissue: Muscles, skin, hair, nails, and organs
• Enzyme production: Essential for digestion and metabolism
• Hormone synthesis: Including insulin and growth hormone
• Immune function: Antibodies are made from protein
• Satiety: Protein keeps you feeling full longer than carbs or fat

The official recommendations

The UK Reference Nutrient Intake (RNI) for protein is 0.75g per kilogram of bodyweight per day for adults. For a 70kg person, that's 52.5g daily.

However, research suggests these figures may be too conservative, particularly for:

• People who exercise regularly
• Older adults (over 65)
• Those trying to lose weight
• Anyone recovering from illness or injury

Evidence-based recommendations by goal

For general health

Recommendation: 0.8-1.0g per kg of bodyweight

If you're moderately active and just want to maintain good health, aiming for 0.8-1.0g per kg is sensible. For our 70kg example, that's 56-70g daily.

For muscle building

Recommendation: 1.6-2.2g per kg of bodyweight

Multiple studies have shown that higher protein intakes support muscle protein synthesis when combined with resistance training. A landmark 2018 meta-analysis found no significant benefits above 1.6g/kg, though some individuals may benefit from up to 2.2g/kg.

For our 70kg person: 112-154g daily.

For fat loss

Recommendation: 1.6-2.4g per kg of bodyweight

When in a calorie deficit, higher protein intake helps preserve muscle mass and increases satiety. Some research suggests going even higher (up to 2.4g/kg) during aggressive diets.

For older adults (65+)

Recommendation: 1.0-1.2g per kg of bodyweight

Age-related muscle loss (sarcopenia) is a significant health concern. Higher protein intakes help preserve muscle mass and function in older adults.

Protein timing: does it matter?

The "anabolic window" myth has been largely debunked. While there may be some benefit to consuming protein around your workout, total daily intake matters far more than precise timing.

That said, spreading protein across meals (20-40g per meal) may be more beneficial than consuming it all at once, as there's a limit to how much protein can be used for muscle protein synthesis at one time.

Best protein sources

Complete proteins (contain all essential amino acids)

• Chicken and turkey
• Fish and seafood
• Eggs
• Dairy (milk, yoghurt, cheese)
• Soy products (tofu, tempeh, edamame)

Plant proteins (combine for complete amino acid profile)

• Legumes (beans, lentils, chickpeas)
• Nuts and seeds
• Whole grains (quinoa is complete)
• Vegetables (smaller amounts)

Practical tips

1. Include protein at every meal: Aim for 20-40g per sitting
2. Don't neglect breakfast: It's often the lowest-protein meal
3. Snack smartly: Greek yoghurt, nuts, or a protein shake
4. Read labels: Some "high protein" products aren't that impressive
5. Prioritise whole foods: Supplements are convenient, but real food is better

What about protein supplements?

Protein powders can be useful for convenience but aren't necessary if you can meet your needs through food. If you do use them:

• Whey protein: Fast-absorbing, high in leucine, great post-workout
• Casein: Slow-absorbing, good before bed
• Plant proteins: Pea, rice, or blends for vegans/vegetarians

Common concerns

"Will high protein damage my kidneys?"

For healthy individuals, there's no evidence that high protein intake harms kidney function. However, if you have existing kidney disease, consult your doctor before significantly increasing protein.

"Will too much protein make me bulky?"

No. Building significant muscle requires consistent resistance training and often years of dedicated effort. Eating more protein alone won't make you bulky.

"Is animal or plant protein better?"

Both can support health and fitness goals. Animal proteins are typically more complete and bioavailable, but well-planned plant-based diets can absolutely meet protein needs.

Calculating your needs

1. Determine your weight in kilograms
2. Choose the appropriate multiplier for your goal
3. Multiply to get your daily target

Example: 70kg person wanting to build muscle 70 × 1.6 = 112g minimum 70 × 2.2 = 154g maximum

Aim for somewhere in this range, adjusting based on results and how you feel.

Summary

• Official recommendations may be too low for active individuals
• 1.6-2.2g/kg is well-supported for muscle building
• Spread intake across meals for optimal use
• Whole food sources should be prioritised
• Supplements are convenient but not essential

References

1. Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018.
2. Phillips SM, Van Loon LJ. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci. 2011.
3. Bauer J, et al. Evidence-based recommendations for optimal dietary protein intake in older people. J Am Med Dir Assoc. 2013.