Type "how much protein do I need" into a search engine and you'll get answers ranging from 50g to 300g per day, depending on who's talking and what they're selling.
Fitness influencers will tell you to eat your bodyweight in grams. Supplement brands will suggest you need protein shakes three times a day. Government guidelines feel cautiously low. And your mate at the gym swears he needs 200g a day minimum or his muscles will evaporate.
The actual answer, supported by decades of research, is far more measured than any of these.
The Evidence-Based Range
For most adults, the current evidence-based recommendations on protein intake fall into two broad categories.
For the general population, the UK Reference Nutrient Intake is 0.75g of protein per kilogram of body weight per day. For an 80kg person, that's 60g. This is the amount considered sufficient to meet the needs of most of the population and prevent deficiency. It's a minimum, not an optimum.
For active adults — anyone doing regular resistance training, endurance exercise, or physically demanding work — the International Society of Sports Nutrition recommends 1.6g to 2.2g per kilogram of body weight per day. For an 80kg person, that's 128g to 176g.
This range is supported by a 2018 meta-analysis published in the British Journal of Sports Medicine, which analysed 49 studies and found that protein supplementation significantly augmented muscle mass and strength gains from resistance training, with the most pronounced benefits generally seen around intakes of approximately 1.6g/kg/day, with diminishing returns beyond that.
What That Looks Like In Real Life
Let's make this practical. For an 80kg person aiming for 1.6g per kilogram:
Daily target: 128g protein
A realistic day of eating might look like this:
Breakfast — Two eggs on toast: approximately 20g protein.
Mid-morning — One serving of Protein & Fibre: 21–23g protein.
Lunch — Chicken breast with rice and vegetables: approximately 35g protein.
Afternoon snack — Greek yoghurt with seeds: approximately 15g protein.
Dinner — Salmon with potatoes and salad: approximately 30g protein.
Total: approximately 123–125g protein.
That's within striking distance of the target without obsessing over every gram. One protein shake, three regular meals, and a snack. No complicated supplementation protocol. No eating chicken breast out of tupperware six times a day.
For someone aiming at 2.0g/kg (160g), you might add a second serving of Protein & Fibre or increase portion sizes slightly at meals. It's achievable without restructuring your entire life.
The "More Is Always Better" Myth
There's a persistent belief in fitness circles that if 1.6g/kg is good, then 3g/kg must be better. The logic seems intuitive, but the evidence doesn't support it.
Research consistently shows that beyond approximately 2.2g/kg per day, additional protein intake does not produce meaningful further gains in muscle mass or strength. Your body has a limited capacity to use protein for muscle synthesis at any given time. Excess protein beyond what your body can use is either used for energy or processed and excreted by the body — it doesn't get stored as extra muscle.
This doesn't mean higher protein intakes are harmful for healthy individuals. They're simply unnecessary. You're spending money on protein your body can't use for its intended purpose.
The exception is during periods of significant caloric deficit, where slightly higher protein intakes (up to 2.4g/kg in some studies) may help preserve muscle mass during weight loss. But this is a specific context, not a general recommendation.
The Protein Quality Question
Not all protein is created equal. The quality of your protein source matters, and two factors are particularly relevant.
Amino acid profile. Your body needs all nine essential amino acids to effectively synthesise muscle protein. If your protein source is missing or low in one or more of these, your body's ability to use that protein is limited by the least available amino acid.
Complete proteins contain all essential amino acids in adequate proportions. Most animal proteins are complete. Among plant proteins, the picture varies — pea protein is low in methionine, rice protein is low in lysine, and hemp protein is often limiting in several essential amino acids.
Sunflower kernel protein contains all nine essential amino acids, including the branched-chain amino acids leucine, isoleucine, and valine. It's naturally complete without needing to blend multiple protein sources.
Digestibility. How efficiently your body can extract and use the protein also matters. Highly processed isolates may score well on rapid digestibility metrics, but the clinical significance of these differences in the context of a normal mixed diet is modest. When you're eating protein across multiple meals from various sources, small differences in digestibility between individual sources become largely irrelevant.
Common Misconceptions
"I need protein immediately after training." The anabolic window is much wider than the supplement industry suggests. Having protein within a few hours of training is sensible, but the frantic 30-minute rush isn't supported by current evidence. Total daily intake matters far more than precise timing.
"I can't get enough protein without supplements." Most people can meet their protein needs through food alone. A protein shake is a convenient way to fill gaps, especially for active individuals with higher requirements, but it's not strictly necessary if your diet is well planned.
"Plant protein isn't as effective as whey." When total protein intake and amino acid profiles are comparable, research suggests similar outcomes for muscle building between plant and animal protein sources. The key is consistency and adequacy, not the specific source.
"I should have protein with every meal." Distributing protein across the day is modestly beneficial, but missing protein at one meal doesn't undo your nutrition. A generally consistent approach is more important than rigid meal-by-meal targets.
Where Protein & Fibre Fits In
A single serving of Protein & Fibre provides 21–23g of complete protein. That's a meaningful contribution to your daily target — roughly 15–18% of a 128g daily goal, or the equivalent of a chicken breast.
The difference is what comes alongside it. Each serving also delivers 8–10g of fibre (roughly a third of the recommended 30g daily intake), healthy fats, and naturally occurring vitamins and minerals. You're not just hitting a protein number — you're contributing to your overall nutritional balance.
It fits wherever you need it. Mid-morning between breakfast and lunch. Post-workout when you want something quick and easy. As a protein boost alongside a lighter meal. There's no single "right" time to have it, because protein timing is far less important than protein consistency.
The Simple Version
For most active adults: aim for 1.6g to 2.2g of protein per kilogram of body weight per day. Spread it across your meals. Choose complete protein sources with good amino acid profiles. Don't obsess over timing. Don't pay for significantly more protein than your body is likely to use effectively.
And if a protein shake helps you hit your target conveniently, make sure it's giving you more than just protein. Because the difference between a stripped-down isolate and a whole-food protein is the difference between a number on a spreadsheet and actual nutrition.
Frequently Asked Questions
How much protein do I need if I'm not very active?
The UK Reference Nutrient Intake for sedentary adults is 0.75g per kilogram of body weight per day. However, many nutritionists suggest slightly higher intakes of 1.0–1.2g/kg may better support muscle maintenance, satiety, and overall health, particularly as you get older.
Can I eat too much protein?
For healthy adults, high protein intakes (up to about 2.2g/kg/day) are well tolerated. Beyond this, additional protein provides diminishing returns for muscle building. There's no strong evidence that moderately high protein intakes harm healthy kidneys, but those with pre-existing kidney conditions should follow medical guidance.
Is 21–23g of protein per shake enough?
Yes. 21–23g is a substantial protein serving, comparable to a chicken breast or three eggs. Combined with protein from your regular meals, it contributes meaningfully to a daily intake of 1.6–2.2g/kg for most people.
Do older adults need more protein?
Research suggests older adults may benefit from protein intakes at the higher end of the recommended range (1.2–1.6g/kg/day or more) to help counteract age-related muscle loss. Consistent daily protein intake becomes increasingly important with age.
Does the type of protein matter for muscle building?
The amino acid profile and your total daily intake are the primary factors. Complete proteins with adequate leucine content support muscle protein synthesis most effectively. Sunflower kernel protein provides a naturally complete amino acid profile with all essential amino acids, including BCAAs.