Protein: How Much Do You Actually Need?

Nuzest is one of several Protein supplements available to buy at Move Well.

Protein is having a moment. Again.

Walk through almost any supermarket and you’ll find high protein written on everything from yoghurt and cereal to bread, chocolate bars and ice cream. Scroll through fitness or longevity content online and the recommendations become even more confusing:

Eat 0.8 grams per kilogram.

No, eat 1.6.

Actually, make it 2.2

Eat mostly plants.

Prioritise animal protein.

More protein protects muscle as we age.

Less protein may promote longevity.

So, who is right?

The slightly frustrating but scientifically more honest answer is: it depends what you’re trying to achieve.

Where did 0.8 g/kg come from?

For years, approximately 0.8 g of protein per kilogram of bodyweight per day has been quoted as the standard recommendation for adults. That number wasn’t simply plucked from the air. Traditional protein requirements were established largely using nitrogen balance. Protein contains nitrogen, so researchers could compare the nitrogen people consumed with the nitrogen they excreted. The aim was essentially to determine how much protein was required to maintain nitrogen equilibrium.

European guidance currently places the Population Reference Intake at 0.83 g/kg/day for healthy adults (European Food Safety Authority). For a 70 kg person, that’s around 58 g of protein per day. But there is an important distinction here. A population reference intake asks something broadly along the lines of:

How much protein is sufficient to meet the needs of almost all healthy people?

That’s not necessarily the same question as:

How much protein is optimal for me to build muscle, recover from training, retain lean mass while dieting, perform well or age strongly?

And that distinction is where much of today’s protein debate begins.

Then came bodybuilding

Long before protein became synonymous with “health and longevity”, the bodybuilding world had embraced it. Chicken breasts. Tuna. Egg whites. Protein shakes. Six meals a day. And, inevitably, the idea that if protein builds muscle, more protein must build more muscle. Except physiology rarely works in infinitely straight lines.

As exercise nutrition research developed, we started getting a more nuanced picture. For people who train regularly, protein requirements are indeed higher than basic population recommendations. The International Society of Sports Nutrition suggests approximately 1.4–2.0 g/kg/day for most exercising individuals (PubMed Central (PMC)).

But here’s where it gets interesting.

A major meta-analysis examining resistance training found that increasing protein intake helped gains in fat-free mass, but the benefit levelled off at around 1.6 g/kg/day. Beyond approximately 1.62 g/kg/day, additional protein wasn’t associated with further gains in fat-free mass in that analysis (British Journal of Sports Medicine). That doesn’t mean 1.61 g/kg is magical and 1.63 g/kg is wasted. It means there appears to be a diminishing-returns curve. And that’s a much more useful concept than believing that more is always better.

Then protein escaped the gym

More recently, protein has moved out of bodybuilding culture and into mainstream health and longevity. Maintaining muscle matters. It matters for strength and physical independence. It matters for sporting performance. It matters during weight loss. And it becomes increasingly important as we get older and become more susceptible to loss of muscle mass. So we’ve seen another school of thought emerge: don’t merely avoid protein deficiency: deliberately optimise protein intake to preserve muscle throughout life.

At the same time, another branch of longevity science points towards populations that appear to live extraordinarily long lives while eating relatively modest amounts of animal protein. The traditional diets associated with the world’s so-called Blue Zones, for example, tend to be predominantly plant based, with beans and legumes playing a major role and meat eaten relatively infrequently. Researcher Valter Longo similarly advocates a predominantly plant-based/pescatarian approach and relatively modest protein intake earlier in adulthood, while recommending that protein intake increases later in life to help protect against loss of muscle. (fondazionevalterlongo.org).

At the other end of the contemporary longevity conversation are physicians and researchers placing far greater emphasis on maintaining muscle and strength, and therefore advocating substantially higher protein intakes.

Same nutrient.

Different recommendations.

Why?

Because they’re not necessarily asking the same question.

So how much protein should you eat?

Instead of starting with a fashionable number, start with the person.

If you’re generally healthy and relatively sedentary

You probably don’t need to chase enormous protein targets or turn every snack into a protein delivery system. Meeting normal dietary requirements within a varied diet may be perfectly appropriate.

If you’re regularly strength training

Your requirements are likely higher. Somewhere around 1.4–1.6 g/kg/day is a very reasonable evidence-based target for many recreational lifters, with scope to move towards the upper end of approximately 2.2 g/kg depending on the individual, their training and their goals. (PubMed Central (PMC))

If you’re trying to gain muscle

Protein matters, but so do resistance training, sufficient total energy and carbohydrate.

You cannot protein-shake your way around an inadequate training stimulus.

Nor does replacing the carbohydrate required to train hard with ever-increasing quantities of protein necessarily improve your results.

If you’re dieting and trying to retain muscle

Higher protein can become particularly useful. When calories are restricted, adequate protein alongside resistance training can help preserve lean tissue, and higher intakes may be appropriate in some trained individuals during significant energy restriction. (PubMed Central (PMC))

If you’re an endurance or hybrid athlete

This is where we think the current obsession with protein can occasionally become counterproductive. Yes, endurance athletes need protein. But they also need carbohydrate.

If you’re already consuming plenty of protein but consistently under-fuelling your running, cycling, rowing or high-intensity training, adding another 30 g of protein isn’t necessarily the nutritional intervention you need. Protein repairs and remodels tissue. Carbohydrate helps fuel the work. And if performance is your goal, both matter. Current sports nutrition guidance reflects this, recommending higher protein intake for athletes while continuing to emphasise adequate energy and carbohydrate availability. (British Dietetic Association)

Can you eat too much protein?

For a healthy person, protein intakes commonly used in sports nutrition are generally well tolerated. But that doesn’t make unlimited protein inherently beneficial. There is an important difference between:

“Is this amount harmful?”

and

“Is there any advantage to eating this amount?”

Once you’ve consumed enough protein to support your particular goal, increasing it further may offer progressively smaller returns. And food has an opportunity cost.

If protein becomes such a priority that it displaces carbohydrate needed for training, fibre-rich foods, fruit, vegetables, healthy fats or simply enough dietary variety, then a technically “high-protein diet” isn’t automatically a better diet.

There are also circumstances in which generic protein recommendations are inappropriate. People with kidney disease, certain metabolic or medical conditions, or anyone who has been specifically advised to modify protein intake should follow individual medical or dietetic guidance rather than general fitness recommendations. Current chronic kidney disease guidelines, for example, contain specific dietary protein considerations. (KDIGO)

If you have a diagnosed medical condition or you’re unsure whether increasing your protein intake is appropriate, speak to your doctor or a registered dietitian.

The Move Well view

We like protein. We also like carbohydrates. And fats. And vegetables. And eating food because you enjoy it. Nutrition doesn’t become better simply because one macronutrient gets pushed higher and higher.

For somebody lifting weights several times a week, eating 0.8 g/kg of protein may well be less than optimal. For that same person, jumping from 1.6 g/kg to 2.5 g/kg doesn’t automatically mean better results. And for an endurance athlete already consuming adequate protein but struggling to recover from training, the answer may actually be more carbohydrate and more total energy, not another protein shake.

That’s why at Move Well we’re less interested in asking:

“What is the perfect amount of protein?”

and more interested in asking:

“What are you asking your body to do?”

Build muscle?

Lose fat while preserving muscle?

Run a marathon?

Compete?

Recover from injury?

Stay strong as you get older?

Or simply live a healthy, active life?

Because nutrition recommendations only really make sense when they’re attached to a person, a goal and a context. Protein is important. But protein isn’t the goal. Your health, performance and quality of life are.

Co-Founder, Coach and Physiotherapist Kim Johnson