This is how much protein you actually need – it's more than you think
How much protein do you actually need to eat every day? And why does protein matter anyway? Apart from the fact that protein is the building block of muscle, and it supports sustainable weight loss and longevity – there’s much more to this macro than you realise...
‘Muscle strength, performance and metabolic balance,’ says Lauren Kanski, PT and founding coach for fitness app Ladder, reeling off the benefits of a diet high in protein.
She’s not done. ‘It’s also the most satiating macro,’ she tells us, adding that eating the right amount and improving your muscle health can help lower your blood pressure and blood sugar, as well as strengthen your immune function.
How much protein do I need?
And yet, hitting your RDA (recommended daily allowance) of protein – that’s 0.75g per kilogram of body weight – isn’t quite as easy as eating more chicken, especially if you want to ensure a balanced, nutrient-dense diet.
How much protein do I need? According to the NHS, most adults need around 0.75g of protein per kilo of body weight per day – for the average woman, this is around 45g, which is roughly two portions of meat, fish, nuts or tofu per day.
The best protein sources – fish, lean meats, dairy, beans – may not seem as quick and easy to add to your day as carbs. Then there’s the fact that a growing number of dietitians believe the current guidelines to be too low.
‘[The RDA] is just a baseline,’ says Kristen Smith, spokesperson for the Academy of Nutrition and Dietetics in the US. ‘It’s the minimum amount you need to eat daily to stay healthy but doesn’t take into account specific goals or medical conditions,’ she says.
Most researchers are now saying we need more like 1.1g to 1.5g per kilogram in order to support tissue growth – especially if you exercise regularly.
‘There’s evidence to suggest protein intakes over the RNI can help to preserve muscle mass during dieting, and for those regularly strength training, higher protein intakes (1.2g to 1.6g per kilo) help with muscle growth and recovery,’ says dietitian Laura Tilt.
Indeed, a Johns Hopkins University study found that a diet in which roughly a quarter of the calories (about 60% more than the recommended 10% to 15%) come from lean protein sources reduced blood pressure, LDL (‘bad’) cholesterol levels and triglycerides better than traditional higher-carb diets. Other research has found that eating plenty of protein can help prevent obesity, osteoporosis and diabetes.
How much protein do I need to lose weight?
Seeing as high-protein foods are often more calorie-dense than many carbs, such as fruit and vegetables, you might consider it counterintuitive to place them at the heart of a sustainable weight-loss strategy. However, they take a lot more work to digest, metabolise
and convert to energy. They also take more time to leave your stomach, meaning you become full sooner and stay that way for longer.
The cumulative effect has several obvious benefits for anyone looking to reach a healthy weight range. According to a study published in the American Journal Of Clinical Nutrition, dieters who increased their protein intake to 30% of their diet ate nearly 450 fewer calories a day and lost about 11lb over the course of 12 weeks, without deploying any other dietary measures.
Your body uses the amino acids in protein to build lean muscle, which not only makes you stronger, but also burns calories even when you’re not active. Ultimately, this keeps your metabolism humming along at high speed all day.
How much protein is too much protein?
Can you have too much of a good thing? Tilt thinks so. ‘The problem comes in thinking that because some protein is good, lots must be better. Studies have shown that consuming over 2g per kilo of body weight brings little benefit when it comes to building muscle,’ she says.
Given that there’s no storage facility for protein, eating more than you need means the surplus will be used for energy – but if you consume more calories than you expend trying to get your protein fix, then the excess can be stored as fat.
What you need to consider is what all that protein is replacing, she adds. ‘Ditching whole grains for a protein-heavy salad at lunch means you'll be consuming less fibre, which fosters a healthy microbiome and ensures a good southbound service. Excessive intakes of protein can also result in some protein escaping into the colon, potentially feeding less favourable bacteria.’
What have amino acids got to do with it?
There’s so much more to protein than boosting metabolism and building muscle – and an understanding of why begins with amino acids.
‘[They’re] the building blocks of life,’ says Cara Harbstreet, a dietitian and owner of Street Smart Nutrition.
Humans need amino acids to perform essential functions, she explains; they help mount a response to infection, are needed for just about every structure in the body – your bones, liver, gut, tissue, hair, nails, skin – and act as enzymes, hormones, buffers, transporters and regulators.
Over the past two decades, researchers have come to understand that skeletal muscles are endocrine organs, just like the thyroid. During muscle contraction, they produce and secrete myokines: small proteins that can keep inflammation from getting out of hand. This is also why being under-muscled is fast becoming a health problem to watch out for.
But the conversation isn’t about how much (or little) you can deadlift. Patients with less muscle mass have more complications in surgery and post-operation, longer hospital stays and lower survival rates, according to an Annals Of Medicine review of more than 140 studies. That ageing bodies process protein less efficiently means they need more of it to maintain muscle strength, bone health and other functions, too.
‘People tend to only think of muscle and protein in relation to fitness and that’s a mistake,’ says Gabrielle Lyon, the founder of the platform Muscle-Centric Medicine, who believes we should all be thinking of muscle as a healthy ageing strategy. And one way to do that is by focusing on high-quality protein.
‘Humans can synthesise, or create, some of the amino acids needed to build complex proteins,’ adds Harbstreet. ‘But must source [the ones] we can’t make from our diets. Eating a variety of plant- and animal-based foods can ensure you get enough total protein as well as sources for all essential amino acids.’
How to hit your protein goals
Of course, most of us don’t really have the time or energy to meticulously count out and calculate our macros for every meal of the day. An easier way to hit your target? Aim for about 20g to 25g per meal.
The ‘per meal’ language is intentional; your body doesn’t store amino acids in the same way it does with carbs (as glycogen) and fat (body fat), so you really do need to eat it all day long.
Studies also show that spreading out protein intake into moderate doses every three to four hours or so versus gobbling it down all at once is associated with more optimal muscle repair – and for those looking for muscle growth, it’s more optimal for that, too.
As for the 20g to 25g goal, research indicates that this is the amount of protein the body can use for muscle synthesis at one time.
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