Do I really need to eat more protein?

Unlike fat and carbohydrates, protein has a saintly reputation –  but do the experts agree?

Protein is one of the big three nutrient groups the body needs to function properly – together with fats and carbohydrates, they form the basis of a healthy diet.

It’s the main component of our muscle fibres, and is vital for a functioning heart, immune system and endocrine system – and it’s also a vital energy source.

There’s no argument that we all need protein in our diets, but there is confusion about how much we should be eating on a daily basis. The i Paper talks to the experts.

How to get the right amount in a day

NHS guidelines recommend around 0.75g to 0.8g per kilogramme of bodyweight per day – that’s around 64g a day for an average man, or 55g for a woman.

This is the equivalent to eating 40g of oats (5g of protein) one 100g greek yoghurt (10g), two medium eggs (12g), two slices of wholewheat toast (8g) and one chicken breast (30g) – this totals 65g protein.

These are the requirements you need “in order to not be deficient”, says Adam Collins, associate professor of nutrition at the University of Surrey, “and if you look at typical intakes of protein, people are eating about 50 per cent more than that, by about 1.1g to 1.2g per kilogramme per day.” This is why dietitians will often say that in the Western world nobody needs more protein.

However, “there is an argument to say that we are being too conservative with our nutritional reference values,” he adds.

There are many more moving parts that determine what is closer to an optimum protein intake for an individual person – firstly, the source and quality of the protein they’re eating.

Do I need more protein if I’m vegan or vegetarian?

Dietary protein can come from both animal and plant-based sources, though the animal sources are more likely to be “complete” proteins, where the molecule has all the essential amino acids. This means they are better at helping you repair and build tissues, says Dr Collins. However, you can combine different plant protein sources to make sure you get all your essential amino acids – for example pea and rice protein.

People on more plant-based diets, therefore, will have to eat a greater variety of sources of protein to make sure they’re getting all their required amino acids. To get the equivalent protein as the omnivore above, you would need to eat: 40g of oats (5g of protein), 100g plain soy yoghurt (6g), two tablespoons of peanut butter (7g), two tablespoons of chia seeds (10g), 100g of whole grain rice (6g), half a tin of black beans (8g), two handfuls of mixed nuts (10g), one portion of quinoa (4.4g), one tablespoon hemp seeds (5g) and one slice of wholemeal toast (4g).

They may also need to eat slightly more protein in total, says Dr Collins, as the body can’t absorb as much from plant sources as from animal ones, but the discrepancy is not huge.

What if I’m building muscle – or losing weight?

If you want to gain weight, gain muscle, or just get stronger, dramatically increasing your protein intake is recommended. It makes sense that if you want to build body protein, you need to supply it in dietary form.

“If you want to build muscle, you probably need more than your baseline level of protein in order to supply that increase in body protein that you’re trying for. So that might go up to 1.2g or 1.5g per kilogramme of bodyweight, or maybe even more,” says Dr Collins.

This is not just for those who are lifting heavy weights: “If you’re doing a lot of exercise generally, your protein requirements may be slightly higher as a consequence.” Crucially though, he says that consuming protein isn’t going to equal muscle gains on its own: “You also need to trigger the muscle to build that protein. That’s where any form of resistance exercise comes in.”

Meanwhile, people who are trying to lose weight may also have a higher level of optimum protein. Dr Oliver Witard, of King’s College, London, says that there is some evidence higher protein intake is beneficial for people looking to lose weight.

“If an individual wants to lose weight then of course what they want to lose is fat – not muscle. So during weight loss there is evidence that you need to elevate protein,” adds Whitard a reader in exercise metabolism and nutrition at KCL’s Faculty of Life Sciences and Medicine.

Protein is also proven to help with weight loss because it keeps you fuller for longer than carbs.

In that vein, as we age, our muscles lose their ability to use protein as effectively, particularly for post-menopausal women. So a protein increase in your later years can be beneficial as you need more to be able to stimulate the muscles to the same extent.

“Beyond the age of 60 to 65, you might need to increase your protein intake,” Dr Collins says. “There’s only so much you can cope with though, because sometimes you’ve got gastric insufficiency where you can’t eat 100 grams of protein in one sitting.” In all cases, they recommend eating a bit more protein throughout the day in smaller increments, but this must, again, be coupled with physical activity.

Can protein ever be unhealthy?

Unlike the other macronutrients (carbohydrates and fats) protein has a pretty spotless reputation: fat and carbs have both been lambasted as the cause of metabolic diseases and weight problems, but protein has avoided that label. As such, people will happily recommend huge increases in protein for anyone. You only need to look on the supermarket shelves to see the protein label on endless products, including supplements.

“Protein is seen as an almost magic macronutrient that is different to fats and carbohydrates, and to some extent that’s true, says Dr Collins. “But if you eat more protein than you need, it is going to end up turning into sugar which drives fat storage. In a roundabout way, a calorie is still a calorie, whether it comes from fat, carbohydrate, protein or alcohol.”

Remember too that the source of the protein you’re eating is all-important. It’s no good meeting your target through just sausages or cheese – as these will raise levels of saturated fat intake. So quality, rather than quantity, is a better protein-related goal

In general, wholefood sources are nutritionally preferred: lean meats, poultry, fish, eggs, dairy, beans, lentils and nuts. In contrast, many protein bars and drinks are UPFs (ultra-processed foods) and may have hidden sugar, salt and fat.

Research by Dr Witard has also shown there’s only a certain amount of protein your muscles can use.

“Our muscles are only able to utilise, on a per-serving basis, somewhere between 20g and 30g of protein in a given dose, before – rather than it being incorporated into new muscle – it gets either excreted in the urine or it gets oxidised over a three or four-hour period. Those studies lend themselves to the idea that more is not necessarily better, and that there’s only so much you can utilise from a physiological perspective.”

With this in mind, it’s far better to have protein in steady, incremental doses throughout the day than have a huge quantity of protein at once.

He says that the idea of focusing heavily on your protein intake is “misguided messaging” – because it’s ineffective at achieving your health goals, rather than because it is dangerous: “High protein diets are only dangerous if you’ve got underlying kidney issues or if you’re on dialysis for example.”

Dr Collins summarises it this way: “Protein is good and you should have some every meal, but you can still have too much of it. If you’re very active, or you’re older, then there could be reasons why you need to make sure you’ve got adequate amounts, and maybe a bit more than the typical intake. But there’s no need to aggressively over consume protein or make sure we get protein all the time.”