Why everything you know about protein is wrong

Neil Perry's beef sticks slicked with spicy tamarind marinade.
Neil Perry's beef sticks slicked with spicy tamarind marinade. Photo: William Meppem

Bars, bagels, sparkling water, spread: protein is everywhere, but not as you know it. What was once considered a staple component of chicken, fish and eggs has become the healthy eating marketer's holy grail.

From bags of nuts to sacks of potatoes, run-of-the-mill groceries now come with a "high protein" sticker, in spite of the ingredients being the same as before, while others - cereals, chocolate bars and bread - see additional amounts inserted artificially, and supermarket shelves carry an ever-expanding range of products, from shakes to protein powerballs specifically designed to pack in an extra hit.

Neil Perry's spiced lamb with zucchini.
Neil Perry's spiced lamb with zucchini. Photo: William Meppem

With the promise of assisting weight loss and building muscle, our obsession to capitalise on this health "saviour" means that consumption now far exceeds demand. The average adult needs 0.75 grams of protein daily for every kilogram they weigh; so a person weighing 70kg should be eating 52.5geach day - equivalent to a large bowl of oats, three eggs and a chicken breast. Yet the current average daily rate of consumption in Britain among people aged 19-64 is now 72g.

Alongside fat and carbohydrates, protein is one of the three macronutrients our bodies require in relatively large amounts. It is "vital to the crucial and ongoing building, strengthening and repairing of muscle, bone, skin, hair and major organs, as well as being an essential component of enzymes, hormones and antibodies", says James Collins, nutritionist and author of The Energy Plan.

Proteins are amino acids, many of which are produced naturally by the body, but nine essential ones are not, and so must be taken from food. Of those, there are complete proteins, such as meat and fish, cheese and quinoa, and incomplete, such as nuts and pulses, which require being combined with others (baked beans on wholegrain toast, for example) in order for the full benefits to be realised.

It is really important to remember that carbs and protein have exactly the same amount of calories per gram.

Dietitian Sophie Medlin

Our appetite for the stuff has skyrocketed: about half of all British consumers now seek to add extra protein to their diets, according to Weetabix - which offers a protein-enhanced version of its cereal, costing an additional 50p per box - while the number of products carrying a "high protein" claim on their branding shot up by 498 per cent between 2010-15, according to Mintel research.

At health retailer Holland & Barrett, there has been a 15 per cent increase in sales of protein products sold in the first half of this financial year compared to the last. So why is this happening, and how much is too much?

In a world where "muscly is the new skinny", dietitian Sophie Medlin says, "protein has become the least feared macronutrient". It's not just bodybuilders wanting to bulk up who have fallen for its charms: low-carbohydrate diets such as keto and paleo, which largely consist of high-fat, high-protein foods, have helped drive this newfound affection, along with celebrities and magazines who advocate shunning bread and pasta.

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People's "trust" in protein to not cause weight gain is "a by-product of the misconception that carbs make us fat", Medlin adds. "It is really important to remember that carbs and protein have exactly the same amount of calories per gram (4kcal). This means that they have the same impact on our energy intake."

When it comes to diets, misinformation is common, says David L Katz, a doctor and author of The Truth About Food. Where "most people know that if something sounds too good to be true, it is", this logic fails to apply to food, a realm in which we are "perennial nincompoops" and "always seem to need a silver bullet. At the moment, protein is the silver bullet." Some of this is driven by sites such as Instagram, Medlin adds, which is "terrifying", particularly for those younger and potentially more easily swayed, "when we look at the recent evidence that social media influencers dish out false nutrition claims 90 per cent of the time".

She suggests the creation of a verification symbol for registered healthcare professionals, who are legally accountable for the advice they give online - a way of combating the self-professed "plant-based doctors" and "low-carb doctors" that have gained an enormous digital following.

"In reality, a healthy, balanced diet contains all food groups in moderation. Unfortunately, moderation is a message that doesn't sell books or gain headlines," Medlin says.

There are plenty of people for whom pre-internet wisdom prevails, with the likes of the Atkins diet popularising protein-high, low-carb diets since the '70s. For some, it works - weight loss-wise, at least - yet the effects of eating too much can be injurious.

A protein overload can put added pressure on the kidneys, which are responsible for breaking down the excess, and can be particularly damaging for those with pre-existing conditions. Studies show that eating lots of red meat and full-fat dairy, which diets like keto and paleo espouse, are associated with higher risk of health issues such as cancer and heart disease, while Finnish research found that men who ate an average of 109g of protein each day were 33 per cent more likely to have heart failure than those who ate 78g.

There is also the mistaken belief that, because protein is good for us, there is no such thing as too much.

The notion that "the more you eat, the better" is a "critical fallacy", Katz explains, as eating too much of anything - protein included - sees "those calories turn into body fat". People are wrongly convinced, he adds, that when extra energy comes from protein they turn to muscle. "That's completely false. Calories you don't need are stored [as] glycogen (our carbohydrate store) or fat."

The promise of more muscle has become big business for the protein-pushers, but shovelling down endless shakes or bars does not work; the only way to bulk is through exercise.

A 2010 study by the European Food Safety Authority found claims purporting that whey protein boosted muscle mass in the general population were unfounded.

"Using 'protein' as a marketing term for a highly processed food so that consumers think it is healthy is misleading and irresponsible," Medlin says. "Instead of protein shakes, which are highly processed, a yoghurt would be far preferable."

For building muscle, it is more of a case of when, as opposed to how much, protein is consumed. Collins says that eating a good source of it within 24 hours of resistance training, such as lifting weights, has notable effects, while a study found that spreading protein doses through the day, rather than in one large meal, can serve our bodies best.

And while it is often the young, hard-bodied types who obsess over getting enough, it is in fact older people who have the greatest need to stay on top of their protein consumption, as muscle mass diminishes with age.

As the vegan dawn spreads apace, the focus on the environmental impact of what we're eating has become more acute, too. Katz, who co-authored 'The Public Health Case for Modernising the Definition of Protein Quality' in the journal Advances in Nutrition this month, proposes that we start considering "quality" protein not in terms of foods with the largest amount of it, but those that "contribute to better health, and to the environment".

Our protein obsession remains "at odds with everything we know about health [and] everything we know about the planet", Katz adds.

Whether that message will filter through to the shake-swigging masses, though, remains to be seen.

The Telegraph, London