There is about 54g of protein in a chicken breast, 20g in a serving of Greek yoghurt, 18g in a portion of lentils and 12g in two eggs. It seems like, with a healthy, balanced diet, we should be able to get enough without the extra shakes and protein snacks.
"The first thing you need to establish is if you actually need to increase your daily protein intake via a synthetic product such as a protein bar or protein shake or if you can sufficiently hit a protein goal via single ingredient wholefoods," says nutritionist Stuart Jack, despite being the co-founder of the protein supplement brand Musclemary.
Some people need more protein because they are every active, or older," explains nutrition therapist Ian Marber. "Muscle mass reduces as we age and to maintain that we need protein." While some foods with added protein, such as some cereals, can seem like gimmicks, for those who really do have additional needs they can be helpful. "For someone who is older or unwell, who may have reduced appetite, getting fibre and protein in something like Weetabix Protein, which comes with added protein, is a huge bonus for them."
Nutritionist Emma Bardwell, who specialises in perimenopausal and menopausal women's health, also thinks the guidelines are too low for many midlife women. "To optimise health, perimenopausal women should be looking at around 1.2g of protein per kg of body weight, possibly more (1.4-2g) if they work out a lot, have a physically demanding job or have recently been ill. So, a 70kg woman needs approximately 70-100g of protein spread out across the day as we can't break down large amounts (more than 40g) in one go."
Willow Grace Lowry, 51, from Wimbledon, says she started using a protein shake after seeing a nutritionist who recommended she increased her protein to help lose weight. "I found hitting the protein target quite hard with just food – it is possible, but it's a lot of cottage cheese. I find this really helps to fill me up and so I snack less."
Can it help us lose weight?
Weight loss is one of the main reasons people are attracted to added protein. "Due to the thermal effect of feeding, as the body burns a significant proportion of the calories during digestion, and due to its satiating effect, protein keeps individuals fuller for longer and therefore less likely to consume additional calories," says Jack.
Several short-term studies have found that high protein, low carbohydrate diets can help with weight loss, help to preserve lean muscle and satisfy hunger. "I often get clients to start the day with a protein-based breakfast – it can be a game-changer for weight management," Bardwell adds.
But Marber warns that too much protein, without increased exercise, "can be just calories." This is something interior designer Davina Turner, 45, found: "While I was in an intense gym phase and lifting heavy weights, the protein shakes definitely helped; but when I eased off the exercise, I found they were too many calories for my needs."
There are also health risks from overeating protein. "Protein stimulates IGF-1, insulin-like growth factor, which contributes to insulin resistance, cancer and obesity when taken in excess," warns nutritionist Rhian Stephenson. If your diet is already high in processed sugars and excess carbohydrates, too much protein will have a compounding effect. Likewise, the effects of meat are worsened if your diet is lacking in fibre."
Large population studies have suggested a link between high protein intake and an increased risk of diabetes. In addition, a small trial by Washington University School of Medicine found that older women who lost weight on a high protein diet did not see an improvement in insulin sensitivity, which reduces the risk of developing type 2 diabetes.
Another study led by Valter Longo, the director of the Longevity Institute at the University of Southern California, found that midlifers who ate a high protein diet were four times more likely to die of cancer than those who consumed less protein.
Stephenson says that "the more naturally formulated protein shakes can be helpful for individuals who find it incredibly hard to get enough protein in their diets," while Marber says "they may be useful for someone after an intense weight-bearing training session." But, he adds, "for most of us, they aren't necessary. I see average people have done average sessions having a protein shake and for the most part, the majority of it is just extra calories".
Stephenson notes that we need to be mindful about what is in the protein bar or shake. "Many have added sugar syrups or artificial sweeteners, both of which have a cost to our health. While most people understand that consuming excess sugar is harmful to their health, the effects of sweeteners aren't as well known. Studies have shown that artificial sweeteners can negatively impact gut health by damaging the number and diversity of microbes. Many sweeteners can also exacerbate IBS symptoms – they can worsen cramping, bloating and diarrhoea. Even stevia, which is considered the most natural of the sugar substitutes, can still affect the health of our microbiome."
Daniel Lawrenson, 55, started adding in protein bars after his personal training sessions, but soon realised that not all were equal. "I was eating this incredibly delicious peanut butter bar, but when I started looking at the sugar content, I realised that it was really high. I was getting 10g of protein, but about 7g of sugar, too. It was better for me to eat a small bowl of yoghurt," he says.
Then there is the type of protein it's made from. "Whey protein isolate can be particularly bad for digestion," Stephenson says. "If you're going to go for a shake, I would recommend looking for a plant-based source with a blend of hypoallergenic ingredients (like hemp, rice, pea and chia)."
When former Premier League footballer Jermaine Beckford was recommended by club nutritionists to take protein powders, his wife Laura noticed they made him "lethargic and gave him digestive problems every day". They decided to develop their own, plant-based supplement, Supernova. "A lot of cows are pumped with growth hormones, antibiotics and drugs. We wanted pure, effective ingredients so chose organic pea, organic brown rice and golden chlorella as our plant protein base, which are the most digestible, sustainable sources of protein and contain a full amino acid profile."
Stephenson warns that even plant proteins can have downsides. "Many have been shown to have higher levels of heavy metals and environmental toxins," she says.
The need for quality applies to wholefoods, too. "High amounts of poor quality processed and factory-farmed meats are definitely bad for health, too," she says. Organic, grass-fed, pasture-raised meat is the best source of protein. "Historically it's been harder to find, but farm to table delivery companies such as Fosse Meadows, Piper Farms and Riverford are making good quality meats more readily available at a much more reasonable price."
So the advice is not clear cut on whether we do all need more protein, and if it will improve – or harm – our health. But Stephenson has a final word of advice. "The bottom line is keep it simple, opt for real food sources first and if you do use a replacement, get a high-quality one and use it sparingly."