A high-protein diet can boost fitness as well as help us maintain muscle in later life

Exactly how much protein should midlifers be consuming?

I’m a late-life gym bunny. At the age of 59, you’ll find me at Pilates, barre, yoga or using the weight machines at my gym most days. But I’m still not as toned as I’d like and a recent test revealed I’d made little progress in building muscle and strength over six months.

Why? The answer could lie with my diet. More specifically, in the lack of protein. It turns out it’s much harder to build muscle mass and strength without consuming adequate protein. And as we age, we may need more than we think.

After the age of 30, we lose 3-8 per cent of our muscle mass every decade, and this rate of decline is more rapid after 60. What’s more, from the age of 50, muscle quality and strength also decline. This can eventually cause a muscle-weakness condition called sarcopenia, which is a risk factor for frailty and falls. It can occur as early as 65 and affects most people to some degree by the age of 75, especially if we are inactive.

Eating more protein can also help prevent midlife spread. As a recent study showed, people ate 210 calories more per day than when they were on a low-protein diet. “The more muscle you have, the higher your metabolism,” says Kim Pearson, a nutritionist. “If your muscle reduces, so does your metabolic rate.”

Yet most of us aren’t eating enough protein. In 2020, a study from the University of Sheffield’s Healthy Lifespan Institute found less than half of over-65s studied met the official UK reference nutrient intake (RNI) of 0.8 grams of protein per kilogram (2.2lb) of their body weight per day – or about 50g a day for a 10st person.

I plead guilty. My diet was woefully lacking in protein. But just as I was planning to bring on the steak, a large study published in February found those eating a high-protein diet – more than 1.3g per kg of body weight – were more likely to have “low muscle mass”. Confused? I certainly was.

Mary Ní Lochlainn, lead author of the twin study at King’s College London, says the new findings are not a reason to ditch protein. She explains that those with the highest protein intake got most of their protein from animal sources: “There is some evidence linking red meat with higher rates of inflammation, which can have a negative impact on muscle health.

“Our research showed the importance of eating high-quality protein, including from plants, rather than just larger quantities.”

To be honest, it’s an effort to maintain this high level of protein but I’ve already noticed my new diet is far more filling. So, exactly how much protein should midlifers be consuming?

Increase protein as you get older

Once we hit our 40s, our body’s ability to turn protein into muscle starts to fade, and we need to get more of it from our diet than when we were younger. Without sufficient protein, says Priya Tew, from Dietician UK, “the body can break down existing muscle tissue to make enzymes, hormones and immune system proteins”.

Scientists don’t know exactly why we become less efficient at synthesising protein into muscle as we get older, but in women it could be linked to menopause, and in both sexes, to changes in our gut microbiome.

One study showed better muscle function – including stronger grip strength – in over-65s after they were given a microbe-boosting prebiotic supplement rich in the soluble fibre inulin, a type of soluble fibre found in leeks, onions, asparagus, wheat, garlic, oats, wheat, soy and Jerusalem artichokes.

Sufficient protein may also protect against osteoporosis, because muscles exert tugging forces on bones, which boosts bone density. A study has shown that people with the highest protein intakes have a lower risk of hip fractures.

The more muscle you have the more you’ll need

“Adults over 50 need 1-1.2g per kg of body weight of good quality protein every day for optimum health,” says Tew. According to the European Society for Clinical Nutrition and Metabolism (ESPEN), older people suffering from “acute or chronic illness” should aim for 1.2-1.5g of protein, with even temporarily higher intakes of up to 2g recommended for people suffering from severe illness, or recovering from injury or surgery.

This means that if you are in good health and weigh 10st, you need 63-75g of protein per day – roughly equivalent to two large chicken breasts and an egg or two. Remember that no food is entirely made of protein. A quarter-pounder (113g) beefburger made of 90 per cent beef contains around 18g of protein.

Eat protein at every meal 

University of Sheffield researchers suggest we should consume around 25-30g of protein at each of our three daily meals to optimise muscle. Most people fail to meet the target, especially at breakfast. Adding an egg (6g of protein), smoked salmon (18g of protein in 100g of salmon), authentic Greek yogurt (16g per 150g of yogurt), nuts (6g in 23 almonds) or half a can of beans on two slices of wholewheat toast (17g) and a 250ml glass of milk (9g) are all ways to pack more protein into your morning meal.

Chickpeas, nuts and rice count too

Mary Ní Lochlainn says: “High-quality protein sources are easily digestible and high in essential amino acids especially leucine.” Leucine is a branched chain amino acid (BCAA), which is particularly important as it stimulates the rate at which the body transforms dietary protein into muscle and improves strength.

We need more of this amino acid as we age. Leucine also helps regulate blood sugar, produces growth hormone and may help with weight control. As the body can’t make leucine, it must be obtained from food, Ní Lochlainn recommends eating salmon, chickpeas, nuts, eggs and brown rice.

Vegetarians don’t need to miss out

Once animal foods were considered superior for protein as they are “complete”, meaning they contain all the essential amino acids. Now we know that all the amino acids don’t need to be consumed in one meal, but they can be eaten separately throughout the day.

Studies have found that as long as people eat enough protein – at least 1.1g per kg of body weight – then a vegetarian diet is as effective as one containing meat for building muscle during weight training. Rich sources of plant proteins include nuts and seeds, lentils, soy, quinoa, peas and beans.

Tew says: “If you are vegan or vegetarian, it’s perfectly achievable with some planning.”

Protein bars and powders are worth considering 

“Eating whole foods is always going to be better due to the combination of nutrients. However, protein bars and powder can be useful when you are busy or need a top up,” says Tew.  Daily Telegraph

Nutritionist Kim Pearson says: “Compromised digestive function means people can struggle to effectively digest more dense protein containing foods like meat as they get older. Protein powders are already broken down and so are easier for the body to use, and work well if you have a small appetite.

‘Protein bars and powder can be useful when you are busy or need a top up,’ says Tew Credit: Getty

“Look for high-quality protein powders that provide all of the essential amino acids. They could contain protein from whey or from plant based protein blends like rice, pea and hemp. If choosing whey, opt for organic or at least whey from grass fed cows such as those from The Organic Protein Company. As far as non-dairy options are concerned, I like SunWarriors Warrior Blend or NuZest’s Clean Lean Protein.

“Check the label to ensure that your protein powder contains a minimum of 20-25g of protein per serving, and avoid ones containing added sugars (more natural sweeteners like xylitol, erythritol and stevia are preferable). Also beware of synthetic additives.”

Snack on cheese or Greek yogurt

Protein is so filling you might not need to snack. But if you do, replace biscuits, chocolate and crisps with nuts and seeds, some cooked chicken, a bowl of Greek yogurt or a small piece of cheese. Add weight training to your gym routine

“It’s crucial to add resistance exercise alongside increasing protein intake,” says Ní Lochlainn. This can build muscle as well as reverse the age-related slowdown in the way protein intake stimulates muscle growth.

According to a review in the British Journal of Sports Medicine, people who ate more protein while weight training gained an extra 10 per cent in strength and about 25 per cent more muscle mass than those who did not, especially in the over-40s.

But you don’t need to go mad. The researchers found that eating more than 1.6g of protein a day per kg of body weight didn’t confer any additional benefits. Plus, you don’t need to down a protein shake straight after exercise. The review found that gains were similar if people got their protein immediately after a workout, or in the hours earlier or later.