Protein guide

Often described as a ‘building block’ of life, protein is fundamental to how our bodies work. It’s the second most prolific compound in the body (after water), and it’s something we all need to consume on a daily basis to maintain good wellbeing.

So, what is protein and why do we need it so much? Like fat and carbohydrates, protein is known as a ‘macronutrient’, which means that we need relatively large amounts of it compared to micronutrients like vitamins and nutrients. However, because the body has no way of storing protein, we need to keep levels ‘topped up’ through what we eat.

What is protein?

It’s a vital element of every cell and tissue in the body – our hair and nails are mostly made of protein and it’s also crucial to bones, muscles, cartilage, skin and blood.

Not only does is play an important role in building and repairing tissues, it also gives the body around 10-15% of its dietary energy. In short, protein helps to power us through life.

What are proteins and how is protein broken down?

Protein is made up of long chains of amino acids. When we eat, our bodies cleverly take protein from the food and it’s broken down into amino acids that are used to perform different body functions.

There are 20 different amino acids found in plant and animal proteins, and eight of these are considered to be essential for adults to consume in their diets. The other non-essential amino acids can be made in the body through a process called transamination.

Protein deficiency and health risks

Thanks to our varied diets in the UK, it’s relatively easy to get enough protein from what we eat. But if your body isn’t getting enough protein it can affect a range of body functions.

Symptoms of lack of protein

• Hair, nail and skin issues – when your body can’t make proteins like elastin, collagen, and kerati it can lead to thinning hair, dry and flaky skin and brittle nails.
• Muscle wasting – if your body isn’t getting enough protein over a long period of time it can affect the muscles that take care of movement, especially in older people. This can lead to tiredness, problems with balance and lower metabolism.
• Slow body repair – we need proteins to make our blood clot, so cuts can take longer to heal than they should.
• Low immune system – amino acids in the blood help the immune system to fight off viruses, bacteria, and toxins. Without enough protein it can be a challenge for this process to work effectively.
• Edema – this is a symptom of severe protein deficiency, which causes swollen and puffy skin. Any swelling around the abdomen, legs, feet and hands should be checked out by your doctor.

What are the side effects of too much protein?

Studies have shown that high-protein diets are often high in red meat, which has been linked to an increased risk of health issues, including cancer, heart disease and type 2 diabetes.

Other research looking at the kinds of foods typically eaten on a high-protein diet suggests that they could lead to constipation, diarrhoea, dehydration and bad breath. And, the NHS warns that consuming too much protein can increase risk of osteoporosis and worsen existing kidney problems.

How much protein do you need?

This depends on your weight, gender and age. As a guideline, it’s recommended that adults eat 0.75g of protein per kilogram of bodyweight.

How much protein does the average person need per day?

• Women – 45g
• Men – 56g
• Children aged 4-13 – around 20-35g
• Teen girls – 46g
• Teen boys – 52g
• Over 65s – people over the age of 65 could benefit from higher levels of protein to help deal with the loss of muscle mass, strength and function that comes with aging.

It’s likely that you need less protein than you might imagine. In the UK, the average adult typically eats a lot more protein than they need to – 88g for men and 64g for women. For most of us, around two daily palm-sized servings of protein should do the trick.

What are high protein foods?

Despite the huge range of protein-boosting supplements, drinks, shakes and snacks on the market, the majority of us can happily get all the protein we need from a healthy, balanced diet.

Protein in animal-based food

The most obvious sources of protein come from meat and dairy products, and that’s because many of them are ‘complete’ proteins, or foods that contain all nine essential amino acids.

Always choose your proteins carefully. It’s important to steer clear of processed meat, avoid a diet that’s too high in red meat and make sure you’re getting a good variety of plant-based proteins too.

• Eggs – a single egg contains over six grams of protein, along with essential amino acids, vitamins A, E and B12.
• Meat – branched-chain amino acids (BCAAs) are found in meat and play an important role in supporting muscle recovery. Try to opt for lean protein from chicken and turkey. If you’ve been exercising go for pork, one of the richest sources of leucine, which helps to stimulate repair after exercise.
• Fish and seafood – a great low-fat source of protein.
• Dairy food – milk, cheese and yoghurt; Greek yoghurt is a particularly impressive source of protein.

What plant-based food is protein in?

Even vegetarians and vegans can get enough daily protein, providing they do the research and incorporate the right foods into their diets.

If you’re on a plant-based diet, one of the most important rules is to make sure you consume a variety of protein sources. That’s because there are fewer complete proteins from plant-based sources, although quinoa and pea protein both give a wide range of amino acids in one source.

It’s a good idea to look at combining two different protein sources to provide the same kind of amino acid profile as you would get from meat.

Good sources of plant-based proteins include:

• Soya – such as soya milk and tofu.
• Beans and pulses – not only are these high in protein, they are also great for iron and fibre.
• Grains – you’ll find good protein content in quinoa, brown and white bread, rice, pasta and oatmeal.
• Nuts and seeds – almonds, walnuts, pistachios, hazelnuts and sunflower seeds are all great go-to sources of protein.

Protein and weight loss

Protein has become something of a buzz word in the dieting industry. High protein/low carb eating plans like The Atkins Diet, ketogenic (or ‘keto’) diets and paleo diets have soared in popularity – but do they live up to the hype?

In the short-term, these diets may reduce hunger and calorie intake, leading to those excess pounds dropping off. But there’s little evidence for long-term weight loss benefits, possibly because we either find it hard to stick to them for long or because our bodies get used to the change in diet.

On keto diets, the aim is to eat very small amount of carbs, forcing the body into a metabolic state called ‘ketosis’ – the same state caused by starvation. This can lead to rapid weight loss, but cutting out an entire food group isn’t advised as a healthy approach to losing weight. Read our article what is a ketogenic diet to find out more about this controversial eating plan.

Building muscle on a high protein diet

The amino acids in protein are like the building blocks of muscle growth. If bodybuilding is high on your agenda, you may well have been tempted by marketing messages on protein powders, bars or shakes that promise to help you build muscle.

The harder you train, the more amino acids your body needs to help rebuild muscle fibre, so there’s some truth in the claim that bodybuilders need more protein. However, experts claim that it’s possible to enhance your protein content through simple changes to your diet.