What happens to your body when it doesn’t get enough protein?

The most common symptom is ankle swelling, but other symptoms include bruising, fatigue, cramps, and brittle or ridged nails. High levels of protein can lead to dehydration and potentially worsen pre-existing or undiagnosed kidney problems

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Protein powder was a new addition to the virtual basket of popular goods used to track the cost of living in 2015. Bought mainly by keep fit enthusiasts and gym-goers, the sports supplement replaced frozen pizza in the list of items monitored by the Office for National Statistics.

The popularity of protein supplements highlights growing awareness of the benefits of consuming a nutrient that also occurs naturally in many foodstuffs. But what is protein and why does your body need it?

What is protein?

A protein is made up of amino acids, which are often described as “the building blocks of life”. Amino acids join up like the beads on a necklace to make a chain. This chain can vary in length from a few beads to many beads. The resulting chain is the protein. The order of the amino acids and the length of the chain determine the type of protein it is. Scientists have discovered thousands of amino acids but only 22 are vital to our body. The human body produces around 13 of these, with the remaining nine sourced from the things we eat and drink.

It’s vital that our protein sources are rich in all nine of these extra amino acids, so it’s important to keep varying the sources of protein. Vegetarians can get enough protein in their diets but do need to monitor the types of protein they take in to make sure they cover these vital amino acids.

Why is protein so important?

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The tens of thousands of processes and reactions that happen within our body each day would not be possible without proteins.

Hormones such as insulin are proteins. The enzymes that help to break down our foods, or trigger key processes in the body, are proteins. Many of the molecules that carry nutrients around the body are proteins. The haemoglobin that carries oxygen around our body is a protein. Proteins also play a vital role in our immune systems. Myoglobin, which is needed for muscle development, is also protein. Protein also plays a part in developing strong bones, and healthy hair and nails.

How do I get protein into my diet?

There are many foodstuffs that offer a rich source of protein. They include lean meats, such as turkey and chicken, beef, eggs, fish and milk.

Many meat substitutes also contain a vegetarian protein, allowing people who opt for a vegetarian diet to ensure they get their recommended amounts also.

As reflected by the ONS’s decision to include protein powders in its “basket of goods”, the use of sports supplements is increasing in the UK. These supplements, common amongst athletes, gym go-ers and body builders, offer a way of getting additional protein into the diet which can support muscle development.

Why might your protein be low?

Generally speaking, we need to consume around 0.65g of protein per kg of body weight each day. However, this depends on physical activity and our general health.

People who are found to have low protein in their body (hypoproteinaemia) are either not taking enough in through their diet, or are unable to absorb it. Malabsorption of food is often found in patients with gut problems, and nutritional deficiencies are often seen in chronic bowel disorders.

Some people, despite taking an adequate amount in through their diet, lose too much protein. The most common way that protein is lost is through the kidneys. The kidneys act like a sieve in filtering the blood, with waste excreted as urine. If there is a problem with the filter mechanism, molecules can pass through it that might not normally and this often includes protein. That is why some kidney function tests measure the amount of protein present in urine.

The liver plays a vital role in protein synthesis and any condition that affects the liver can reduce the amount of protein available for the body.

Some drugs, such as the combined contraceptive pill, can reduce the amount of protein in the body. Other possible causes of low protein are heart failure, pregnancy and some cancers.

Sources of protein for vegetarians

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There are plenty of protein-rich options for vegetarians. Tofu and other vegetarian foods made from soybeans are a rich source of protein, as are members of the legume family, including green peas. Dairy products are also another great source of protein.

Other foodstuffs containing protein that are suitable for vegetarians include soy milk, nuts, chickpeas, lentils, broccoli, spinach and peanut butter.

Edible seeds, including sesame, sunflower and poppy seeds, are another rich source of protein. All beans contain a high amount of protein too.

One of the smartest sources of vegetarian protein is the grain quinoa, which contains all nine of the essential amino acids that the body cannot produce on its own.

What should I do if I suspect I have low protein?

Symptoms indicating low protein can vary significantly due to the vital role it plays in so many aspects of a healthy body.

The most common symptom is oedema, or ankle swelling, which can be a result of water retention due to kidney problems. Other symptoms include bruising, muscle loss, fatigue, cramps, and brittle or ridged nails. People who experience low protein due to liver problems may also experience fluid collecting in the abdomen. Protein is needed for every function of the body, and low protein can be a sign of other problems such as liver, kidney or heart problems.

There are simple blood and urine tests that can be arranged to assess the amount of protein in the body. While the problems caused by low protein can be potentially serious, they can often be tackled by ensuring that there is adequate protein in your diet.

Is it possible to consume too much protein?

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As our kidneys are responsible for filtering the blood, high levels of protein can potentially worsen any pre-existing or undiagnosed kidney problems. This is true for the use of protein drinks and supplements, as well as the high protein diets often credited with helping celebrities lose weight. One of the waste products of filtering protein is the chemical urea. If the kidneys are working hard to process higher levels of protein, the amount of urea may rise in the bloodstream, causing the body to become increasingly dehydrated. Dehydration places a great strain on all of our body systems.

Evidence for the risks of high-protein diets is inconclusive and more research in this area is needed given increased use of these supplements. It is however often advised that people consuming higher levels of protein take care to ensure they are also taking on adequate fluids, such as water, to stay hydrated.

People choosing to use protein powders and other sports supplements should only buy them from a reputable source, and should always follow specified guidelines on maximum daily amounts.

They should also be aware that protein sport supplements are not a suitable meal replacement as they do not contain all of the other nutrients and vitamins that a balanced meal should contain.

Dr Alexandra Phelan is an NHS GP and member of the Pharmacy2u.co.uk Online Doctor Service team