Proteins

Published by Bupa’s Health Information Team, November 2010.

Every cell in your body contains protein and it has a number of important functions. Most people get enough protein by eating a healthy, balanced diet. This article will explain why you need protein and how to make sure you’re getting enough.

What is protein?

Proteins are complex substances made up of chains of amino acids. Amino acids are building blocks that combine in different formations to make up the proteins in your body. There are 20 amino acids in total – your body can make some of these itself, but there are eight that you can only get from protein that you eat. These are called essential amino acids.

When you eat protein, it’s broken down into amino acids. These can then be rearranged into new proteins that your body needs.

Why do I need protein?

Protein is essential for healthy growth of all body tissues – such as your muscles (including your heart), internal organs (such as your lungs and liver) and skin – and also for repair of these tissues. On top of this, it’s a good source of energy too.

What foods contain protein?

Different foods contain different amounts of amino acids. Foods that are high in protein are said to be either complete or incomplete proteins. Complete proteins contain all the essential amino acids, whereas incomplete proteins contain some but not all of them.

On the whole, you can only get complete proteins from animal products such as meat, fish, dairy produce and eggs. The only plant proteins that contain all the essential amino acids are soya beans and foods made from them, and a grain called quinoa. Examples of incomplete proteins include beans and other pulses, nuts and seeds and cereals. However, most people living in the developed world eat a wide range of foods that contain protein so even if you’re a vegetarian, you’re likely to be getting all the amino acids your body needs.

How much protein do I need?

Although you can estimate how much protein you need to eat, it’s impossible to set exact guidelines as requirements will vary depending on factors such as how much you weigh and how old you are. However, on average, two to three servings a day will be enough to meet your body’s needs. As a guide, a portion could be two eggs or a piece of cooked meat (100g) or fish (140g) about the size of a deck of cards.

Even if you’re not a vegetarian, it’s still important to eat a variety of different types of foods that contain protein. Try to eat two portions of fish a week, of which one is an oily fish such as sardines, salmon or mackerel.

Eating too much?

Although meat is an excellent source of protein, there is a down side as some types can be very high in fat. Too much fat in your diet can lead to health problems such as heart disease and high blood pressure. Some tips that will help you to lower how much fat you eat but still give you the protein you need include:

• choosing lean cuts of meat
• removing the skin from chicken and turkey
• cutting off excess fat that you can see
• allowing meat to cook so the fat can drain away
• reducing the amount of high-fat meat products, such as sausages and burgers, in your diet

Try to vary the protein-containing foods that you eat so that you’re not relying solely on meat.

You may have heard of the Atkins diet that involves eating lots of protein-rich food and cutting down on the amount of starchy food you eat. This has raised some concerns about the possible health effects too much protein can have on your kidneys and liver. Although there doesn’t appear to be any evidence that it can damage these organs, following this diet may increase your risk of heart problems because many complete proteins are high in fat. There also doesn’t appear to be any evidence that following a high-protein diet is any more effective for long-term weight loss than eating a healthy, balanced diet.

Eating too little?

Most people in the UK and the rest of the developed world get more protein than they need in their diet. Even elite athletes who need extra protein to build and maintain their muscles are probably getting enough. You may have heard about protein supplements that claim to boost your muscle strength, but there is no evidence to suggest that they are of any benefit. You’re better off getting the protein you need by eating a balanced diet with a good variety of animal and plant sources of protein.

However, in some parts of the world, getting enough protein in the diet is more of a problem and millions of people, particularly children, develop a condition called kwashiorkor. This can lead to problems such as poor growth, muscle wasting, increased risk of infections and often death.

If you’re trying to lose weight and eating a very restricted diet, you may not be getting as much protein as is recommended. If you’re not eating enough, your body will start to use its stores of protein for energy, resulting in your muscles becoming weaker.

Protein power

It’s really important to include protein in your diet so that your body can grow and repair itself. Try these tips to make sure you’re getting enough in the healthiest way possible.

• Even if you’re not a vegetarian, make sure you don’t just get your protein from meat and dairy products as these are often high in fat.
• Eating fish twice a week and including a portion of oily fish can give you a healthy protein boost and may also help to protect your heart.
• By combining different incomplete proteins, you can easily get all the amino acids your body needs to be healthy.

For sources and links to further information, see Resources.