Protein is needed for the cells in your body to grow and repair. Eating foods rich in protein every day is the best way to ensure you get enough of this essential nutrient.

What are proteins?

Proteins are large molecules that are critical to many functions in the body. They do most of the work in the cells and help the body's tissues and organs work.

Most Australians get enough protein in their everyday diets. But it's especially important to make sure you consume enough protein at the times when your cells need to grow or repair, such as when you're a child or teenager, if you're ill or have had surgery or, if you're a woman, when you're pregnant and breastfeeding.

The body also uses protein for energy, particularly if you haven't eaten enough carbohydrates.

If a person is seriously deficient in protein, all their organs will be affected, including the brain, immune system and gut.

How do proteins work?

Proteins are made up of building blocks called amino acids. There are 20 amino acids that combine in different ways in chains to make different proteins.

Individual proteins have different jobs. They include:

• antibodies — proteins that fight infections from viruses and bacteria
• enzymes — proteins that create the chemical reactions in cells and help new molecules to form in the body
• messenger proteins that transmit signals throughout the body, such as hormones
• proteins that provide structure and support for cells
• proteins that transport atoms and molecules throughout the body

Dietary sources of protein

You can source protein from eating a variety of foods such as lean meats, poultry, fish, eggs, milk, nuts, seeds, legumes and beans. This is how many serves a person needs per day, depending on their age and sex:

1 serve of protein is, for example:

• 65g cooked meat such as beef, lamb, veal or pork
• 80g cooked poultry such as chicken or turkey
• 100g cooked fish fillet
• 2 large eggs
• 1 cup cooked or canned legumes/beans such as lentils, chick peas or split peas
• 170g tofu
• 30g nuts, seeds, peanut butter or other nut and seed pastes

High-protein diets

Some people follow high-protein diets when they are on an exercise regime or are trying to lose weight. They may consume extra protein by drinking protein shakes or supplements.

Elite athletes may need extra protein, but most people in Australia already get enough in their everyday diet. Your body can't store protein — any protein you don't use leaves your body as waste.

The best way to build muscle, if that's your goal, is to exercise. The best foods to help fuel your muscles are ones containing carbohydrates.

A high-protein diet for weight loss is generally safe. But it's important to eat high quality proteins such as meat, poultry and fish, and avoid processed meats. You should never cut a single food group — such as carbohydrates — from your diet completely.

If you do decide to follow a high-protein diet, it's a good idea to talk to your doctor or dietitian first.

For more help and information

• To find out more about protein and general nutrition, visit eatforhealth.gov.au.
• Find an accredited practising dietitian on the Dietitians Association of Australia website, or by using the healthdirect service finder.