What are proteins?

Protein is needed for cells in the 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.

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 to work.

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

The body also uses protein for energy, particularly if you have not 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

How much protein do I need?

The amount of protein you need depends on your age, gender and stage of life. Most Australians have more than enough protein in their everyday diets.

Person	Serve
Babies 0-6 months	10g/day
Babies 7-12 months	14g/day
Children 1-3 years	14g/day
Children 4-8 years	20g/day
Girls and boys aged 9-13 years	35-40g/day
Girls aged 14-18 years	45g/day
Boys aged 14-18 years	65g/day
Pregnant women	60g/day
Breastfeeding women	67g/day
Women aged 19-70 years	46g/day
Men aged 19-70 years	64g/day
Women aged 70+	57g/day
Men aged 70+	81g/day

Source: NHMRC

What foods are high in protein?

You can source protein from eating a variety of foods such as lean meats, poultry, fish, eggs, milk, nuts, seeds, legumes and beans.

You can find healthy proteins from plants or animals. All people, not just vegetarians and vegans, can choose plant-based protein foods for variety.

Plant-based proteins

• Legumes: Legumes are high protein and contain other nutrients that can lower cholesterol, as well as fibre. Good choices include beans, chickpeas, lentils, split peas and soybeans.
• Tofu: Tofu is high in protein and is a good substitute for meat or poultry.

Animal-based proteins

• Fish and seafood: 2-3 serves of fish or seafood a week is good for the heart. A serve is 150g.
• Eggs: Eggs contain high protein as well as vitamin A, E and B12, selenium choline and iron and cholesterol. If you have high cholesterol, type 2 diabetes or heart disease you should not eat more than 7 eggs a week.
• Poultry: Enjoy poultry such as chicken, turkey and duck as part of a healthy balanced diet.
• Red meat: Red meat is an excellent source of protein, but it has been linked to heart disease and stroke so limit it to 1 to 3 meals of lean red meat per week. Red meat includes beef, veal, pork, lamb and kangaroo.
• Dairy: Protein is found in milk, cheese and yoghurt. These also contain calcium and protect against disease. Choosing mostly low-fat varieties is best for health.

Protein is also found in processed meats such as ham and salami. But these tend to be high fat and high salt and contain a lot of additives. It is best to avoid or limit processed meats.

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 cannot store protein — any protein you do not 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. This means you change the balance of foods to eat more protein and fewer carbohydrates. Eating more protein helps you to feel full for longer, boosts the metabolism, causes greater fat loss and less muscle loss, and reduces food cravings.

But it is 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.

Resources and support

• 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.