How Much Protein Do You Really Need? An Evidence-Based Guide

What Protein Does in the Body

Protein is one of the three macronutrients, alongside carbohydrate and fat. It's made up of building blocks called amino acids, which your body uses to build and repair muscle, skin, hair, enzymes, hormones and antibodies. Unlike fat, the body has no large dedicated store of protein to draw on, so a regular dietary supply matters.

There are 20 amino acids. Nine of these are described as 'essential' because your body can't make them and must obtain them from food. The remaining ones can be synthesised internally. The quality of a protein source is largely about whether it supplies all nine essential amino acids in useful amounts.

Beyond muscle, adequate protein supports immune function, wound healing and the maintenance of bone and lean tissue as we age. It also tends to be the most satiating macronutrient, meaning protein-rich meals help many people feel fuller for longer, which is one reason higher-protein eating patterns are popular for weight management. That said, protein is part of a whole diet, and balance with quality carbohydrates, healthy fats and plenty of plants matters more than chasing any single nutrient.

How Much Protein Do Australians Actually Need?

The National Health and Medical Research Council (NHMRC) sets a Recommended Dietary Intake (RDI) for protein, the amount that meets the needs of nearly all healthy people. For adults, this is approximately 0.84 grams per kilogram of body weight per day for men and 0.75 grams per kilogram for women (NHMRC, 2017).

For a 70 kg man, that's around 59 grams a day; for a 65 kg woman, around 49 grams. To put that in perspective, you might reach that with a couple of eggs at breakfast, a palm-sized serve of chicken or tofu at lunch, and a serve of legumes or fish at dinner.

It's worth understanding that the RDI is a baseline designed to prevent deficiency, not necessarily the optimal amount for every goal. Needs rise in several situations: during pregnancy and breastfeeding, in older adults, in people doing significant resistance or endurance training, and during recovery from illness or surgery. Sports nutrition guidelines, for example, often suggest 1.2–2.0 grams per kilogram per day for people training seriously to build or maintain muscle (Dietitians Australia, 2023). Most Australians who eat a varied diet already meet or exceed the basic RDI; outright protein deficiency is uncommon here, but distribution and quality can still be improved.

Protein and Ageing: A Special Case

One of the most important and under-appreciated facts about protein is that requirements appear to rise with age. As we get older, the body becomes less efficient at turning dietary protein into muscle, a phenomenon known as 'anabolic resistance'. At the same time, age-related muscle loss, called sarcopenia, accelerates.

Sarcopenia matters because muscle is closely tied to strength, balance, metabolic health and the ability to stay independent. Loss of muscle and strength is a major contributor to falls and frailty in older Australians, and falls are a leading cause of injury-related hospitalisation in people over 65 (AIHW, 2023).

Many experts in healthy ageing suggest that older adults benefit from protein intakes above the standard RDI, often in the range of 1.0–1.2 grams per kilogram per day, spread fairly evenly across meals, and combined with resistance exercise to stimulate muscle maintenance. Spreading protein across the day (rather than eating most of it at dinner) may help, because each meal provides a fresh stimulus for muscle protein synthesis. Older adults considering changes to their diet or starting resistance training should speak with their GP first, particularly if they have kidney disease or other chronic conditions.

Protein Quality: Animal and Plant Sources

Not all protein is equal in terms of amino acid profile. Animal proteins (meat, poultry, fish, eggs and dairy) are 'complete', meaning they contain all nine essential amino acids in good proportions. Most individual plant proteins are lower in one or more essential amino acids, though soy, quinoa and a few others are exceptions that are essentially complete.

This does not mean plant-based eaters can't meet their needs; they very much can. The key is variety. Combining different plant proteins across the day, for example legumes with grains, or nuts and seeds with wholegrains, easily provides the full set of essential amino acids. It's a myth that these foods must be eaten in the same meal; your body maintains a pool of amino acids across the day.

Good protein sources commonly available in Australia include: lean red meat, chicken, fish and seafood, eggs, Greek yoghurt, milk and cheese, legumes (lentils, chickpeas, beans), tofu and tempeh, edamame, nuts, seeds, and wholegrains. From a whole-health perspective, including more plant proteins and choosing fish and lean options over large amounts of processed and red meat aligns with both the Australian Dietary Guidelines and what we know about heart and bowel health.

Support your goals with the full picture

Whether you're building muscle, managing weight or ageing well, blood testing can help you and your GP keep an eye on your metabolic health as your diet changes.

Start Testing Today

Developed by leading doctorsNo waiting, no referrals2,000+ locations Australia-wide

Can You Have Too Much Protein?

High-protein diets are widely promoted, and for most healthy people, moderately higher protein intakes are safe. But more is not automatically better, and a few points deserve attention.

Kidneys: A common concern is that high protein harms the kidneys. In people with healthy kidneys, current evidence does not show that higher protein intake causes kidney damage. However, in people who already have chronic kidney disease, protein intake may need to be carefully managed under medical supervision, which is one reason testing matters before making big dietary changes.

Displacement and balance: When protein crowds out other important foods (vegetables, wholegrains, legumes, fruit), the overall diet can suffer. Very high intakes of processed and red meat in particular are associated with increased risk of bowel cancer, so the source of protein matters, not just the amount. The World Health Organization classifies processed meat as a cause of bowel cancer and red meat as a probable cause.

Supplements and powders: Protein powders can be a convenient way to top up intake, but they are supplements, not magic. Most people who eat enough food don't need them, and in Australia they're regulated as either foods or complementary medicines depending on their claims. Whole foods bring fibre, vitamins and minerals that isolated powders lack. If you have a medical condition, are pregnant, or have kidney problems, check with your GP before significantly increasing protein or starting supplements.

What Blood Tests Can, and Can't, Tell You About Protein

There is no simple blood test that measures 'how much protein you eat'. However, a few markers relate to protein status and overall nutrition, and your GP may use them in context.

Albumin is the most abundant protein in your blood and is included in many routine panels. Low albumin can sometimes reflect poor nutrition, but it's also affected by inflammation, liver and kidney function and illness, so it's a non-specific marker and not a reliable measure of dietary protein on its own. Total protein and the albumin/globulin ratio give a broad picture of the proteins circulating in your blood.

For people increasing protein as part of a fitness or weight-management plan, the more useful blood tests are often the ones that track overall metabolic health, such as kidney function (in case higher protein needs monitoring), lipids and blood sugar markers. These help ensure that a dietary change is supporting your health rather than working against it.

The honest summary is that protein needs are best estimated from your body weight, age, activity level and goals, not from a blood test. Blood testing is most useful for checking that the rest of your health is on track as you make changes, and for catching conditions, like kidney disease, that would change the advice. Interpret any results with your GP.