The Truth About Protein Supplements

The Truth About Protein Supplements


Protein supplements were once confined to the bodybuilding world but now fill the shelves in supermarkets, health food stores and pharmacies. The most common reasons for using protein supplements are to build muscle, to aid post-exercise recovery or to control weight. The surge in availability of protein supplements has been accompanied by sleek branding and aggressive marketing by supplement companies. It can be difficult to sort the fact from the fiction. So do you really need a protein supplement or does a healthy diet suffice?

The Role of Protein

Protein occurs in all living cells, accounting for ~15-20% of total body mass. Approximately half of the body’s protein is present as skeletal muscle, but protein is also an important building block of other tissues, including bone, cartilage, skin and blood as well as functional molecules such as enzymes and hormones.

Protein is made up of structural units called amino acids. When combined with strength training, they provide the building blocks for muscle growth and repair for athletic and aesthetic benefits.

But can this be achieved sufficiently from the protein in our diets? The answer, for the most part is yes.

Too much of a good thing?

The supplements industry tends to give the impression that ‘more is better’, however this is not necessarily true, and in some cases can be detrimental our health.

Some of the potential risks of excess protein or overuse of protein supplements are:

  • Excessive amounts of protein present an additional load on our kidneys to filter the waste products of protein breakdown (creating some expensive urine), so is problematic for anyone with existing kidney impairment. (Friedman, 2004)
  • Excess protein may disrupt the healthy balance of our gut bacteria. Our most valuable gut bacteria thrive off fibre, whereas excess protein can reduce numbers of beneficial bacteria. (Valdes, 2018)
  • Protein supplements have been linked to disordered eating. Body-conscious men are using these supplements for weight loss, setting them up for potential eating disorders. (Achiro, 2010)
  • Protein supplements may contain heavy metals. Reports from the USA also indicate risk of heavy metal poisoning with high use of protein powders. (Clean Lavel Project, 2018)
  • Soy products are safe for human consumption, protective for human health, and do not contribute to hormonal or thyroid imbalance, however there may a slightly higher risk of adverse effects such as heartburn, stomach pain or discomfort, swelling, abdominal distension, bloating, flatulence, and constipation or diarrhea with the consumption of higher soy diets and beverages (amounts of soy protein ranging from 20-60 g/day). (AHRQ, 2005)

How much Protein?

The American College of Sports Medicine indicate that protein requirements range between 1.2-1.7g per kilogram of body weight. For an 80kg athlete this would be 96-136g/day. The higher end of this range is reserved for elite endurance and power athletes, whereas the lower end would be sufficient for the majority of gym goers.

The 2011-12 Australian Health Survey indicates that the most Australians easy meet their protein requirements. The average (including sedentary) male consumes 1.2g/kg/day and the average female 1.1g/kg/day suggesting we are already achieving this target on a typical diet without consciously following any high protein diets or using supplements. Numerous dietary surveys indicate the normal diets of strength-based athletes provide close to 2g/kg/d, even before any use of protein powders. This national data shows that it is quite achievable to include appropriate protein from food alone.

When to consider supplements

So, do protein powders have any merit? Yes, there are instances where it becomes an appropriate or convenient option, including:

  • For travelling athletes when a food form of protein is not practical in terms of storage/ travel/ time.
  • Boosting the protein content of food options naturally low in protein.
  •  When rapidly digested protein is required during a busy training schedule
  • An alternative to food is required when appetite is poor.
  • Some athletes may have goal to lose weight and restrict energy for a period, making it a little harder to meet protein requirement to protect muscle.
  • Athletes who choose a vegetarian or vegan lifestyle may find it harder to meet protein targets particularly as plant-based proteins have a lower biological value – meaning that a lower amount of this protein is absorbed and digested.

How much?

When the convenience of protein supplements outweighs the cost, intake should be restricted to 1-2 serves a day. Individual doses should be limited to an intake of no more than 20-30 grams.

Does timing matter?

Another highly debated concept is that optimal timing for protein after strength training. It is still uncertain for how long the ‘window’ is to consume 20g high quality protein to stimulate muscle protein synthesis, however it likely lasts hours rather than having to chug down the protein shake immediately after a workout. Research strongly suggests that regular protein intervals through the day (not dissimilar to a normal eating pattern) is optimal, or roughly 15-30 at each snack or meal.

Source: Sports Dietitian Australia

What are the different types of protein and how are they different?

Not all protein sources are created equal, with different digestion and absorption rates. Animal sourced proteins such as that from eggs and most meats are considered high biological value (HBV); essential amino acids in a form that is readily digested.

Protein supplements can be broadly classified according to their nutrient profile of protein +/- carbs +/- a range of proposed ergogenic (provide a performance benefit) ingredients such as creatine, specific amino acids and proposed fat metabolisers, plus vitamins and minerals.

The main types of protein supplements include:

Protein Description
Whey Protein Concentrate (WPC)70-80% protein by weight, small amounts of lactose and fat.
Whey Protein Isolate (WPI)further filtration of WPC, ~90% protein by weight
Whey Protein Hydrolysate (WPH)Derived from WPC or WPI. Shorter peptides or amino acid chains, supposedly resulting in even more rapid digestion and absorption. Evidence to date is preliminary and conflicting.
Casein or Calcium CaseinateHBV protein that makes up ~80% of the protein in milk. Casein clots in the acidic environment of the stomach, slowing digestion and delivery of amino acids to the body.
Soy Protein – concentrate or isolateHBV, rapidly digested protein. Often used in mixed protein supplements, and protein bars as it is cheaper than whey.
Egg AlbuminA HBV protein source free of fat and carbohydrate. More expensive than newer dairy derived proteins.

Most protein in supplements is whey protein which travels to the bloodstream quickly and appears to have a stronger anabolic (muscle building) effect on muscle, largely due to the composition of a specific essential amino acid called leucine. 2-3g leucine has been shown to be the optimal amount to activate muscle building machinery in our body.

Leucine content of Foods

Source: Sports Dietitian Australia

What else is a good source of leucine as a recovery drink? Good old chocolate milk gets the AIS tick of approval. It has the right mix of carbohydrates for glycogen restoration (to store glucose for when we need it) and stimulate insulin release for optimal protein uptake, as well contributing to rehydration.

What about other ingredients in supplements?

The inclusion of other proposed ergogenic ingredients may do little else but add unnecessary expense to the product. Even for ingredients with proven performance potential such a creatine monohydrate, intake of these products may be best prescribed in isolation (i.e. pure creatine monohydrate supplement), rather than as part of a ‘one stop shop’ protein powder where individual dosing of active ingredients is not possible. Evidence to date suggests there is little value in the prescription of individual amino acids.

Bar or shake?

To facilitate the creation of a bar, variable amounts of carbohydrate and fat are required, with lower quality ‘protein blends’ typically used in preference to WPI to moderate costs. Taking information gleaned from very low calorie supplements, a bar is also likely to have higher satiety compared to a liquid, the implications of which will depend on the specific goal of the athlete.

Can’t get no satisfaction?

Recent evidence suggests that whey protein may offer greater satiety (fullness) than other whole proteins, alluding to a potential role in weight loss. Weight loss needs to be viewed in the context of looking at the whole diet patterns, choices and sustainability rather than using a single supplement as a proponent for success. There is no evidence in relation to supplements marketed as ‘fat blasters’ or advertised to magically boost your metabolism and cause weight to fall off.

Bottom line: For the biggest performance gains, a varied diet with consideration to regular and quality sources of protein, adequate rest and hard work is the key. Higher quality supplement powders such as Whey Protein Isolate may provide a complementary role.

To book an appointment with an Accredited Practising Dietitian at Ethos Health, contact us on (02) 4962 8700 or book online

To find an accredited sports dietitian in your area visit

Further Reading:

Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance

Sports Dietitian Australia:

AIS resources:

A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults

Tim Crowe’s website:

Chocolate milk for recovery from exercise: a systematic review and meta-analysis of controlled clinical trial

Balk E, Chung M, Chew P, Ip S, Raman G, Kupelnick B, et al. Effects of soy on health outcomes. Evid Rep Technol Assess. 2005 [cited 2013 Sep 11];(126):1-8. Citation available from:

Hooper L, Ryder JJ, Kurzer MS, Lampe JW, Messina MJ, Phipps WR, Cassidy A. Effects of soy protein and isoflavones on circulating hormone concentrations in pre- and post-menopausal women: a systematic review and meta-anlaysis. Hum Reprod Update. 2009 [cited 2013 Sep 11];15(4):423-40. Abstract available from:

Excessive Workout Supplement Use: An Emerging Eating Disorder in Men from

Clean Label Project 2018 survey of Protein Powders:

Valdes AM. Role of the gut microbiota in nutrition and health. BMJ 2018

Friedman, A. N. (2004). High-protein diets: Potential effects on the kidney in renal health and disease. American Journal of Kidney Diseases, 44(6), 950–962.

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