The short answer
Most people don't need protein powder. You can usually get enough protein from food. A powder can be a handy top-up if:
- you're doing regular resistance training and struggle to eat enough protein;
- you're older, recovering from illness or injury, or have a small appetite;
- you eat a plant-based diet and need a convenient protein source.
If you buy one, look for about 20–30 g of protein per serve and a short ingredient list. If you're a tested athlete, choose a batch-tested product.
Protein powders are everywhere, and the marketing can make them sound essential. As a dietitian, I find most people are already eating enough protein, but a powder can be useful in some situations. Here's how to tell whether you need one and how to choose a good one.
Do you need protein powder?
Probably not, if you eat a varied diet. Australian guidelines recommend adults get about 0.84 g of protein per kilogram of body weight a day for men and 0.75 g/kg for women, rising to about 1.07 g/kg and 0.94 g/kg after 70.6 For a 70 kg man, that's about 60 g a day, which most Australians get from food.
If you do regular resistance training, your needs are higher. A meta-analysis of 49 trials found protein supplements helped people gain a little more muscle and strength from resistance training, but the benefit levelled off at a total intake of about 1.6 g/kg a day.1 Beyond that, extra protein didn't add more muscle.
A protein powder may be useful if you:
- do regular resistance training and find it hard to reach your protein target with food;
- are trying to gain weight or muscle and have a small appetite;
- are recovering from an injury, surgery or illness;
- are an older adult who struggles to eat enough protein;
- eat a vegan or plant-based diet and want a convenient option.
For teenagers, even those training hard, food should come first. Talk to a sports dietitian before adding supplements.
What are the main types of protein powder?
- Whey: a complete dairy protein that's digested quickly, so it's popular after workouts. Whey isolate has less lactose than whey concentrate.
- Casein: the other main dairy protein. It's digested slowly, so some people prefer it before bed.
- Soy: a complete plant protein with a good amino acid profile. A meta-analysis of 18 trials found soy didn't change thyroid hormone levels.4
- Pea: a plant protein that's low in common allergens and closer to complete than most plant proteins.
- Rice: low in some essential amino acids on its own, so it's often blended with pea.
- Hemp: made from hemp seeds, which have been permitted as food in Australia and New Zealand since 2017. It's lower in protein per serve than most other powders.
Plant blends (such as pea and rice) give a more complete amino acid profile than a single plant source.
Not sure if you need a supplement?
Find practitioners on HealthBank who give supplement and sports nutrition advice. Many offer a free discovery call, online, by phone or in person.
Find a nutrition practitioner →How do you choose a protein powder?
Start with your goal and any allergies or intolerances, then check the nutrition panel and ingredient list. Supplement marketing often overpromises, and a more expensive powder isn't necessarily better.
- Protein per serve: look for about 20–30 g.
- Short ingredient list: fewer added extras makes it easier to see what you're getting.
- Low added sugar: unless you want a recovery drink with carbohydrate, look for a few grams or less per serve.
- Suits your gut: if you're lactose intolerant, choose whey isolate or a plant protein.
- Batch-tested: essential if you compete in tested sport (see below).
You don't need added BCAAs or glutamine. Branched-chain amino acids alone can't fully drive muscle building, because your body needs all the essential amino acids to make new muscle protein.2 A complete protein already contains them.
Compete in tested sport?
Supplements, including protein powders, can contain banned substances that aren't on the label. A review of 23 studies found unlisted prohibited substances in a range of sports supplements.5 If you're subject to drug testing, choose batch-tested products and check Sport Integrity Australia's advice before you buy.
Which ingredients should you check?
Most protein powder ingredients are safe for most people. These are the ones worth checking if they matter to you:
- Lactose: whey concentrate, casein, skim milk powder and milk solids contain more lactose, which can cause bloating or wind if you're lactose intolerant.
- Gluten: some powders contain gluten. Avoid these if you have coeliac disease.
- Sweeteners: sucralose (955), aspartame (951), saccharin (954) and stevia are approved for use in Australia. A large review found no clear harms or benefits for most health outcomes, though the evidence was limited.3 Sugar alcohols such as xylitol can cause gut symptoms in some people.
- Maltodextrin and added sugars: these add carbohydrate. That's fine in a recovery drink, but not ideal if you just want protein.
- Gums and thickeners: such as xanthan gum. Generally safe, but some people find they cause bloating.
Want a plan that fits your training?
HealthBank practitioners who work in sports nutrition and supplement advice can work out how much protein you need and whether food alone will get you there.
Find a nutrition practitioner →Frequently asked questions
Do I need protein powder?
Most people don't. It can help if you're training hard and can't meet your protein needs with food, or if you're older or recovering from illness.
How much protein do I need a day?
Australian guidelines recommend about 0.84 g/kg for men and 0.75 g/kg for women, with higher needs after 70 and with regular resistance training.
Which protein powder is best?
There's no single best one. Whey is a good complete protein; soy or a pea and rice blend suit plant-based diets. Look for 20–30 g of protein per serve.
Is soy protein bad for your hormones or thyroid?
A meta-analysis of 18 trials found soy didn't change thyroid hormone levels. Soy is a good complete plant protein.
Can protein powder contain banned substances?
Yes, some supplements contain unlisted banned substances. Tested athletes should choose batch-tested products.
References
Research (PubMed)
- Morton RW, Murphy KT, McKellar SR, et al. 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. Br J Sports Med. 2018;52(6):376–384. PubMed 28698222
- Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr. 2017;14:30. PubMed 28852372
- Toews I, Lohner S, Küllenberg de Gaudry D, et al. Association between intake of non-sugar sweeteners and health outcomes: systematic review and meta-analyses of randomised and non-randomised controlled trials and observational studies. BMJ. 2019;364:k4718. PubMed 30602577
- Otun J, Sahebkar A, Östlundh L, Atkin SL, Sathyapalan T. Systematic review and meta-analysis on the effect of soy on thyroid function. Sci Rep. 2019;9(1):3964. PubMed 30850697
- Martínez-Sanz JM, Sospedra I, Ortiz CM, et al. Intended or unintended doping? A review of the presence of doping substances in dietary supplements used in sports. Nutrients. 2017;9(10):1093. PubMed 28976928
Australian guidelines
- National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand: protein. View source
This article is general information and isn't a substitute for personalised advice. Speak to your practitioner about your situation.
Robbie is a Sydney-based Accredited Practising Dietitian (APD) and Exercise Scientist with over 17 years of experience. He holds a Bachelor of Exercise Science (Nutrition) and a Master of Nutrition and Dietetics, and is the Director and Co-founder of HealthBank.