“Have you got a protein supplement yet?” the personal trainer asks, glancing up from his checklist to meet my eyes. “We might need to work it into a diet plan”, he explains, noticing my hesitation.
I’ve just signed up for a gym for the first time in my adult life, and I’m meeting with a personal trainer to get my exercise plan together. I’m not as unfit as I once was — at this point, I’m 85kg, down from 115kg a few years earlier — but still can’t do a single pull-up, which I’ve set as my fitness goal.
“No”, I say, and he ticks another box. We move on to my current exercise regimen (lacking) and my diet (poor).
Protein powders are as ubiquitous in the exercise world as sweat. Every muscle-bound hulk at the gym chugs down a chalky blend of protein, water, and magic before or after their workout. We are told that this one simple dietary intervention can do the impossible.
It can make us stronger. Build more muscles. Make fitness less a dream and more a wonderful reality.
For most people, this simply isn’t true.
There’s no evidence that, for the average human being, protein powders do much of anything at all.
There’s a big disclaimer for this piece. You see, here I’m talking about the “average” person — your normal, slightly overweight person who takes up a gym membership. Maybe even your reasonably fit jogger who wants to get a bit better at lifting.
We are NOT talking about bodybuilders who are hitting the gym 6–7 times a week*.
The thing is, most people shopping around for a protein powder — like me, sitting across from a really fit guy when I joined my gym — aren’t elite athletes. They’re looking to get some bigger muscles, maybe get a bit fitter, and they’ve been told that the best way to do this is to up their protein intake.
More specifically, to add a new powder to their daily diet.
So what’s the evidence behind protein supplements?
Getting Swole — Scientifically
The basic idea behind protein supplementation checks out fine — you need protein to build muscle, and more protein probably means more muscle. If you take that in powdered form instead of, say, eggs, even better!
The issue is, most people already eat a reasonable amount of protein. Your average person has ~50-60grams per day already, with young, fit people often taking in significantly more than that. I calculated my daily intake based on an average weekday**, and it came out to ~100grams of protein.
The question then becomes not “how much protein do I need?”, but “how much MORE protein do I need?”
This, it turns out, is a much more difficult question to answer.
In 2015, a group of researchers did what’s known as a systematic review to try and figure out what the benefits were to protein supplements. They looked at dozens of studies, and collated the evidence into one big review.
The results were…not amazing.
Firstly, the state of the evidence is terrible. There are virtually no long-term studies done looking at protein powders that aren’t either a) too small to be useful or b) really badly done.
That being said, even if you ignore the poor quality of virtually all studies done on protein supplementation, the evidence is extremely limited. There are very few studies that have found a functional benefit — i.e. being able to actually lift more — when comparing people who take a protein powder to those taking a carbohydrate control.
Even for people who were doing a lot of exercise, there was no consistent benefit from protein powders. This was likely because, as the review noted, that these people already ate a bunch of protein in their diet and so adding some more in the form of a supplement just didn’t do that much more for their strength.
Another review in 2012 looked specifically at the claims made by protein powders on their marketing material, and found that only 4% of them are backed by good evidence.
There’s also some evidence of side-effects associated with protein powders, in particular for less-known brands that may not have good quality controls.
What does this mean for you, the average person trying to build a little muscle?
Well, firstly that there really isn’t much evidence that protein supplements will help. Unless your diet is at the moment extremely low in protein, chances are you’re getting enough already. The evidence suggests that most people probably don’t need a protein supplement to build a bit of muscle.
Perhaps more importantly, if your goal is general fitness or being able to actually lift more, there’s very little evidence at all that protein supplements can help. If you’re beginning your fitness journey, or are getting serious, it’s probably best to talk to an expert — probably a personal trainer or exercise physiologist — to help get your diet right.
If you’re an elite athlete, or are already eating 200grams of protein a day, taking a protein supplement is a fair way to add a bit more protein to your diet.
But for the average person? For you and me?
Chances are they just aren’t adding anything important at all.
*Note: the evidence isn’t necessarily any better for elite athletes and protein powders, but to avoid confusion I’m avoiding them. Their energy needs are vastly different to the average person.
**3 Scrambled eggs on toast for breakfast, egg salad sandwich for lunch, roasted chicken thighs on butternut squash mash for dinner with apples as snacks throughout the day