Do protein supplements work, are they a waste of money and could they be dangerous? We get to the bottom of this controversial issue.
Protein shakes, powders and other dietary supplements have been touted as a silver bullet for aspiring bodybuilders looking to make epic gains in a short space of time.
But are these popular products the real deal, or are those looking to build muscle barking up the wrong tree?
In this guide, we'll evaluate the evidence and get to the bottom of whether or not protein supplements work.
Proteins are a type of molecule that's vital in helping us metabolise foods, make tissues and cells, repair damage and strengthen our bones.
When we ingest proteins, they're broken down into amino acids, which are in turn, used to make new amino acids.
Since humans can't make all the amino acids they need, it's necessary for us to get them from the foods we eat.
Protein drinks and other supplements are based on the idea that the faster proteins are broken down, the quicker they can be turned into amino acids and put to work.
In theory, this results in enhanced muscle recovery and growth particularly among the likes of athletes and bodybuilders, who subject their bodies to intense physical activity.
But whether or not they're more, or even as, effective as regular, food-based sources of protein has proved a source of contention within the scientific community.
A 2003 study looked into the effects of a carbohydrate-protein supplement on performance during exercise of varying levels of intensity and found improved levels of aerobic endurance performance (how long people could exercise for) versus both carbohydrate-only supplements and a placebo.
These results were backed up by several other studies, which reported improvements in time to fatigue for participants taking protein-carbohydrate supplements.
Similarly, drinking proteins during an extended exercise session was found to improve protein balance (how much your body is utilising versus how much it's losing).
Other studies into adding protein to carbohydrate supplements have found encouraging results, including reporting of reduced soreness after exercise (which may indicate better recovery) and improved fluid retention.
However, it's worth noting that there's little in the way of scientific evidence that indicates protein can have a direct impact when it comes to improving athletic performance, which is why promoters tend to focus on highlighting secondary benefits like these.
They don't work as advertised: A systematic analysis of popular sports products conducted by researchers at Oxford University found no evidence to back up claims that protein powders and shakes enhanced performance and recovery any more than eating a balanced diet.
These misleading messages filter down to everyday health advice by company-sponsored scientists who advise high-profile sports bodies, warned Deborah Cohen, Investigations Editor for the BMJ.
In his review of the science behind protein supplementation, Dr James Betts noted that the evidence overwhelmingly suggests there is no discernible benefit, citing nine studies that backed up this claim.
Similarly, he suggested even the theory was at fault, noting there is no empirically supported mechanism to explain why ingesting protein during exercise would be beneficial in terms of performance.
Dr Betts went on to note that while protein and amino acids had been shown to influence the rate at which your body produces protein and lean tissue, these should be ingested using whole foods, which would provide all the necessary protein, with the added benefit of a range of other nutrients.
You're probably getting enough protein in your diet: While protein supplements aren't totally without benefit, the sellers of shakes and powders rely on ignorance about how much protein people training need to push their products.
The role protein plays in building and repairing muscle is undeniable, but the fact of the matter is unless you're a professional athlete at the top of their field, you're probably getting all the protein you need from your diet.
The typical western diet is brimming with protein and you're probably in danger of exceeding your recommended intake even before turning to supplements. As a rule of thumb, it's recommended that people have about half a gram of protein per pound of body weight, with high-level athletes having about 1.2 to 1.4 grams per day, per kilogram of body weight.
And while those training should aim for a little more protein, they should usually be able to get more than enough with a few simple tweaks to their diet. Although they could opt to get extra protein through supplements, they'd be missing out on all the other nutrients available in regular food. As with many things in the world of nutrition it's not just the nutrient that matters but how it's delivered to your body.
This has been supported by several studies, including one published in the Journal of Nutrition, which surveyed 1,000 adult men at 50 gyms and found that while nearly half were taking supplements (mostly protein) without supervision, virtually all of them were already getting enough protein in their normal diet.
Supplements can kill you: Research by US organisation Consumer Reports tested 15 popular protein powders and found several contained dangerously high levels of toxic heavy metals like arsenic, lead and mercury.
Three products were found to be of particular concern with the suggested serving sizes putting users at risk of dangerous levels of exposure.
Even if you're confident that the supplement you're taking is safe the dangers don't stop there.
As we've shown above, most people don't need any more protein in their diet and consuming too much can cause a range of unpleasant problems. An excess of protein can cause diarrhoea, lead to the demineralisation of bones, increase the risk of osteoporosis (brittle bones) and exacerbate kidney problems.
Putting Paid to Protein Supplements
While the desire for a fast-track solution to gaining muscle and improving athletic performance is understandable, the evidence to date suggests protein supplements are at best ineffective and at worst pose several health risks.
Unfortunately, it seems science has yet to devise a better way of delivering the vital nutrients your body needs than nature already has. So until something more effective comes along, you're best off focusing on maintaining a balanced diet that offers all the protein you need, along with carbohydrates and other vital nutrients.