High-protein eating has become something of a craze. As ‘high-protein’ claims continue to ratchet up, analysts are predicting $50.2bn (€44.3bn) of growth between 2023 and 2028. For more dedicated consumers, diets such as keto and paleo continue to drive up protein consumption.
There’s no doubt that protein is an essential part of a healthy diet, and consuming products containing a lot of it can have benefits. But, like with everything (even water), there’s an upper limit to how much protein is healthy to consume.
What is this upper limit? And what happens to those consuming too much protein?
How much protein is safe to consume?
The amount of protein you should consume, according to the UK’s National Health Service, depends on your body weight.
For example, if one weighs 55kg, they should consume between 66g-82.5g per day; if they weigh 70kg, they should eat 84g-105g per day; and if they’re 85kg it’s 102g-127.5g of protein for them.
These recommendations are far from universally agreed upon, and some experts, according to Harvard Health, suggest that commonly accepted numbers are far too low. They think we should be having a lot more.
But when does this all get too much? Giving specific amounts is difficult, according to Harvard Health, as many experts are still uncertain. Nevertheless, it suggests for people who are not professional athletes to keep protein intake below 2 g/kg of ideal body weight.
People who want to maintain a high protein diet are recommended to ensure they have no medical conditions (such as kidney disease) that can put them at a higher risk, and keep to healthy protein sources like fish, yoghurt, nuts and beans.
What are the dangers of consuming too much protein?
While protein is generally good for the health, it’s worth acknowledging that risks of overconsumption do exist.
High intake of dietary protein can have a negative effect on kidney health, according to one study, A very high protein intake, it says, can affect the kidneys, potentially leading to kidney hyperinflation, excessive protein in the urine, and even chronic kidney disease if the intake is long-term. Those with preexisting conditions are more at risk.
According to the study, animal protein is more likely to lead to end-stage kidney disease than plant-based protein, and the keto diet has been linked to the formation of kidney stones.
Some research even points to a risk of heart disease from protein overconsumption.
Some amino acids, which are the building blocks of protein, have the potential to lead to cardiovascular disease right down at the cellular level of the blood through a “signalling mechanism”, research published in Nature Metabolism claimed.
Specifically, cells that are responsible for clearing away debris in blood vessels are signalled by an amino acid commonly found in animal protein called leucine. Excessive consumption of animal protein can cause these cells to become overactive, leading to a hardening of the arteries and, in some cases, heart disease.
According to the study, getting more than 22% of daily calories from protein carries more risk than benefit.