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In the early 20th Century, Arctic explorer Vilhjalmur Stefansson spent a collective five years eating just meat. This meant that his diet consisted of around 80% fat and 20% protein. Twenty years later, he did the same as part of a year-long experiment at the New York City’s Bellevue Hospital in 1928.
Stefansson wanted to disprove those who argued that humans cannot survive if they only eat meat. But unfortunately for him, in both settings he very quickly became ill when he was eating lean meats without any fat. He developed "protein poisoning”, nicknamed “rabbit starvation”. His symptoms disappeared after he lowered his protein intake and he raised his fat intake. In fact, after returning to New York City and to a typical US diet with more normal levels of protein, he reportedly found his health deteriorating and returned to a low-carb, high fat, and high protein diet until his death aged 83.
His early experiments are some of the few recorded cases of high protein intake having extreme adverse effects – but despite soaring sales of protein supplements, many of us are still unsure how much protein we need, how best to consume it, and if too much, or too little, is dangerous.
Despite obesity rates doubling over the past two decades, we’re becoming increasingly conscious of what we’re eating. In recent years many of us have swapped white bread for brown and wholemeal bread and full-fat milk for skimmed. Taking centre stage in our health kick is protein, with protein balls, bars and enhanced protein versions of staple products, from cereals to soup, dominating supermarket shelves. And with the global protein supplements market valued at $12.4bn (£9.2bn) in 2016, it’s clear we’re buying into the idea that we need as much protein as possible.
But some experts now argue that foods with inflated protein (and prices) are a waste of money.