We’re led to believe the more protein the better when it comes to building muscle and losing weight. But are protein supplements, bars, and shakes helping or backfiring?
In the early 20th Century, Arctic explorer Vilhjalmur Stefansson spent a collective five years eating just meat, with a diet of around 80% fat and 20% protein. In 1928, he repeated the experiment at New York City's Bellevue Hospital. In both cases, he became ill when eating lean meats without fat, developing 'protein poisoning' or 'rabbit starvation'. His symptoms disappeared after lowering protein and raising fat intake. He later returned to a low-carb, high-fat, high-protein diet until his death at 83.
Despite soaring sales of protein supplements, many are unsure how much protein they need. Adults who aren't especially active are advised to eat roughly 0.75g of protein per kilogram of body weight daily – about 55g for men and 45g for women, or two palm-sized portions of meat, fish, tofu, nuts or pulses. Not getting enough can lead to hair loss, skin breakouts and muscle loss, but these effects are rare, mostly in those with eating disorders.
Protein is essential for growth and repair. Strength exercise breaks down muscle protein, and leucine, an amino acid, triggers protein synthesis. Supplement brands advise protein shakes post-workout, often leucine-rich whey protein. A 2022 analysis found a relationship between protein powder consumption and gains in lean body mass and lower body strength, but not for other strength tests or sore muscle relief.
However, many experts argue that inflated protein foods are a waste of money. A 2017 Mintel survey found over half of protein bar and shake users struggle to tell if they have effects. Most people already get enough protein from their diet, and extra supplements may be unnecessary.
