Protein has gone from a niche bodybuilding supplement to a mainstream obsession – and is now added to a huge range of food and drink products. What led to the sudden growth of this multimillion-dollar industry?

At the Protein Pick and Mix store in Tunbridge Wells, you can have any snack you like, as long as it comes with extra protein. Protein pancakes, protein burger buns, protein muffins, protein nachos, protein croissants. Protein bars, of course, in every conceivable flavour: caramel millionaire’s shortbread, New York cheesecake, mint chocolate chip, double chocolate fudge, lemon drizzle, cinnamon swirl. White chocolate chip cookies that incorporate something called a “high protein lean matrix”.

I am being shown around the store and warehouse by the founder, Anthony Rodgers, 36, who has the well-defined musculature of a man who regularly eats three protein bars a day. He started the business, originally as an online shop, in 2013, after observing the trend for exotically flavoured protein bars in the US. “At the time I was an avid gym-goer,” he says, “and protein bars were just starting to be a little more creative, a little more exciting. People were putting actual effort into the flavours, and it started to transcend the boring, functional: ‘we’re just going to ram some protein in you.’”