Have a go at this teaching activity, which includes a downloadable worksheet and suggested answers

Prices rise as demand for protein soars.

Protein powders and shakes have become a mainstream purchase for gym-goers, dieters and health-conscious shoppers. Food manufacturers now add protein to yoghurts, bagels and even water.

Demand also comes from people taking weight-loss injections such as Wegovy and Mounjaro, to help preserve muscle while eating less.

Supply has not kept pace. Producing high-protein whey requires specialist processing equipment, and European wholesale prices for some whey products have more than doubled over the past year.

One brand’s 4.5kg bag of whey protein cost around £60 in 2020, rose to £120 last year, and now costs £170. Some gym-goers have nicknamed this “proteinflation”.

Sports nutrition company Warrior has raised its shelf price from £12.50 to £17.99 and launched a new product using cheaper, non-whey sources of protein costing around half as much to produce.

Not all consumers are reacting the same way and price elasticity of demand can vary sharply between market segments. Long-term users are continue to buy, though some are switching to cheaper brands. Budget-conscious students are cutting back or stopping purchases altogether.