The growing consumer obsession with high-protein diets could drive up the cost of infant formula, as soaring demand for whey protein puts pressure on manufacturers, industry experts have warned.
The trend, dubbed "proteinmaxxing", has fuelled a sharp increase in demand for whey protein, a key ingredient used in protein shakes, bars and supplements. Demand has also been boosted by the growing use of GLP-1 weight-loss drugs, with users seeking to maintain muscle mass while losing weight.
However, whey protein is also a vital ingredient in infant formula, where it is used to replicate the protein composition of human breast milk and improve digestibility, particularly in formulas designed for newborns and babies under one year of age.
According to global market intelligence platform Expana, prices for whey protein concentrate 80 (WPC80), which contains 80 per cent protein, have more than doubled over the past year. The ingredient rose from €11,733 (£10,050) per metric tonne in July 2025 to €25,875 per metric tonne.
The sharp increase in ingredient costs has raised concerns that infant formula manufacturers may soon have little choice but to pass higher costs on to consumers.
Office for National Statistics data already shows the average price of a 750g pack of infant formula has increased by 4.8 per cent over the past year, rising from £11.55 to £12.11.
Dr Vicky Sibson, director of the independent public health nutrition charity First Steps Nutrition Trust, warned that continued increases in whey prices could further inflate formula costs.
"Whey is a major ingredient in infant formula, so significant increases in its price risk increasing the price of formula itself," she said.
She added that previous investigations by the Competition and Markets Authority (CMA) found manufacturers had passed rising production costs directly on to consumers, including during the cost-of-living crisis.
Sibson described the prospect of further price increases as "hugely concerning", citing evidence that many families already struggle to afford infant formula.
"There is mounting evidence that many families using formula to feed their babies find it unaffordable, and the coping strategies they use – like watering down feeds – may be harmful," she said.
She reiterated calls for government intervention, pointing to the CMA's recommendation that ministers consider introducing a mandatory price or profit cap for infant formula manufacturers.
"There is precedent for this from other countries including Greece and it's warranted because the CMA's work exposed high profit margins of between 50 per cent and 75 per cent. Companies should not be allowed to protect their margins at the expense of the wellbeing of mothers and babies," Sibson said.
Jose Saiz, European dairy market analyst at Expana, said rising ingredient costs have already filtered through to a range of dairy and nutrition products, although the extent of price increases varies between markets and brands.
He added that many infant formula manufacturers have begun reformulating products to reduce their reliance on expensive whey protein concentrates.
"Over the past six months, many manufacturers have reformulated their recipes in response to rising ingredient costs," Saiz said.
"One of the main responses has been to increase the use of demineralised whey powder 90 (D90), an ingredient used primarily in infant formula."
D90, which has 90 per cent of its minerals removed, enables manufacturers to achieve the required whey-to-casein ratio while also providing lactose and whey proteins. However, growing demand for the ingredient has also pushed up its price.
Saiz warned that current whey protein prices are becoming increasingly difficult for manufacturers to absorb.
"Infant formula manufacturers report that current high whey protein prices are becoming economically unsustainable at existing retail price levels. Many believe further consumer price increases will eventually be necessary unless raw material costs ease," he said.