The rise of “proteinmaxxing” – a trend in which consumers try to eat as much protein as possible – could lead to higher prices for infant formula, experts warn.

Whey protein, a key ingredient in infant formula, has surged in popularity over the past year as health professionals emphasise the benefits of protein.

The growing use of GLP-1 weight-loss medications, which suppress appetite, has also boosted demand for concentrated whey protein – often found in protein shakes and bars – as users seek to preserve muscle mass while losing weight.

As demand rises, so do prices. Expana, a global market intelligence platform, said whey protein concentrate 80, with 80% pure protein, cost €11,733 (£10,050) per metric tonne in July 2025 and was now at €25,875.

Whey protein is a vital ingredient in infant formula where it is used to mimic human breast milk by adjusting the protein ratio and making it easier to digest. High-whey formulas are designed specifically for newborns and babies under one year old.

Industry insiders warn that rising demand could soon be felt by consumers as infant formula manufacturers struggle to absorb higher ingredient costs. Office for National Statistics data shows the average price of baby formula has already increased by 4.8% over the past year with a 750g box now costing £12.11, up from £11.55 a year earlier.

Dr Vicky Sibson, the director of the First Steps Nutrition Trust, an independent UK public health nutrition charity, said: “Whey is a major ingredient in infant formula, so significant increases in its price risk increasing the price of formula itself.”

She added: “We know from the Competition and Markets Authority’s [CMA] report that infant formula manufacturers have passed any rise in input costs on to consumers, including during the cost of living crisis.”

Sibson said it was “hugely concerning” because of “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 a solution the CMA had proposed was for the government to impose a mandatory price or profit cap. “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% and 75%. Companies should not be allowed to protect their margins at the expense of the wellbeing of mothers and babies,” she said.

Jose Saiz, who covers the European dairy market at Expana, said: “Overall, higher ingredient costs have already led to higher consumer prices across many dairy and nutrition products, although the extent of cost pass-through varies by market and brand.”

He said some infant formula manufacturers were reformulating products to use more D90 demineralised whey powder. D90, which has 90% of its minerals removed, helps manufacturers achieve the required whey-to-casein ratio while supplying both whey proteins and lactose. As more producers switch to the ingredient, demand has risen sharply, pushing up D90 prices as well.

Saiz said: “Over the past six months, many manufacturers have reformulated their recipes in response to rising ingredient costs. One of the main responses has been to increase the use of demineralised whey powder 90 (D90), an ingredient used primarily in infant formula.”

He added: “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.”