While Hugh McGuire said that he still sees value in the brand, the collapse of revenue from the company which was purchased for €300m in 2018 has been nothing short of spectacular.

In 2019, the Slimfast had revenue of approximately €300m, which had dropped in half to €150m by last year.

As McGuire said, the brand popularity was built on the back of the keto diet, which, as it turned out, was a passing fad rather than a permanent shift in consumer behaviour.

McGuire did say that the Covid-19 pandemic did cause a major shift in consumer behaviour, which has been matched by a shift in how retailers display the brand.

Shelf space in the US, always a premium, has been seriously curtailed for products that are seen as diet or weight loss.

McGuire said that even in the smaller amount of space left, Glanbia’s other brands such as Optimum Nutrition and Isopure are competing. With Glanbia’s stated aim of increasing the focus on brands other than Slimfast when it comes to advertising spend, it is clear that Slimfast’s future, whatever it is at Glanbia, will be a smaller part of the company than would have been signalled when it was bought back in 2018.


Looking elsewhere in the portfolio, it does need to be noted again how much of a success the Optimum Nutrition brand has been.

Purchased a decade before Slimfast in 2008, it alone accounted for approximately 20% of Glanbia’s total revenue last year (see Figure 2). According to Glanbia, it is now the number one global brand in the sports nutrition sector.

Having the right products at the right time

For Hugh McGuire, this year’s Glanbia earnings are something he can talk about, but probably not take a huge amount of credit for as he only started in the position of CEO on January 1 2024. Therefore, the most interesting thing he told the Irish Farmers Journal is what his plans for the future are.

It is clear from talking to him that he is both passionate about the business and hugely ambitious for the future.

“I see growth potential across the board”, he said, while noting that Glanbia as it is today has been built through acquisitions.

With an active pipeline of acquisitions, the success of McGuire’s tenure may well be decided by how he deals with what Glanbia has previously purchased, both the good in ON and the not-so-good in Slimfast and what he decides to buy in future.

Glanbia is, in many ways, a company that is built on the back of consumer lifestyle choices.

The lesson from Slimfast is that those choices can change very quickly.

While Glanbia’s broad portfolio of brands means it will always see some perform better than others, it will be important for the company to make sure it continues to have the right products at the right time to meet those changing consumer demands