Greggs profits hammered by Britain's fat jab obsession as habits shift from pastries and cakes

She said customers are increasingly opting for smaller portions rather than the larger products traditionally associated with the brand.

Ms Currie said the shift is not only about eating less, but also about changes in the types of food customers are seeking.

She said shoppers are showing greater interest in products containing protein and fibre alongside generally healthier options.

Greggs has been adjusting its menu to respond to this change in demand.

The comments came alongside the company’s latest financial results, which showed weaker profits and a more cautious outlook for the year ahead.

Ms Currie said the changes in eating habits form part of a broader health trend that is influencing purchasing decisions across the food sector.

She said protein has become a particular focus for customers seeking more balanced snack options.

Greggs has been working to develop products aimed at customers using GLP-1 weight loss medications.

In July, the company announced plans to introduce smaller snack options and products with higher protein content to appeal to this group.

One of the products introduced as part of this strategy was an egg pot, which was launched alongside the company’s “eggs at Greggs” advertising campaign.

Ms Currie said: "We need to make sure that we’ve got some of the snack products that customers are looking for if they are on any of the GLP-1 drugs."

She said the company’s product development reflects changing expectations around portion size and nutritional content.

The shift represents a notable change for a brand best known for items such as sausage rolls and steak bakes.

Greggs has previously said that evolving dietary preferences are leading customers away from traditional high-fat pasties, cakes and pastries.

The company said it continues to balance its core product range with new options designed to reflect changing lifestyles.

Greggs is not the only major retailer to highlight the impact of healthier eating trends.

Tesco said a move towards healthier diets has contributed to stronger sales of fresh produce.

The supermarket’s chief executive, Ken Murphy, said the company is closely monitoring customer behaviour as the use of weight loss medication becomes more widespread.

He said Tesco has expanded its range of products designed to appeal to customers using GLP-1 medications.

"Clearly our strongest source of growth this year has been in fresh food, and that is, by far and away, the best thing people can eat."

Mr Murphy said the retailer also offers a wide range of high-protein products across different categories.

He added: "I think we’re well set to respond to any trends in healthier eating."

Analysts have also been assessing the potential impact of weight loss medications on food consumption.

Clive Black, consumer analyst at Shore Capital, said a slight fall in grocery volumes over the Christmas period compared with last year could be linked to changing eating habits.

This could be “perhaps the clearest indication of the impact of glucagon-peptide drugs upon the nation’s eating habits”, he said.

Reduced consumption could have implications for food retailers over the longer term.

Industry observers have also noted that smaller portion sizes are partly being influenced by cost pressures.

Some manufacturers have reduced product sizes while keeping prices unchanged as a response to higher ingredient costs.

Separately, a new restriction on junk food advertising before 9pm has recently come into force across the UK.

The ban forms part of Government efforts to address rising obesity levels and improve public health.