LONDON - When Katie Mulligan baked a beetroot cake for her colleagues at a London advertising agency, she was focused on getting the recipe right rather than whether it was acceptable to bring treats into the office.

But office cake culture has recently been challenged by the head of Britain's food regulator, Susan Jebb, who grabbed headlines last month by comparing it to passive smoking.

"I just don't think there's a real equivalence there," Mulligan, 30, said at her north London home. "With cakes, it's up to you whether you eat it."

With a passion to bake and cook, Mulligan says her cakes help colleagues beat the afternoon slump - and beetroot is a relatively healthy option.

Jebb, however, believes cakes in the office are an example of a society that is promoting unhealthy food choices.

“If nobody brought in cakes into the office, I would not eat cakes in the day," Jebb told The Times newspaper.

"But because people do bring cakes in, I eat them. Now, OK, I have made a choice, but people were making a choice to go into a smoky pub.”

Jebb, who was not speaking on behalf of the Food Standards Agency, made the comment days after parliament published a report that said 25.9% of adults in England were obese and a further 37.9% were overweight, citing a 2021 survey.

The United States ranked highest in the world for obesity levels with 43%, the report added citing OECD Health Statistics, while Britain as a whole, not just England, was at 28%.

The trend in the UK is "only going to get worse," said Katharine Jenner, director of Obesity Health Alliance, a coalition of over 40 organisations that tackle obesity by influencing government policy.

Obesity is costing Britain's National Health Service and the wider society something like 60 billion pounds ($72.63 billion) a year, she said.

The country needs to change its broader food culture and soon.

"I reckon we're about in the (19)60s' equivalent of sugar and diet-related ill health compared to smoking. So we've got a long way to go," she said.

At Mulligan's office, enjoying the beetroot cake and its edible flower garnishes, while striking up conversations, provides a welcome break for her colleagues and lightens up office life.

"It helps build friendships. It creates a really lovely atmosphere," said advertising strategist Bish Morgan, 26.

"As long as people are sensible and strike the right balance then yeah, I still think it's a lovely thing to do in the office." ($1 = 0.8261 pounds)

(Reporting by Vin Shahrestani; Editing by William James and Susan Fenton)