A New Zealand health expert has criticised Coca-Cola's new bid to help Kiwis reduce their sugar intake saying he believes it's purely a way to pump up the company's sales and nothing more.

"Coke is there to make money for the shares of Coca-Cola, they are not there for the health of you and me and the rest of NZ," Otago Professor in Human Nutrition and Medicine Jim Mann said.

Earlier this week, it emerged Coca-Cola had ended Coke Zero and Coke No Sugar, replacing the two fizzy drinks with a new offering: Coke Zero Sugar.

A media release from Coca-Cola said the company "continues to invest in the no sugar category and in 2019 made a commitment to reduce sugar throughout its portfolio by 20 per cent by 2025."

Coca-Cola New Zealand's head of marketing Tracey Evans said the company knew there continued to be a growing appetite for no-sugar options, and one in two Coca-Colas purchased in New Zealand contained zero sugar.

"Kiwis are one of the biggest no sugar consumers globally and we're committed to reducing sugar throughout our portfolio to provide delicious options for our customers," Evans said.

However, Mann - who has been involved in the World Health Organisation's sugar intake recommendations for about 20 years - said he wasn't convinced this was a big deal.

"There are so many health things that are a big deal at the moment and this isn't really one of them."

He said there were no health benefits from non-nutritive sweeteners (sugar substitutes) and "it was as simple as that".

"There are benefits to consuming less sugar but I don't really think there is a lot of evidence that if you have these non-nutritive sweeteners that you are going to have a lot less sugar," Mann said.

He said Coke Zero Sugar could be some help to people who are severely addicted to Coke.

"But if you say to me is this going to improve the health of the nation then the answer is no," he said.

A Coca-Cola New Zealand spokeswoman today said: "We use sugar alternatives in some of our products because we know that many people want the choice of great-tasting beverages with less sugar.

"We only use sweeteners that have been thoroughly tested in scientific studies, are confirmed as safe by globally recognised authorities and which are permitted for use within New Zealand food regulations."

Coke Zero was launched in 2006, nicknamed "Bloke Coke" because of its appeals to a male market.

It was followed in 2017 by Coke No Sugar, which sold itself as being closer in taste to original Coke.