Anti-obesity campaigners believe the Labour Party has missed an opportunity to make a real dent in sugar consumption by failing to back a sugar tax on fizzy drinks.
The party has pledged to force food manufacturers to reduce the amount of sugar added to processed foods if it leads the next government, but deputy leader and health spokesperson Annette King ruled out introducing a tax on sugary drinks.
"It's a jolly sight easier to enforce a reduction of sugar in processed food than it is to try and tax some of the sugar," Ms King said.
Fight The Obesity Epidemic spokesperson Robyn Toomath said while the party's obesity plan was better than the government's policies, it was "disappointing" Labour had ruled out introducing a sugar tax on fizzy drinks.
"It's the first, the easiest, the most obvious and the least controversial thing that they could do in regard to sugar," she said.
Dr Toomath, an Auckland Hospital endocrinologist, said Labour's policy to make food producers reduce the sugar content in processed food was not new.
"The Labour party first suggested this nine years ago. Just before they lost the election to National they had a revised Public Health Act, which had in it a clause which said that voluntary codes would be agreed with industry and if after two years the agreement had not been kept then the director-general of health would have a mandate to regulate," she said.
University of Auckland professor of population nutrition and global health Boyd Swinburn said while he was pleased Labour was taking childhood obesity seriously, it was disappointing there was no mention of a sugar tax.
He said while there was strong evidence these types of taxes worked, it took guts to implement.
"One day we will get politicians brave enough to take on the food industry and institute a tax on sugary drinks.
"I'm just in California at the moment and I've just heard a whole lot of presentations on the impact of taxes on sugary drinks in Mexico and Berkeley and there is no doubt they have a clear impact," he said.
Mr Swinburn said overall Labour's obesity plan was a step in the right direction, as it was more than the current government was doing in this area, but he was waiting to see more detail on how it might work.
The Food and Grocery Council, which represented food manufacturers, said it would not comment on Labour's policy until it had more detail.
"The industry is already doing a lot of work to reduce sugar and portion sizes," said spokesperson Brent Webling.
He said there were 600 products available with the 'Health Star Rating' system, which was a voluntary front of package labelling system designed to help consumers make health choices.
Ms King supported the introduction of front of package labels which gave sugar content measured in teaspoons, rather than grams, which she said was more easily understood by the public.