New Zealand should adopt stricter World Health Organisation criteria to halt the advertising of unhealthy foods to children and help address obesity, researchers say.

The Auckland University team checked a database of 13,066 packaged foods and found that more were considered "healthier" options under New Zealand's Health Star Rating (HSR) system than under the WHO's criteria to allow foods that can be promoted to children.

Three and a half stars or more on the 5-star scale can be considered "healthier", they say. Overall, 36 per cent of the foods were in that category, while only 29 per cent qualified as "permitted" by the WHO for advertising to children.

The disparity was much greater for many sweet foods, such as 12 per cent of biscuits in the star system, in contrast to just 0.3 per cent for the WHO; 77 versus 34 per cent of breakfast cereals; and 44 versus 1 per cent of dried fruits.


The Health Ministry's food and beverage classification system (FBCS) was also less restrictive than the WHO's.

"The HSR and FBCS systems would permit marketing of a number of food products of concern, particularly high-sugar breakfast cereals, fruit juices and ready meals," say Professor Cliona Ni Mhurchu and colleagues, reporting their findings in today's NZ Medical Journal.

They did the study to inform the Advertising Standards Authority's review of the code of advertising food to children. They recommend using the WHO system.

"Given the recognised weak nutritional standards employed by industry for defining healthy foods and because many child-oriented food marketers do not participate in self-regulation, the new children's code ... should be subject to evaluation by an independent body.

"If the revised voluntary code still proves ineffective in reducing New Zealand children's exposure to the marketing of unhealthy foods and drinks, additional policy and regulatory actions will be necessary."

The star system takes into account factors such as fruit, vegetable and legume content - as well as the standard nutrient categories such as fat, salt and sugar - "and these positive constituents can offset the negative components in the total score".

The major food category differences between the three systems - in breakfast cereals, fruit bars, fruit/vegetable juices and dried fruit - "appear to be due mainly to the different weighting that each system gives to sugar, with HSR in particular and FBCS to a lesser extent, notably more lenient in classifying more high sugar products as eligible/permitted."

Association of Advertisers chief executive Lindsay Mouat said the WHO criteria were "aspirational".

"They set the benchmark very high deliberately. Industry does not dismiss the WHO criteria out of hand but by WHO Geneva's own admission, they are 'tough and aspirational' which is why you don't see them being adopted.

"Critically, you cannot ask industry to reformulate their products, take out fat, salt and sugar and then forbid them from marketing the 'better-for-you' version, which is what the WHO classification does. Innovation, reformulation and marketing go hand-in-hand. We are all looking to induce consumer behavioural change; that means slowly weaning consumers onto healthier options."


The Food and Grocery Council declined to comment on the research, referring the Herald to its submission on the code review, which says the code is working well.

The code reflects the "high standards for responsibility by the industry that ensure parents' and children's trust and protection for the benefit of all of the community".

The council recommended reducing the age group to which the code applies, to under 12, from under 14 at present.