A university researcher says GST should be removed from fruit and vegetables to allow healthy eating targets to be more easily met.
Massey University's Emma Dresler-Hawke said a study showed the cost of eating at least five servings of fruit and vegetables per day bought at various supermarkets ranged from $1.13 to $2.12 per person, depending on the supermarket and the season.
This meant an average family of two adults and two children could spend $59.36 a week on fruit and vegetables during winter, something some lower income families could struggle to meet.
"Some studies have found that higher fruit and vegetable consumption was associated with higher diet costs," Dr Dresler-Hawke said.
"Low income groups generally have a more restricted food budget so fruit and vegetables may be overlooked in favour of more energy-dense foods."
Dr Dresler-Hawke recommended lifting GST on fruit and vegetables and providing free fruit to all school children.
"There is also considerable public support for both these measures," she said.
"The International Social Survey Programme role of Government survey in 2006 found that 87.5 per cent supported removal of GST on fruit and vegetables, and 82 per cent supported providing fruit to schoolchildren."
Dr Dresler-Hawke surveyed prices at New World, Pak'N'Save, 4 Square, Countdown and Woolworths once in each of the seasons.
Costs of meeting the five plus a day recommendation per person were cheapest in summer, ranging from $1.13 to $1.98. Winter was most expensive at $1.64 to $2.12 per person, while prices ranged from $1.40 to $1.97 in spring and from $1.37 to $2 in autumn.
Dr Dresler-Hawke excluded some fruit and vegetables she regarded as exotic, such as bok choy, guavas and lychees, concentrating on more common varieties. Potatoes and other root vegetables were also excluded because most countries do not include these as servings of vegetables.
She said consumers could pay less if they bought some cheaper processed food.
"Research has indicated that fresh, frozen and canned fruit and vegetables are nutritionally comparable."
Dr Dresler-Hawke's research is presented to an Australia-New Zealand marketing conference in Dunedin tomorrow.