The Government must consider new data suggesting people continue to spend more to provide even a basic standard of nutrition for their families, a University of Otago nutrition specialist says.
The university's Department of Human Nutrition's Food Cost Survey 2010 confirms people spent more on even the cheapest shopping trip than they did the year before.
The annual survey of prices in Dunedin, Christchurch, Wellington, Hamilton and Auckland also found Dunedin was no longer the cheapest city for a basic diet - a change that a new slew of costs might make hard to shake.
Human nutrition Associate Prof Winsome Parnell said last night Dunedin's change in fortunes might be linked, in part, to the rising cost of fuel and its effect on transporting food to regional centres.
The next survey, on the first Monday of March, would probably also reflect the cost of the Emissions Trading Scheme and higher GST.
The Government should consider the findings alongside the once-a-decade national nutrition survey, to be released next year, when it considers tax and develops social policy.
"Inevitably, the rising cost of food will mean a greater proportion of people will not afford to eat well, and that has a significant personal and social cost," the Dunedin-based researcher said.
The survey found Dunedin was the third-least expensive place to buy a week's worth of "basic" groceries for a household of two adults, an adolescent boy and a girl.
The basic shopping list included most commonly consumed meats, fish, fruits and vegetables.
The survey assumed all were prepared at home.
It found it cost an estimated $267 for the basics in Dunedin, $263 in Christchurch and $265 in Hamilton.
Last year, it found it would cost $252 for a basic diet in Dunedin, $256 in Hamilton and $259 in Christchurch.
The Dunedin diet cost $212 in 2004, when the cheapest place was Hamilton ($208).
Moderate and liberal shopping lists were also measured.
Dunedin was the second most expensive in both categories ($347 moderate and $416 liberal).
It cost $343 for a moderate list in Christchurch and Hamilton, $353 in Wellington and $356 in Auckland.
A liberal list cost $426 in Auckland, $425 in Wellington, $412 in Hamilton and $411 in the cheapest centre, Christchurch.
The survey, a snapshot of prices at four supermarkets in each city, was undertaken in March.
