Inflation hit a 21-year high yesterday, with petrol prices and last year's GST rise pushing the consumer price index (CPI) up 5.3% during the last year.
Statistics New Zealand said the CPI increased 1% for the June quarter with the cost of food playing a major role.
Food prices increased 1.1% in that period, with grocery up 1.5%, and vegetables up 6.7%, including tomatoes which shot up 63.6% because of the Queensland floods, and lettuce which jumped up 30.1%, while fruit prices dropped 9.2%.
However, Associate Prof Parnell expected the overall rise to have "not much" effect on the average diet.
She believed much of the increase came down to imported tomatoes and capsicums, and lettuces with high price tags.
"Why do we have to eat tomatoes in the middle of winter?
"I would be very sorry if, in Dunedin, we were dependent on imported, out-of-season, food from Queensland.
"In general, I do worry about food costs for people on fixed incomes, and I would like fruit and veges to be a little bit more affordable, but I think we can make choices."
Associate Prof Parnell's biggest worry was the price of dairy products, but when it came to fruit and vegetables, she advised people to eat seasonally.
It appeared yesterday many shoppers were taking her advice.
Those spoken to had changed their eating and shopping habits.
Donna Courtney said tomatoes used to be a staple in sandwiches, but at "totally ridiculous prices", she no longer bought them.
They had started growing a few more vegetables at home and she had started hunting for bargains and opting for generic brands to cut costs.
"I really look for a bargain. There are some prices I refuse to pay."
She will no longer pay more than $10 for cheese, will buy discounted meat and freeze it, and prefers to visit the supermarket a few times a week to ensure she buys what she needs and nothing goes to waste.
Rachel Hilton was also changing her grocery shopping habits and said she found it "difficult" yesterday.
Milk and butter were expensive, she had stopped buying tomatoes, and treats such as biscuits were getting harder to afford.
When she moved from England to New Zealand six years ago, she was surprised at how far her dollars stretched.
A trolley load of groceries would cost about $200, but now that amount only filled one-quarter of a trolley, she said.
