Rotorua budget adviser Pearl Pavitt said people needed to be smarter when budgeting for groceries.
After rent and power, food should be third on the priority list for people's expenses, Mrs Pavitt said.
Home-cooked meals and purchasing in-season vegetables would go a long way, she said.
"You're not going to buy a cantaloupe melon if apples are cheaper."
Mrs Pavitt advised people not to be drawn in by cheap sugary foods - which often cost less than healthy produce.
Monthly prices from Statistics New Zealand showed soft drinks, coffee and fruit juice prices fell by 2.6 per cent, 5.6 per cent and 6.1 per cent respectively in December.
"We have to look at the good for the children - if you're going to give children fizzy drinks and chocolate because sometimes they like rewards for good behaviour [then] it's certainly doing nothing for their health and their teeth," Mrs Pavitt said.
A study led by the University of Otago, published this week in the British Medical Journal, found the risk of obesity in children increased as more sugary drinks were consumed.
Lead authors of the study, Dr Lisa Te Morenga and Professor Jim Mann, called for a stronger focus on nutritional information targeting sugar intake. "It seems easier to overeat if your diet includes lots of sugary foods and drinks.
"When you overeat you gain weight," Dr Te Morenga said.
Statistics NZ price manager Chris Pike said the monthly decline in non-alcoholic beverage prices reflected lower overall food prices last month.
Prices were down 0.2 per cent in December and 1 per cent year-on-year.
Heart Foundation national nutrition adviser Delvina Gorton said ideally she would like to see prices of fruit and veges going down to encourage people to eat more and the price of sugary drinks going up. Ms Gorton advised people to look for seasonal specials on fruit and vegetables.
In December 2011 Toi Te Ora Public Health launched the Kai @ The Right Price programme to encourage people to eat seasonable foods.
The programme was opened at Western Heights' Produce Plus store.
Shoppers are given the choice of a $10 or $15 bag packed with seasonal fruit and vegetables.
Produce Plus owner Mohan Anand said the programme was still working and people enjoyed buying a variety of food much cheaper than in the supermarket.
"We can provide them with carrots, potatoes, onions, cabbage, and in season things like broccoli, sweet corn, apples and tomatoes." He said people were more conscious about the health benefits of fresh produce.
PRICES
Fruit and vegetables up 6 per cent:
Kumara up 109 per cent
Avocado up 107 per cent
Pumpkin up 32 per cent
Apples up 20 per cent
Grocery food down 3.6 per cent:
Fresh milk down 9.4 per cent
Cheese down 8.2 per cent
Bread down 4.2 per cent
Meat, poultry and fish down 2.1 per cent:
Lamb down 24 per cent
Poultry up 2.8 per cent
Pork down 3.7 per cent
Take away pizza down 12 per cent*
Food prices - annual change to December 2012
