Annual food prices have shot up faster than at any time in 13 years.

The 8.3 per cent leap last month compared with August 2021 was the biggest annual increase since the Global Financial Crisis in July 2009.

After Stats NZ released the new data, politicians moved quickly to assign blame. But an economist said a set of influences had coalesced to create a perfect storm for food prices.

ANZ chief economist Sharon Zollner said because New Zealand was a major food exporter, higher global food prices typically benefited the country.

But the benefits were not dispensed evenly, and Zollner said people on low incomes would be hurting.

Year on year, fruit and vegetable prices in New Zealand increased 15 per cent. Meat, poultry and fish were up 7.6 per cent compared to August last year.

Non-alcoholic beverage prices increased 4.1 per cent and restaurant meals and ready-to-eat food prices increased 6.5 per cent.

Food prices also rose more than 1 per cent compared with last month - up 0.9 per cent even after seasonal adjustment. Fruit and vegetable prices alone jumped 4.1 per cent last month, up 2.3 per cent even after seasonal adjustment.

Seasonal adjustment basically took into account the fact some products invariably had price spikes in certain months.

Meat, poultry, and fish prices rose 1.2 per cent last month.

Ingredients may include Putin, wages, bad weather

If you wondered why your wallet was hurting, you could - depending on your political leanings - blame one or two causes, or even one or two people.

But Zollner said the causes were much broader than any domestic influence alone. And some timeframes involved were much wider than our domestic electoral cycle.

Russia's invasion of Ukraine had sent grain exports into turmoil.

"Grain is an input into dairy and meat production globally," Zollner said. The volatile cereal prices had contributed to some food prices increasing globally.

Freak weather could also wreak havoc with already-volatile fruit and vegetable prices.

"Weather has been a big part of it, particularly in fruit and vegetables. We had an extremely wet July and August," Zollner said.

More Kiwis were leaving the country after years penned up and a sclerotic border reopening process was yet to get new migrants in to ease pressure on employees desperate for workers.

"The agricultural sector is reporting the highest wage growth across the whole economy, perhaps because they had been more reliant on imported labour than other sectors," Zollner said.

People were also paying more for groceries because throughout the production and supply chain - from workers to packers to drivers to shelf-stackers - wages and costs were rising.

Fuel was another volatile component, influencing shipping and road transportation costs.

But a much longer-term global phenomenon was at play too, Zollner said.

The global human population was now estimated at 8 billion, and many of the planet's arable lands and other agriculturally productive areas were under frequent strain.

Zollner said some measures of food production progress made in the Green Revolution after World War II had slowed.

And food waste and environmental degradation undermined gains made elsewhere.

"Now it's pretty clear that we're within the environmental limit and the world is going to face challenges feeding itself," she said.

Satish Ranchhod, Westpac senior economist, said the 8.3 per cent annual food price increase was partly the outcome of poor growing conditions.

"However, the pressure on food prices has been widespread, with shortages of many items globally, as well as large increases in production costs including fuel, fertiliser and packaging materials," he added.

"We've also seen shortages of labour and related sharp increases in wage costs."

Ranchhod said the labour crisis pushed up production costs, especially for restaurants and takeaway outlets.

And worker shortages hampered the harvesting of produce and meat processing, he added.

The Act Party said the Labour Government and Prime Minister Jacinda Ardern had not addressed price hikes.

"The world's first Instagram PM is clueless when it comes to dealing with these real-world issues, and Kiwis are paying the price," Act leader David Seymour said.

"The problem is the Government's war on businesses and relentless borrowing and spending has fuelled domestic inflation, which has crept into our most productive sector."

He said the 8.3 per cent year-on-year jump was even higher than the consumer price index (CPI) increase rise of 7.3 per cent in the June quarter.

"When a food superpower like New Zealand has record food inflation, higher than the CPI, we can definitively say inflation is a local problem, caused by Labour's economic mismanagement," Seymour added.

He said New Zealand had to become more productive by tackling the labour shortage.

"Foreign workers should be able to work for accredited employers so long as they are employed consistent with New Zealand law."

The Green Party said the Government should urgently increase support for people struggling to pay for food.

Party commerce and consumer affairs spokesman Ricardo Menéndez March said an inequality crisis was under way.

"The first step the Government needs to take is to immediately boost people's incomes, including those who rely on benefits to make ends meet," he said.

"The Green Party is clear that everyone should have an income that is enough to pay the bills and live a good life."

Ricardo Menéndez March said even before current cost of living pressures, tens of thousands of families were being forced to go without basic necessities.

Today's stats followed months of rotten news for consumers.

Last month, the StatsNZ data showed fruit and vegetable prices shot up by 10 per cent in just one year.

In June, annual food price inflation was 6.8 per cent.

Earlier in the year, cheddar cheese, milk and eggs were big contributors to soaring grocery bills.

Some economists in recent weeks have told the Herald inflation had probably peaked. Data on the country's GDP is due out on Thursday.