Record wheat production is expected in 2008, the FAO said.
The amount of money being spent globally on importing food is set to top $1 trillion (£528bn) in 2008, an influential report estimates.
Soaring food prices are the cause of the huge bill - likely to be up 26% on the 2007 total - said the UN's Food and Agriculture Organization (FAO).
The most economically vulnerable countries will bear the biggest burden, the report said, with costs rising 40%.
But the FAO said there were signs that some food prices were starting to fall.
However, it said prices were "unlikely" to return to the low levels of previous years - largely because of the higher costs associated with food production, primarily fuel.
The need to replenish stocks and the expected greater consumption - or utilisation - of crops, meant that demand would stay high, the report added.
"The most influential development in pushing up international prices of basic food has been the low level of exportable supplies resulting from utilization outstripping production for several crops in a number of major exporting countries."
In its analysis, the FAO said that developing countries have felt the cost of food inflation far more than wealthier nations.
"Rice has caught the headlines in recent weeks, but from dairy to wheat and soybeans to sugar, price spikes and market volatility appear to have become more the norm than the exception," the report said.
"Soaring food prices have led to serious difficulties, especially for vulnerable population groups that spend a substantial part of their incomes on food."
The FAO said that although a number of factors were pushing costs higher, there also was a chance of declines in food prices in coming months as the market adjusted to imbalances.
A huge increase in planting wheat - as growers were tempted by high returns - meant the 2008 harvest was likely to be a record, the FAO said.
This has helped bring down prices in recent weeks, though it warned that any unexpected fall in production could leave the market in a "precarious situation".
It also forecast that rice prices may fall, especially if governments are encouraged to lift trade restrictions because of bumper crops.