The Food and Agriculture Organization (FAO) food price index, which tracks the monthly change in international prices of a basket of food commodities, has been falling steadily since hitting an all-time high in March following Russia's invasion of Ukraine.
There was a moderate decline of 1.9 percent in August.
Vegetable oils have fallen below their level a year ago, after a 3.3 percent drop.
The FAO cereals index fell by 1.4 percent, driven by a 5.1 percent drop in international wheat prices.
It came off the back of "improved production prospects in North America and Russia as well as the resumption of exports from the Black Sea ports in Ukraine for the first time in over five months of interruption", the FAO said.
Global wheat prices were still 10.6 percent above their values in August last year, the FAO said.
Exports from Ukraine -- one of the world's biggest suppliers of wheat, corn and sunflower oil before the war -- had ground to a trickle due to a Russian blockade of the Black Sea.
The shipments resumed in early August under a deal brokered by the UN and Turkey.