In the wake of the decision this week by Kazakhstan, the world's fifth biggest wheat exporter, to join Russia, Ukraine and Argentina in stopping exports to satisfy domestic demand, the situation in Japan is expected to worsen.
Bakeries, forced to increase prices by up to 30% in the past year, are warning that the trend will continue. Manufacturers of miso, a culinary staple, are preparing to pass on the bump in costs caused by the rising price of soybeans and cooking oil. And the nation's largest brewer, Kirin, is lifting beer prices for the first time in almost two decades to account for the soaring cost of barley.
"In the past, Japan was a rich country with a powerful yen that could easily buy cheap imports such as wheat, corn and soybeans," said Mr Shibata, who directs the Marubeni Research Institute in Tokyo. "But with enormous competition from the booming Chinese and Indian economies, that's changed forever. You also need to take into account recent developments, including the damage to crops caused by drought and other disasters in exporting countries like Australia," where the value of wheat exports has tumbled from $3.49 billion to $2.77 billion in the past three years.
The situation has been compounded by a surge in demand for bio-fuels such as ethanol, made from maize, encouraging farmers around the world to divert their efforts away from wheat and barley and into maize, further driving up prices.
Arguably Japan's biggest concern, however, is its weakening ability to sustain its population with domestic produce. In 2006 the country's self-sufficiency rate fell to 39%, according to the Agriculture Ministry. It was only the second time since the ministry began keeping records in 1960 that the population derived less than 40% of its daily calorie intake from domestically grown food.
Shinichi Shogenji, dean of the University of Tokyo's graduate school of agricultural and life sciences, said Japan's meat consumption had increased by 900% since 1955, in part because expanding incomes had enabled families to supplement the sparse national diet of rice, fish and miso soup with more Western-style food.
This trend, combined with rapid ageing and declining rural populations, had placed the country's self-sufficiency at a perilously low level, Professor Shogenji said.
In view of recent predictions by Goldman Sachs analysts that commodities could experience "explosive rallies" in the next two years, many are wondering if Japan could become an example to other rich nations that have relied too much on foreign supplies to put food on their tables.