The rise in commodity costs could spark a “structural change” in the US food industry, according to debt rating agency Fitch.

The higher prices of agricultural commodities may raise long-term costs at US food makers, leading to “financial stress” for companies struggling with heavy debt.

“The presence of high debt levels will always compound the effects of operating challenges that are often out of a company’s control,” said Fitch director Carla Norfleet Taylor.

Wesley Moultrie, senior director at the agency, said changes in the supply of and demand for commodities would affect costs in the long term.

“The global supply and demand dynamics for agricultural commodities may have permanently shifted, thus increasing companies’ cost structures for the long term,” Moultrie said.

In its report, Fitch cited companies including ailing US baker Interstate Bakeries Corp. and produce giant Chiquita Brands International as “fallen angels”.

The agency said that ongoing pressure from commodity costs and weaker consumer spending would reduce profitability and cash flow at “several high-yield and low-investment grade food and restaurant companies”.