Sykes cites a Fortune column:
Here are the 6-month price percentage moves in some of the things people need to live with:
Sugar = +82.6%
Corn = +59.0%
Coffee = +41.4%
Rice = +40.5%
Oats = +36.6%
That's not the worst news. For THAT, we turn to Ritholtz:The chart illustrates how the lower income groups in the U.S. really get squeezed when food and gas prices rise. In the U.S. the average annual income for the consumer units (households) measured is $62,857, where food expenditures consume a little over 10 percent of income
...Almost one third of the households in the U.S. spend close to or more than 20 percent of their annual income on food.
(Chart at the link)
IOW, when food inflation occurs, it does not 'hit' the upper-income class. It bothers the middle-income class.
And it is VERY serious for the lower income class.