A Moody’s report last month estimated the average family was spending $250 more per month due to excess inflation, even before the new monthly figures.

Threat level: Low-income households are especially vulnerable despite wage increases.

For a family of four on a “thrifty” budget, food cost an average of $863 in December, up from $671 a year earlier, according to the most recent figures published by the Department of Agriculture.

Real average weekly earnings — a figure accounting for inflation’s impact — fell 3.1% in January, compared with a year earlier.