In 2010, over 17 million US households were unable to eat properly, says report.
Households living near or below the poverty line, single-parent households, and black or Hispanic households, were mostly affected, said the report from the Department of Agriculture.
Among those affected, some 6.4 million homes (5.4 percent) were particularly affected by food insecurity, said the report, facing smaller portions, unhealthy diets, hunger and weight loss.
Some 9.8 percent of households with children faced similar food insecurity, down slightly from 10.6 percent of the same demographic in 2009, the report said.
The "study underscores what we know, that the food security remains a serious problem," said USDA under secretary Kevin Concannon in a conference call with reporters.
The USDA last month noted that nearly 46 million people, or one-in-six Americans, were in April this year living with government-issued food stamps.