Absolute Poverty
Absolute Poverty is a condition characterised by severe deprivation of basic human needs, including food, safe drinking water, sanitation facilities, health, shelter, education and information. It depends not only on income but also on access to services.  (According to a UN declaration from Copenhagen in 1995. Info in this section on absolute poverty from Wikipedia)

World Poverty

 In developing countries, poor and needy people spend up to 80 % of their disposable income on food.  There is no buffer to modify their food costs. Those who always lived on the edge of starvation have been tipped over that edge by spiraling prices. Economic theory known as  Engel’s Law notes that the proportion of a nation’s income spent on food is a good measure of the nation’s welfare.

This is part of an article from the July issue of Spotlight on Orphans newsletter.

Poverty in the US
The official poverty rate in the US was 12.3% for 2006. (The last year stats available for.)

The US is now in a depression and the poverty rate is probably much worse now.