Government definitions of "poor" don't necessarily equate to what you and I would call "poor," due to politics (basically, getting more people identified "poor" helps you get votes if you're the party perceived as better able to help the poor, and in the US one party has dominated the poverty issue and used this strategy for a number of decades).

For example, someone I knew in high school (a number of years ago now) qualified for the school lunch program, so nominally his family was poor. But they lived in a house, with a yard; had cable TV, computers, and Internet. I would say they're working-class, or maybe even lower middle-class.

If the lowest-income 20% of the population is labeled as poor for the purposes of this statistic ("nominal poor"), but the number of people who are so poor their children are starving in the streets ("desperately poor") is 0.20% of the population, then it's not so surprising that statistics over the nominal poor much more closely resemble the general population than the picture of the desperately poor.