The term ultra-poor was coined in 1986 by Michael Lipton of the University of Sussex. It is defined as “a group of people who eat below 80% of their energy requirements despite spending at least 80% of income on food”. The majority tends to be landless rural women.
It is difficult to say how many people in the world today fit this definition, but it’s likely in the hundreds of millions. About 162 million people live in “ultra-poverty,” defined as living on less than 50 cents a day, with an additional 323 million living in “medial poverty”, defined as living on between 50 and 75 cents a day, according to a 2007 report from the International Food Policy Research Institute, based on 2004 data.