A new report says calamitous famines appear to have vanished and hunger levels are declining but 795 million people don't get enough to eat.

The 2015 Global Hunger Index published Monday says hunger levels remain serious or alarming in 52 of 117 countries scored, with armed conflicts that cause refugees the main culprit.

The people most hungry in the world live in sub-Saharan Africa, in Chad, Central African Republic and, surprisingly, in relatively peaceful Zambia, according to the report.

It says: "While the end of calamitous famines (which kill 1 million or more) is a tremendous achievement, our work is not done. Much more must happen before acute and chronic hunger can be conquered."

The report is jointly published by the International Food Policy Research Institute, Concern Worldwide and Welthungerhilfe.