One in three children in Peru was growing up too short for their age, stunted by a lack of the right foods in their diet.

Then in 2005, the government put in place an innovative new system. They gave cash hand-outs to poor mothers but only on the condition that they had regular health check-ups and their children went to school.

By 2014 the number of children growing up too small had halved.

World Hacks tells the story.

Presented by Sahar Zand.

Image caption: Mother and child part of the malnutrition programme / Image credit: BBC