Primary school children who ate midday meals over an extended period were shown to have significantly better learning outcomes, according to researchers of Indian-origin.

The researchers, in the study published in the Journal of Development Economics, suggest a powerful connection between nutrition and education.

The study showed that children with up to five years of midday meals had reading test scores that are 18 per cent higher than those of students with less than a year of school lunches.

In addition, they showed an improvement of nine per cent for maths test scores.

"The effect of nutrition appears to be cumulative, seen over time. Previous studies have varied between two weeks and two years, and failed to capture the important impact. Our research shows that the real benefit of school lunches was seen in children exposed for two to five years," said Jayaraman.

For the study, the researchers used data from nearly 600 rural districts in India, covering over 200,000 households.

In 2017, World Food Programme implemented or supported school feeding programmes for 18.3 million children in 71 countries.