Malnutrition is to blame for more than half of all the deaths of children around the world - including deaths caused by diarrhea, pneumonia, malaria and measles - researchers said on Thursday.

Poor nourishment leaves children underweight and weakened and vulnerable to infections that do not have to be fatal, the team at the World Health Organization and Johns Hopkins University in Baltimore found.

They estimated that feeding all children worldwide an adequate diet would prevent about 1 million deaths a year from pneumonia, 800,000 from diarrhea, 500,000 from malaria, and 250,000 from measles.

“Malnutrition does not have to be severe to have a significant impact on child health and survival,” said Laura Caulfield, an associate professor with the Bloomberg School’s Center for Human Nutrition who led the study.

“Our analysis shows that even children who were small, but whose weight would not classify them as malnourished, were twice as likely to die as children in our reference group.”

Her group analyzed the data from 10 studies of childhood deaths around the world, and used complex formulas to extrapolate the effect of weight on the likelihood of death.

They estimate that 52.5 percent of all deaths in young children were attributable to undernourishment, with nearly 45 percent of measles deaths and more than 60 percent of deaths from diarrhea associated with low weight and poor nutrition.

“These findings underscore the need to make the improvement of the nutritional status of children a priority,” they wrote in their study, published in the American Journal of Clinical Nutrition.