Global Malnutrition

Most countries in the world are facing a serious public health problem as a result of malnutrition, a report warns.

The Global Nutrition Report said every nation except China had crossed a "malnutrition red line", suffering from too much or too little nutrition.

Globally, malnutrition led to "11% of GDP being squandered as a result of lives lost, less learning, less earning and days lost to illness," it added.

The findings follow on from last year's Nutrition from Growth summit in London.

At the 2013 gathering, 96 signatories made "significant and public commitments to nutrition-related actions" and this report was an assessment of the work that still needed to be done and the progress made.

"Malnutrition is an invisible thing, unless it is very extreme," explained Lawrence Haddad, co-chairman of the independent expert group that compiled the report.

"This invisibility stops action happening but it does not stop bad things happening to the children, " he told BBC News.

"It does not stop preventing the children's brains from developing; it does not stop their immune systems from not developing.

"It is a silent crisis and we are trying to raise the awareness of the extent of malnutrition and the damage it does."

The UN World Food Program estimates that poor nutrition causes nearly half of deaths in children aged under five - 3.1 million children each year.

Dr Haddad, a senior research fellow for the International Food Policy Research Institute, highlighted three areas that the report focused on.

"The first thing we did was to say that we were not just going to focus on under nutrition, which is

closely related to hunger, but also over nutrition and obesity," he explained. "Malnutrition just means bad nutrition."

The second thing we did was focus on not just the outcomes, we also focused on the drivers. We looked at underlying factors, such as sanitation, water quality, food security, spending on nutrition and women's status.

"The third thing we did was to look at a very specific set of commitments that were made in the 2013 summit that David Cameron hosted in London."

The expert group's assessment on global nutrition drew a number of conclusions.