Global hunger levels rose last year for the first time in more than a decade, the United Nations said, with 11 per cent of the world's population affected as a result of conflict, climate change and economic downturns.
There were 815 million people going hungry last year, 38 million more than in 2015, five UN agencies said in the first global assessment since governments set an international target to eliminate hunger and malnutrition by 2030, as one of a set of Sustainable Development Goals.
The number of hungry began to rise in 2014, but this is the first time in more than a decade that the proportion of the global population going hungry has risen.
About 489 million of the hungry live in countries affected by conflict.
"Over the past decade, conflicts have risen dramatically in number and become more complex and intractable in nature," the heads of five UN agencies said in The State of Food Security and Nutrition in the World 2017 report.
"This has set off alarm bells we cannot afford to ignore: we will not end hunger and all forms of malnutrition by 2030 unless we address all the factors that undermine food security and nutrition."
Famine struck parts of South Sudan earlier this year, and there is a high risk that it could return there, and also develop in other places affected by conflict: north-east Nigeria, Somalia and Yemen, the UN agencies said.
David Beasley, the head of the World Food Programme described the latest figures as "an indictment on humanity".
"With all the successes of technology and wealth we should be absolutely going in the other direction," he said at the release of the report in Rome on Friday.
"We call upon the leaders of the world to apply the pressure that's necessary to end these conflicts so we can achieve zero hunger," he said.
The report was produced by the WFP, the Food and Agriculture Organisation, International Fund for Agricultural Development, the UN Children's Fund and the World Health Organisation.
The agencies called for new ways of working to achieve the goal of ending hunger and malnutrition by 2030.
"It's not only about meeting need, but also ending the need and addressing the root causes of hunger," said Zlatan Milisic, WFP's deputy director of programmes.
In war-torn countries, it means agencies need to spend more time understanding the complexities of the conflict and working towards building peace, he said.
He said the agency had a lot of research that showed food insecurity "doesn't directly lead to conflict, but it is a very powerful trigger", while food security has been as seen as a contributor to maintaining peace."
Aid can sometimes increase tensions in a community. For example, unless aid for refugees supports their hosts as well it may raise tensions with those families, who are often poor themselves with little access to basic services.
Aid programmes that create jobs, restore roads and improve farming in countries recovering from war help address root causes of conflict, the FAOsaid.
Intense and prolonged droughts can significantly increase the likelihood of conflict, according to the report. And these are expected to become more frequent with climate change.
Nearly 1,000 dead and 40 million affected by flooding in South Asia
The proportion of children stunted by hunger fell to 22.9 per cent last year, from 29.5 per cent in 2005. About 155 million children under five years old are affected.
"We see there is a decline - we also know that decline is not as fast as we would like ... to meet the SDG targets," said Victor Aguayo, Unicef's director for nutrition.
The number of children who were short for their age fell by 40 per cent between 1990 and 2015, and Mr Aguayo said this decline should continue.
Progress hinges on improving diets for women and children, improving the status of women in society, and lowering poverty levels, he said.
On the other hand, there has been a worrying increase of child obesity, with an estimated 41 million children around the world now overweight.
"Obesity is going to increasingly affect the poor, caused by poor diet and poor lifestyle," Mr Aguayo said.
Asia has the largest number of hungry people - 520 million - and sub-Saharan Africa has the highest proportion of hungry, affecting 20 per cent of the population.
Access to food has been affected by war, droughts linked to last year's El Nino weather phenomenon and a global economic slowdown, the agencies said.
A drop in employment rates and wages, and erosion of social safety nets, may result in a return of hunger in countries that have already eradicated it, said Jose Graziano da Silva, director-general of FAO.
"To save lives, we must save livelihoods also. This is the way forward that we see to eradicate hunger and extreme poverty once and for all," he said.