Extreme weather events were a leading cause of global hunger rising last year, with women, babies, and old people particularly vulnerable to the worsening trend, a UN report said Tuesday.
Increasingly frequent shocks such as extreme rainfall or temperatures, as well as droughts, storms, and floods, helped push the number of undernourished people to 821 million in 2017, it said.
That figure, equivalent to about one in nine people globally, was up from 804 million in 2016, according to the annual report "The State of Food Security and Nutrition in the World".
"The number of people who suffer from hunger has been growing over the past three years, returning to levels that prevailed almost a decade ago. Equally of concern is that 22.2 percent of children under five are affected by stunting in 2017," said the document.
Low- and middle-income countries, in particular, were harshly impacted by ever-more frequent climate extremes.
"Africa is the region where climate shocks and stressors had the biggest impact on acute food insecurity and malnutrition, affecting 59 million people in 24 countries and requiring urgent humanitarian action," the report said.
Trends were also worsening in South America.
"If we are to achieve a world without hunger and malnutrition in all its forms by 2030, it is imperative that we accelerate and scale up actions to strengthen the resilience and adaptive capacity of food systems and people's livelihoods in response to climate variability and extremes," it added.
While floods, droughts, and other extreme weather events have always occurred, scientists say global warming is boosting the frequency and severity of such events.
In countries where conflict and climate shocks coincide, the impact on food insecurity was even more relentless, the report said. Nearly 66 million people worldwide required urgent humanitarian assistance last year.
Syria, where agriculture is one of the few sectors to have survived the seven-year war, saw its harvest hit by rising temperatures and drought.
Already down 40 percent from pre-conflict levels -- from 4 million tonnes to around 2.5 million tonnes --, Syria's cereal production "will suffer a new reduction" this year, the UN Food and Agriculture Organization's director of emergencies Dominique Burgeon said.
"Syria has seen a problem of seasonality, quantity and distribution of rainfall, and these factors combined have led to the overall weakening of the agricultural sector," he told AFP by phone.
Yemen has suffered an even worse fate, with 35 percent of the population undernourished, Burgeon said, making the war-torn nation home to the world's "most acute food crisis today".
The UN noted that women worldwide are especially vulnerable to the impact of climate extremes, particularly in countries where even a semblance of gender parity remains a distance dream.
This is because they often lack access to wealth, land, education and healthcare.
For instance, 90 percent of Lake Chad has dried up because of rising temperatures, forcing women to walk further to collect water for their families.
In India, limited resources coupled with entrenched gender inequalities saw poor families feed their boys better than girls when resources were limited.
Babies and young children were more at risk of long-term problems, and even of dying, from diarrhoea caused by disease following floods that rob people of clean water for drinking and sanitation.
Old and disabled people were also hard hit.
"In Vietnam, the elderly, widows, disabled people, single mothers, and households headed by women with small children were least resilient to floods and storms and slow-onset events such as recurrent droughts," the report said.
The UN also pointed to the global rise of obesity in adults, particularly in North America, but also in Africa and Asia.
Governments around the world have taken steps to combat the overweight epidemic, with the UK, France, Norway, and Mexico rolling out taxes on sugary soft drinks, for instance.
One in eight adults -- more than 672 million people worldwide -- are classified as obese.