Nearly one in nine people in the world are going hungry, with the coronavirus pandemic exacerbating already worsening trends this year, said a UN report published on Monday.
Economic slowdown and climate-related shocks are pushing more people into hunger, while the high cost of nutritious food contributes to undernourishment and growing rates of obesity in adults and children.
"After decades of long decline, the number of people suffering from hunger has been slowly increasing since 2014," said the annual State of Food Security and Nutrition in the World report.
And the lack of nutritious food in people's diets was having costly "health and environmental consequences".
Nearly 690 million people are hungry, or 8.9 per cent of people around the globe, the UN found.
That number rose by 10 million people in just one year to 2019, and by 60 million in the past five years, the study found.
It said eradicating hunger by 2030, one of the UN's sustainable development goals set five years ago, would be impossible if trends continued.
The report said that by 2030, more than 890 million people, or 9.8 per cent of the world's population, could be affected by hunger.
Five UN agencies co-wrote the report: the Food and Agriculture Organisation; the International Fund for Agricultural Development; the UN Children's Fund; the World Food Programme; and the World Health Organisation.
Last year, the report estimated that more than 820 million people were going hungry, but figures were recalculated after revised data from China covering years before.
When measuring moderate and severe food insecurity in 2019, the number balloons from 690 million to 2 billion people without "regular access to safe, nutritious and sufficient food".
The Covid-19 pandemic, which has hit hard in nations with widespread poverty, could mean another 83 million to 132 million people become undernourished this year, the report said.
About a quarter of Africa's population could go hungry by 2030 from 19.1 per cent today, already twice the world average.
In Asia, the number of hungry people decreased by 8 million people since 2015, although the continent is still home to more than half the world's undernourished people.
Trends in Latin America and the Caribbean are worsening, with 9 million more hungry people last year than in 2015.
"A key reason why millions of people around the world suffer from hunger, food insecurity and malnutrition is because they cannot afford the cost of healthy diets," the report said.
Adult obesity is on the rise in all regions, with healthy diets of fruit, vegetables and protein-rich foods unaffordable to about 3 billion people.
More than 57 per cent of people in sub-Saharan Africa and South Asia cannot afford a healthy diet.
Low-income countries rely on starchy staples such as cereals and tubers that can cost 60 per cent less than healthy diets, but lack enough proteins and key vitamins and minerals to reduce infections and ward off disease.
The report found 21.3 per cent of children under 5, or 144 million, had their growth stunted by malnutrition, most of them in Africa or Asia.
Another 6.9 per cent were "wasted" with nutritional imbalances, while 5.6 per cent were overweight.
Of the overweight children, 45 per cent come from Asia and 24 per cent from Africa, underscoring how malnutrition can cause undernutrition and obesity.
Current patterns in food consumption are estimated to result in health costs of more than $1.3 trillion (Dh4.78tn) a year by 2030.
But healthier diets could lower those costs by up to 97 per cent, the report estimated, saying a vegetarian diet could have associated health costs of less than $100 million.
Costs are also associated with greenhouse gas emissions caused by today's food production, which could also be reduced by alternative diets.
The report said high prices for healthy food were caused by factors ranging from insufficient diversification and inadequate food storage to domestic subsidies that favour staples.
But it called for an "urgent rebalancing of agricultural policies and incentives".
