The number of people suffering from hunger last year rose at the fastest pace since at least the beginning of this century, as conflicts and climate-related issues curbed access to food.

Those categorized as hungry increased by about 38 million to 815 million in 2016, accounting for 11 percent of the global population, according to a report from the United Nations. The findings also show that food security has worsened in some places amid economic slowdowns, while 13 percent of adults are obese.

"These recent estimates are a warning signal that achieving the goal of a world without hunger and malnutrition by 2030 will be challenging," the U.N. Food and Agriculture Organization and four other agencies said in the report published Friday. "Deteriorations have been observed most notably in situations of conflict, often compounded by droughts or floods linked in part to the El Niño phenomenon."

More than half of those hungry live in areas affected by violent conflicts that have crippled local agriculture and restricted access to food supplies, with African nations being among the worst-hit. Famine was declared earlier this year in South Sudan and lasted several months, while Nigeria, Somalia and Yemen have suffered more food shortages. The increase in undernourishment also came as a gauge of food prices rebounded from a seven-year low, even amid a global glut of grains.

Some key findings:

● One-fifth of those in Africa and 12 percent in Asia were hungry.

● 155 million children younger than 5 were too short for their age.

● 52 million children aren't heavy enough for their height.

● One-third of people in eastern Africa were undernourished.

● Adult obesity is also rising everywhere at a faster pace.

A number of countries heavily dependent on shipping out commodities have seen export and fiscal revenue plunge in recent years amid lower oil and mineral prices, according to the report. That has hurt food availability and the ability to protect poor households against higher domestic food prices.

While the amount of undernourished people around the world rose last year to the highest level since 2008, it was still about 14 percent below a peak set in 2003. Under the 2030 Agenda for Sustainable Development, world leaders have pledged to try to eradicate hunger and malnutrition by 2030.

The situation is likely to improve this year, U.N. Food and Agriculture Organization chief José Graziano da Silva said at a news conference in Rome, citing an improving economy, fading odds of El Niño and progress made in conflict-affected areas.

The report was jointly prepared with the U.N.'s International Fund for Agricultural Development, the World Food Program, the World Health Organization and the United Nations Children's Fund.